22 Abdominal Masses: Solid Organs and Gastrointestinal

Thomas J. Kearney

Objectives

1. To describe the causes of ; to discuss the role of imaging and biopsy; to discuss the most frequently encountered benign and malig- nant liver masses and their management. 2. To describe the differential diagnosis of a pancre- atic mass; to discuss the most useful imaging studies and the role of biopsy. 3. To understand the relationship of the pancreatic duct to the common bile duct and how this may affect the diagnosis and treatment of a pancreatic mass; to discuss the management of cysts of the pancreas. 4. To describe the causes of hypersplenism; to discuss the common of hypersplenism and contrast with ; to discuss the role and consequences of splenec- tomy in the treatment of splenic disease. 5. To discuss the most frequently encountered retroperitoneal masses; to contrast the manage- ment of lymphomas and sarcomas.

Cases

Case 1 A 46-year-old male police officer noticed mild pressure in his when he bent to tie his shoes. His colleagues teased him that he was getting fat. However, he had not gained any weight. Further question- ing revealed early satiety, and revealed a large epigastric mass that was firm but not hard. It was not tender. A com- puted tomography (CT) scan was ordered.

409 410 T.J. Kearney

Case 2 A 72-year-old woman presented to the hospital with hematemesis. She had noticed a 10-pound and early satiety over the past month. She denied changes in her bowel habits or . Physical examination revealed a midline epigastric mass along with an enlarged . Neither was tender. A CT scan was ordered.

Case 3 A 22-year-old man complained of bleeding gums and epistaxis. Exam- ination was otherwise unremarkable. He did not have a left upper quadrant mass. Platelet count was 15,000/mL.

Case 4 A 48-year-old man presented with increasing abdominal girth and decreased appetite. Examination revealed a large left-sided mass. A CT scan revealed a large mass in the retroperitoneum with fat density.

Case 5 A 45-year-old man presented with intermittent and blood in his stools. Examination revealed a mass in the midabdomen. A CT scan suggested a colon cancer that was locally advanced. Colonoscopy revealed a cancer.

Introduction

Abdominal masses may be caused by a large variety of pathologic con- ditions. All abdominal masses need to be thoroughly and expeditiously evaluated, sometimes with significant urgency. A detailed history and physical examination, combined with knowledge of normal anatomy, allow the physician to generate a reasonable differential diagnosis. Additional diagnostic tests then can be obtained. In certain situations, notably rupturing abdominal aortic aneurysms, the physician must take the patient directly to the operating room without further testing to avoid exsanguination. Several classification systems are available to help guide evaluation of a patient with an abdominal mass (Table 22.1). Surgeons often use

Table 22.1. Classification systems for abdomi- nal masses. Anatomic Organ based Location Etiology Clinical course Acute Chronic Urgent 22. Abdominal Masses: Solid Organs and Gastrointestinal 411

Table 22.2. Anatomic classification. Organ based Liver Pancreas Spleen Renal Vascular Gastrointestinal Connective tissue Location based Abdominal wall Intraperitoneal Pelvic Right lower quadrant Left lower quadrant Mid-pelvis Retroperitoneal Flank Epigastric Right upper quadrant Left upper quadrant anatomic systems (Table 22.2). These systems can be divided into an organ-based system or a location-based system. In addition, an etio- logic system (Table 22.3) is equally valuable and may be preferred by some. As always, the physician must be sure the patient does not have an emergency situation requiring immediate operation.

General Evaluation

A detailed history must include information about the onset of the mass (sudden vs. chronic). Incidentally discovered masses often repre- sent . Symptomatic and acute masses imply an infectious or inflammatory cause. Abdominal aneurysm rupture usually is sudden and acute. (See Chapter 23 for vascular abdominal masses.) Changes in size over time and symptoms associated with the gastrointestinal, hepatobiliary, urinary, or gynecologic systems can provide clues to the

Table 22.3. Etiologic classification. Neoplastic Benign Malignant Primary Metastatic Infectious Bacterial Parasitic Fungal Traumatic Inflammatory Congenital Degenerative 412 T.J. Kearney

nature of the mass. These symptoms could include nausea, , , melena, jaundice, vaginal bleeding, and hematuria. The physician should ask about the presence of along with details about pain quality, location, radiation, timing, severity, and factors that alleviate or exacerbate the pain. Details about preexisting or chronic conditions are required. Physical examination should include an evaluation of the patient’s general status, including vital signs and any evidence of impending cardiac or respiratory collapse. Try to identify the general location of the mass. Contour and texture (hard, fluctuant) provide clues to the diagnosis. Evidence of bowel perforation, such as diffuse abdominal tenderness or tympany from free air, should be sought. Examination of the chest as well as rectal and pelvic examination are essential. Masses that are tender and associated with signs of sepsis (fever, hypotension) or masses associated with perforation require urgent evaluation. Upon completion of the history and physical examination, the physician usually knows if urgent evaluation and treatment are needed or if more leisurely evaluation is safe. In nonurgent situa- tions, radiologic evaluation plays a key role. Plain radiographs of the chest and abdomen combined with basic laboratory evaluation (com- plete blood count with differential, electrolytes, renal and liver func- tion, urinalysis, pregnancy test) are the first steps in further evaluation. The plain radiographs should include a flat and upright abdominal film along with posteroanterior and lateral chest radiographs. These films detect signs of perforation or obstruction as well as mass effect. After initial evaluation, the probable site of abnormality guides further workup. Findings suggestive of gastric or colonic disease would lead to endoscopic evaluation or possibly gastrointestinal (GI) contrast studies. If a CT scan is contemplated, it must be performed prior to GI contrast studies. Masses of the uterus and ovaries usually are evaluated initially with ultrasound, either transabdominal or transvaginal. Ultra- sound also is useful for suspected biliary disease as well as for evalua- tion of nonurgent abdominal aortic aneurysms. Masses of the solid organs (liver, spleen, and pancreas) or the retroperitoneum require CT scan, almost always with oral and intravenous contrast. Magnetic reso- nance imaging (MRI) is useful for further characterization of some solid organ masses. Intravenous pyelography (IVP) is useful for evaluation of the urinary system. Cystoscopy is useful for bladder evaluation and should be included in any evaluation of hematuria. Radionuclide imaging is less used than previously due to the excellent anatomic detail available from modern CT scanning. Angiography occasionally is used in the evaluation of operative approaches for abdominal masses. Mag- netic resonance angiography is an evolving technique that may provide similar information less invasively than angiography.

Liver Masses

Liver masses may present with symptoms or may be discovered inci- dentally on scans done for other reasons. Multiple causes are possible (Table 22.4). Pain usually is dull, aching, and fairly constant. Fever and 22. Abdominal Masses: Solid Organs and Gastrointestinal 413

Table 22.4. Liver masses. Tumors Cysts Abscesses Benign Acquired Pyogenic Hemangioma Parasitic (hydatid) Adenoma Traumatic Focal nodular hyperplasia Malignant: primary Congenital Amebic Hepatoma Single Cholangiocarcinoma Multiple Angiosarcoma Malignant: metastatic Fungal Unresectable Resectable

tenderness could represent an infectious etiology, such as abscess. A personal history of cancer, particularly colon and rectal cancer, could be a clue to hepatic metastases. Patients with a history of alcoholism or hepatitis leading to cirrhosis are at risk for hepatocellular cancer. The patient in Case 1 had none of these. His occupation as a police officer may have exposed him to blunt abdominal trauma while arresting a suspect. This could lead to a hematoma, but he could not recall any particular incident. A CT scan revealed a large 12-cm hemangioma of the left lobe of the liver. The patient’s symptoms were managed with mild analgesics, and the decision was made to avoid surgical resection in this patient. On follow-up the next year, size and symptoms had increased. A left hepatectomy was performed. A scheme for manage- ment of liver tumors is presented in Algorithm 22.1.

Tumors Tumors of the liver can be classified as benign or malignant. Heman- gioma is the most common benign tumor of the liver, occurring in up to 20% of patients in some autopsy series. They usually are asympto- matic and require removal only if disabling symptoms are present. The risk of rupture is quite low, even in large hemangiomas. The diagnosis can be confirmed with near certainty by an MRI or nuclear imaging studies. Other benign tumors include hepatic adenomas associated with oral contraceptive use in young women. Hepatic adenomas that are symptomatic or larger than 5cm usually are removed due to the 10% to 20% chance of subsequent rupture. Focal nodular hyperplasia (FNH) of the liver also usually is asymptomatic. It is not associated with oral contraceptives, and the etiology is not clear. Resection rarely is needed. Malignant tumors of the liver can be either primary or secondary. In the United States, metastatic liver tumors are 20 times as common as primary tumors. Almost every cancer site can metastasize to the liver, and liver metastases represent systemic disease. Only in the specific setting of colon and rectal cancer can liver metastases poten- tially represent regional disease without systemic spread. Patients with one or several metastases technically amenable to resection and no sign of systemic disease can expect a 25% to 35% 5-year survival 414 T.J. Kearney

History, physical exam, lab, CT scan

Metastatic Benign liver liver tumor tumor Primary liver tumor Unresectable *

Hemangioma, adenoma, FNA Resectable

Palliative care

Symptoms, size Asymptomatic

Resection Observation

Resectable (colorectal, neuroendocrine)

* Consider ablation (thermal, cryo) in selected cases Algorithm 22.1. Algorithm for evaluation and treatment of liver tumors. FNA, fine-needle aspiration.

(Table 22.5). Most patients’ metastases are not resectable. Patients with symptomatic liver metastases from neuroendocrine tumors also benefit from liver resection even if this is not curative. Primary malignant liver tumors are rare in the United States, but worldwide these represent a significant cancer burden. (also known as hepatoma) usually arises in patients with cirrhosis. Patients present with , weight loss, and jaun- dice. The underlying parenchymal severely limits the ability to safely perform liver resection in most patients. Patients able to have resection can have 5-year survival exceeding 25%. Patients undergoing liver transplantation for end-stage liver disease sometimes have incidentally discovered small hepatomas. The prognosis for these 22. Abdominal Masses: Solid Organs and Gastrointestinal 415 patients is much better. Other forms of primary liver tumors include intrahepatic cholangiocarcinoma and angiosarcoma. Patients with unresectable and incurable liver tumors do not benefit from . The diagnosis usually can be obtained with core needle biopsy or fine- needle aspiration. Occasionally, biopsy requires laparoscopic or open surgical techniques, but this situation is rare.

Cysts Hepatic cysts can be classified as acquired or congenital. Acquired cysts usually are either parasitic or posttraumatic. In South American or Mediterranean countries and Australia, echinococcal (hydatid) cysts are prevalent. Patients present with symptoms of abdominal pain.

Table 22.5. Five-year survival following liver resection for metastases. Number 5-Year survival of cases (%) Comments Reference (year, location) 56 25 Cobourn et ala (1987, Toronto) 859 33 Summary data from 24 Hughes et alb (1988, Sacramento) institutions 100 30 Doci et alc (1991, Milan) 266 31 Scheele et ald (1991, Erlangen) 280 25 Rosen et ale (1992, Rochester) 204 32 Gayowski et alf (1994, Pittsburgh) 81 32 Yasui et alg (1997, Nagoya) 456 38 6-year consecutive series Fong et alh (1997, New York) 123 34 Taylor et ali (1997, Toronto) 94 30 Only include 94 of 231 Ambiru et alj (1998, Chiba) reported cases with definite negative margins 111 25 25-year consecutive series Ohlsson et alk (1998, Lund) a Cobourn CS, Makowka L, Langer B, et al. Examination of patient selection and outcome for hepatic resection for metastatic disease. Surg Gynecol Obstet 1987;165:239–246. b Hughes KS, Simon R, Songhorabodi S, et al. Resection of the liver of colorectal carcinoma metastases: a multi- institutional study of indications for resection. Surgery (St. Louis) 1988;103:278–288. c Doci R, Gennari L, Bignami P, et al. One hundred patients with hepatic metastases from colorectal cancer treated by resection: analysis of prognostic determinants. Br J Surg 1991;78:797–801. d Scheele J, Stangl R, Altendorf-Hofman A, et al. Indicators of prognosis after hepatic resection for colorectal sec- ondaries. Surgery (St. Louis) 1991;110:13–29. e Rosen CB, Nagorney DM, Taswell HF, et al. Perioperative blood transfusion and determinants of survival after liver resection for metastatic colorectal carcinoma. Ann Surg 1992;216:493–505. f Gayowski TJ, Iwastsuki S, Madariaga JR, et al. Experience in hepatic resection for metastatic colorectal cancer: analysis of clinical and pathologic risk factors. Surgery (St. Louis) 1994;116:703–711. g Yasui K, Hirai T, Kato T, et al. A new macroscopic classification predicts prognosis for patient with liver metas- tases from colorectal cancer. Ann Surg 1997;226:582–586. h Fong Y, Kemeny N, Paty P, et al. Treatment of colorectal cancer: hepatic metastasis. Semin Surg Oncol 1996;12:219–252. i Taylor M, Forster J, Langer B, et al. A study of prognostic factors for hepatic resection for colorectal metastases. Am J Surg 1997;173:467–471. j Ambiru S, Miyazaki M, Ito H, et al. Resection of hepatic and pulmonary metastases in patients with colorectal car- cinoma. Cancer (Phila) 1998;82:274–278. k Ohlsson B, Stenram U, Tranberg K-G. Resection of colorectal liver metastases: 25-year experience. World J Surg 1998;22:268–277. Source: Reprinted from Hemming A, Gallinger S. Liver. In: Norton JA, Bollinger RR, Chang AE, et al, eds. Surgery: Basic Science and Clinical Evidence. New York: Springer-Verlag, 2001, with permission. 416 T.J. Kearney

Eosinophilia is common. A calcified cyst often can be seen on plain radiography. Treatment requires excision of the cyst, with special care taken to avoid spillage of the parasitic contents. Traumatic cysts lack an epithelial lining, and thus they are not true cysts. They represent hemorrhage into the liver parenchyma following significant trauma. Management is conservative observation. Congenital cysts usually are single, but they may be multiple. They usually are asymptomatic. Patients with multiple cysts often have poly- cystic kidneys as well. Treatment rarely is required. Rare cases of cystic neoplasms of the liver have been reported.

Abscess The final category of liver mass is the hepatic abscess. Pyogenic bac- terial abscess usually follows an episode of biliary or sepsis. Patients have fever and rigors. Treatment requires percu- taneous drainage and antibiotics. Amebic abscess presents with similar findings. Treatment with metronidazole is effective, and drain- age is required only in complicated cases. Fungal abscess usually is associated with immunosuppression.

Pancreatic Masses

In Case 2, the patient’s history and examination immediately do not suggest the cause of her problem. A CT scan revealed an enlarged spleen along with a heterogeneous mass posterior to the stomach. The head and body of the pancreas were well visualized, but the tail seemed to blend into the mass. The mass did not appear to invade surround- ing structures and radiographically appeared resectable. To further evaluate the pancreatic mass, endoscopic retrograde cholangiopancre- atography (ERCP) was performed. The bile duct was normal, as was most of the pancreatic duct. The pancreatic duct in the tail of the pan- creas did not communicate with the mass, but it was displaced cau- dally. The patient underwent a distal pancreatectomy. Pathology revealed a cystadenoma of the pancreas. The presentation of a pancreatic mass is dependent on the location and nature of the mass. Masses in the head of the pancreas (usually neoplasms) obstruct the common bile duct due to proximity. These patients present with obstructive jaundice, and the masses tend to be only a few centimeters in diameter. Neoplasms in the body or tail of the pancreas grow larger and cause symptoms by impinging on sur- rounding structures. In this case, the mass had caused splenic vein thrombosis, leading to bleeding gastric varices from left-sided portal hypertension. The mass effect on the posterior stomach led to early satiety and weight loss. Pancreatic enlargement associated with pan- creatitis usually involves signs of systemic inflammation. Patients with pancreatic pseudocysts usually have a past history of pancreatitis. An algorithm for the evaluation and treatment of pancreatic masses is pre- sented in Algorithm 22.2. 22. Abdominal Masses: Solid Organs and Gastrointestinal 417

History, physical exam, CT scan

Pseudocyst Pancreatic Cystic cancer

Metastatic, not resectable

Size

No metastases No metastases, vessels clear Palliative care, stent if jaundiced >5 cm, >6 weeks

Resolving

Internal drainage * Resection, avoid preoperative stents

Observe * Biopsy to exclude neoplasia

Algorithm 22.2. Algorithm for evaluation and treatment of pancreatic tumors.

Tumors Solid pancreatic masses almost always represent neoplasia. Almost all pancreatic tumors are malignant. Classically, tumors of the body and tail of the pancreas grow silently and eventually produce symp- toms by invasion of surrounding organs. They almost never are resectable. Confirmation of the diagnosis can be made with percuta- neous fine-needle aspiration guided by ultrasound or CT. Tumors of the head of the pancreas occasionally come to attention earlier due to the development of obstructive jaundice. The proximity 418 T.J. Kearney

of the common bile duct to the head of the pancreas allows small pan- creatic tumors the opportunity to obstruct the bile duct. This causes symptoms when the is still small. A patient with painless obstructive jaundice should be assumed to have until proven otherwise. A small proportion of such patients (15%) have no evidence of systemic disease on imaging. These patients are candidates for curative pancreaticoduodenectomy (Whipple proce- dure). Patients with potentially resectable cancers of the head of the pancreas should not undergo percutaneous needle biopsy. This pro- cedure may risk seeding the abdominal cavity and eliminating a chance of cure. The techniques of pancreatic surgery are advanced enough that mortality rates should be under 3% at specialized centers. Occasionally, an intraoperative diagnosis of pancreatic cancer cannot be made. If the tumor is technically resectable, the surgeon must be pre- pared to perform definitive resection without a tissue diagnosis. Five- year survival may be as high as 20% with truly localized disease resected with a negative margin and combined with adjuvant therapy.

Pseudocysts and Cystic Tumors Some pancreatic masses are cystic in nature. The differential diagnosis is between a true cystic neoplasm and a . Cystic neoplasms can be benign cystadenomas or malignant cystadenocar- cinomas. Pancreatic pseudocysts arise in the setting of pancreatitis. Persistent pain and the development of an abdominal mass follow- ing a bout of acute pancreatitis should raise suspicion about a pseudo- cyst. About one third to one half of acute pseudocysts resolve spontaneously within about 6 weeks. Pseudocysts that are present longer than 6 weeks are termed chronic pseudocysts. Those that become chronic can be observed if small and asymptomatic. Chronic pseudocysts with symptoms of pain, obstruction, and infection usually require treatment. Various treatment options exist, including external percutaneous drainage, internal endoscopic drainage (cystogastros- tomy), and internal surgical drainage (cystogastrostomy or cystoje- junostomy). Percutaneous drainage works well for some patients, but, when the technique fails, the patient often has a complicated course. Endoscopic drainage is relatively new. Surgical drainage is the gold standard with recurrence rates less than 10%. Surgical drainage allows for biopsy of the pseudocyst wall to exclude cystic malignancy. Cystic neoplasms can be either benign or malignant. They account for about 20% of cystic masses of the pancreas. The treatment for malignant cystic tumors of the pancreas is resection. These malignant tumors have much higher cure rates with surgical resection compared to noncystic tumors. Some series report 5-year survival rates greater than 50%.

Splenomegaly

In Case 3, the patient has thrombocytopenia. Further testing included a bone marrow aspirate revealing an increased number of megakary- ocytes. Platelet-associated immunoglobulin G (IgG) antibodies were 22. Abdominal Masses: Solid Organs and Gastrointestinal 419

Table 22.6. Primary and secondary hypersplenism. Primary Secondary Hereditary spherocytosis Cirrhosis Hemoglobinopathies (sickle cell) Splenic vein thrombosis Hemolytic anemia Myeloid metaplasia Idiopathic thrombocytopenic purpura Chronic myelogenous leukemia Thrombotic thrombocytopenic purpura

present in serum. The diagnosis of idiopathic thrombocytopenic purpura (ITP) was made. The patient was treated with prednisone. Unlike 80% of patients, he did not respond. He was vaccinated against encapsulated organisms, and a laparoscopic splenectomy was per- formed, revealing a mildly enlarged spleen. His platelet count returned to normal.

Hypersplenism and Splenomegaly The patient in Case 3 had signs of hypersplenism (increased function of the spleen). Although it was not appreciated on physical examina- tion, he had mild splenomegaly. Hypersplenism and splenomegaly are separate findings related to function and size of the spleen. Due to the spleen’s location under the left rib cage, mild enlargement often can be missed on physical examination. One of the normal functions of the spleen is to clear abnormal and aged cellular elements from the blood. If an increased number of abnormal cells are presented to the spleen with increased destruction, the patient has primary hyper- splenism. Alternatively, a patient may develop splenic enlargement due to intrinsic splenic disease that leads to secondary hyper- splenism (Table 22.6). In the case presented, the patient’s spleen is inherently normal, but it has enlarged as a consequence of increased clearance of abnormal platelets. A variety of illnesses can lead to splenomegaly (Table 22.7). Malaria probably is the most common cause of splenomegaly throughout the world. A variety of bacterial, parasitic, and viral infections can lead to increased proliferation of immune system cells (e.g., mononucleosis). Sarcoidosis can lead to granulomatous enlargement of the spleen.

Table 22.7. Causes of splenomegaly. Malaria Granulomatous disease Rheumatoid disease Hematologic disorders Cirrhosis Lymphoma Splenic abscess Storage disease Leukemia Splenic cysts Viral infection 420 T.J. Kearney

Metabolic abnormalities, such as Gaucher’s disease, can lead to accu- mulation of unmetabolized products in the spleen. A variety of hema- tologic disorders, such as ITP, thrombotic thrombocytopenic purpura, hereditary spherocytosis, and b-thalassemia, lead to some splenic enlargement as a consequence of primary hypersplenism. In primary hypersplenism, the spleen inherently is normal, but it enlarges in size and increases function in response to an increased work load. Disor- ders such as cirrhosis, portal vein obstruction, and congestive heart failure can lead to splenomegaly due to restricted venous outflow. Myeloid metaplasia (also known as myelofibrosis) leads to bone marrow failure. The spleen compensates and becomes a major site of erythropoiesis. In chronic myelogenous leukemia, massive spleno- megaly can develop and lead to difficult problems with anemia. Cysts and abscesses are rare, but they can produce splenic enlargement. All of these situations reflect secondary hypersplenism: increased function resulting from abnormally increased size.

Splenectomy The most common reason for splenectomy in the United States today is splenic trauma. The spleen is the organ most commonly injured in blunt trauma. The diagnosis is made based on the mechanism of injury and left upper quadrant pain and tenderness. Splenic injury also may be relatively asymptomatic and discovered on CT scan following blunt trauma. The management of splenic trauma can involve observation in the stable patient. In the unstable patient, splenectomy and occasionally splenorrhaphy are used. The degree of splenic injury and the presence of associated injuries guide the surgeon to either removal or repair. The presence of splenomegaly is not an indication for elective splenectomy by itself. Rather, the underlying condition must be one that responds to splenectomy. Elective splenectomy most commonly is performed for hematologic disorders, with ITP being the most common reason in most series (Table 22.8). Surgical staging of Hodgkin’s disease was per- formed in the past to help decide on treatment modalities. This tech- nique is used less today due to the increasing use of systemic chemotherapy even in early-stage patients. In the past, open splenec- tomy was performed through a left upper quadrant incision. Increas- ingly, laparoscopic techniques are used to remove the spleen (Table 22.9). During laparoscopic splenectomy, the spleen is morcellated into fragments and removed. The size of the spleen is the primary deter- minant of the decision to use laparoscopic or open techniques. Laparo- scopic removal is preferred if an experienced team is available. Whether performed electively or emergently, there are some com- plications common to all splenectomies. Injury to the greater curvature of the stomach during ligation of the short gastric vessels can lead to perforation. Hemorrhage is seen in 5% of splenectomies. Atelectasis is more common following open splenectomy. Accessory splenic tissue is present in over 10% of patients and can cause relapse in some of the hematologic conditions. Overwhelming postsplenectomy infection 22. Abdominal Masses: Solid Organs and Gastrointestinal 421

Table 22.8. Indications for elective splenectomy. ITP (idiopathic thrombocytopenia purpura) Hereditary spherocytosis Autoimmune hemolytic anemia Staging for Hodgkin’s disease Lymphoma Thrombocytopenic thrombotic purpura AIDS-related thrombocytopenia Leukemia Splenic abscess Gaucher’s disease Myelofibrosis Splenic infarct Source: Reprinted from Lefor AT, Phillips EH. Spleen. In: Norton JA, Bollinger RR, Chang AE, et al, eds. Surgery: Basic Science and Clinical Evidence. New York: Springer-Verlag, 2001, with permission.

(OPSI) is a unique complication that can occur in about 4% of patients. Patients without are particularly susceptible to infection with Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningi- tidis. This complication is life threatening. Early institution of anti- biotics is needed for postsplenectomy patients who present with nonspecific flu-like symptoms to prevent progression of OPSI. Prior to elective splenectomy and following emergent splenectomy, all patients should be vaccinated with pneumococcal vaccine to prevent OPSI.

Retroperitoneal Masses

The patient in Case 4 had further evaluation, including a chest CT that revealed no sign of disease outside of the retroperitoneum. He under- went exploratory laparotomy with en bloc resection of the mass includ- ing the left colon, the left , and the adrenal gland. Pathology review showed an intermediate-grade liposarcoma. The retroperi- toneal margin was involved focally. It is common to have microscopi- cally involved margins, even with en bloc resection of retroperitoneal sarcoma. Most patients have a recurrence. Repeat resection is indicated, since recurrences can remain low grade. Eventually, many of these low- grade sarcomas become high-grade with an increased chance of sys- temic (usually pulmonary) metastases.

Tumors The differential diagnosis of retroperitoneal masses is fairly limited. Retroperitoneal sarcomas usually are liposarcomas or leiomyosarco- mas. A CT scan and MRI can be used to assess the nature and poten- tial resectability of retroperitoneal masses. Other potential diagnoses include testicular tumors in men and primary germ cell tumors in both sexes. Evaluation should include serum markers for germ cell 422 T.J. Kearney 2,253 720 2,038 270 ± ± ± ± 2,550 12,827 1,849 8,400 8,7521,418 4,372 3,627 nical Evidence. New York: nical Evidence. New ± ± ± ± 9. randomized studies; class II, prospective 1.50.5 18,015 17,071 6.80.2 16,362 13,196 ± ± ± ± 168 1 2.3 318 2 8.8 ± ± 7131 385 17 0 3.0 12 14.5 2 5.8 64 359 ± ± ± ± room size Major Postoperative Total room Operating Spleen Operating time (min) EBL (mL) (cm) morbidity stay (days) cost ($) cost ($) n OpenConversionLap 3 (%) Lap 28 15 10 127 196 261 8 8.6 OpenOpen 15 10 116 131 Conversion 1 (%) SD. ± c b a Reprinted from Lefor AT, Phillips EH. Spleen. In: Norton JA, Bollinger RR, Chang AE, et al, eds. Surgery: Basic Surgery and Cli Basic Surgery AE, et al, eds. Surgery: Phillips EH. Spleen. In: Norton JA, Bollinger RR, Chang AT, Lefor Reprinted from (1997) Diaz J, Eisenstat M, Chung R. ADiaz J, Eisenstat M, Chung R. 1997;173:348–350. Am J Surg splenectomy. study of laparoscopic case-controlled Delaitre B, Pitre J. Laparoscopic splenectomy versus open splenectomy: a comparative study. Hepatogastroenterology 1997;44:45–4 Hepatogastroenterology splenectomy versus open splenectomy: a comparative study. J. Laparoscopic B, Pitre Delaitre Smith CD, Meyer TA, Goretsky MJ, et al. Laparoscopic splenectomy by the lateral approach. Surgery (St. Louis) 1996;120:789–794. Surgery splenectomy by the lateral approach. MJ, et al. Laparoscopic Goretsky Smith CD, Meyer TA, Source: Springer-Verlag, 2001, with permission. Springer-Verlag, Delaitre Lap 28 183 3 5.1 Table 22.9.Table Adult matched retrospective studies of laparoscopic versus open splenectomy for disease (level II evidence). Reference Procedure Lap: laparoscopy. mean Data are a b c Clinical studies are classified according to the design of the study and the quality of the resulting data. Class I, prospective to the design of study and quality resulting classified according Clinical studies are Diaz (1997) nonrandomized studies or case-controlled retrospective studies; class III, retrospective analyses without case controls. studies; class III, retrospective retrospective nonrandomized studies or case-controlled Smith (1996) 22. Abdominal Masses: Solid Organs and Gastrointestinal 423 tumors such as b-human chorionic gonadotropin (b-HCG) and a-feto- protein. The treatment of germ cell tumors requires systemic chemotherapy, and surgery is not needed. Retroperitoneal lymphoma also can present as an abdominal mass, although patients usually have lymphadenopathy elsewhere. Finally, intraabdominal spread from other more common gastrointestinal tumors can cause retroperitoneal masses. An algorithm for the evaluation and treatment of retroperi- toneal tumors is presented in Algorithm 22.3. When retroperitoneal tumors appear unresectable or when the sus- picion of lymphoma or germ cell tumor is high, percutaneous needle biopsy is appropriate. In the setting of a potentially resectable retroperitoneal sarcoma, percutaneous biopsy can lead to tumor seeding of the abdomen, preventing a curative resection. Patients with potentially resectable retroperitoneal masses should be prepared

History, physical exam, tumor markers, CT scan

Retroperitoneal sarcoma Lymphoma, germ cell tumor

Metastatic tumors

Resectable Percutaneous biopsy, systemic therapy

Unresectable

Palliative care, systemic therapy Resection

Algorithm 22.3. Algorithm for evaluation and treatment of retroperitoneal masses. 424 T.J. Kearney

for en bloc resection of the mass with attached organs as needed. Partial resection does not appear to aid survival. The most common reasons for unresectability include involvement of the aorta or cava along with intraoperative discovery of distant spread of disease. Neither radiotherapy nor adjuvant chemotherapy has demonstrated usefulness in the postoperative treatment of patients undergoing com- plete resection. Selected series reveal resectability rates ranging from 25% to about 75%.

Other Abdominal Masses

The patient in Case 5 was taken to the operating room and underwent a resection of the right and transverse colon together with a portion of the stomach and small bowel. Negative margins were achieved. He received postoperative adjuvant chemotherapy. Although this patient had an abdominal mass, careful questioning revealed that his primary symptoms were related to partial obstruction of the GI tract along with GI bleeding. Tumors of the stomach, small bowel, and colon can present as abdominal masses. However, the symptom complex usually is related to bleeding and obstruction. These symptoms and their evaluation are covered in Chapters 20 and 21. Abdominal and pelvic masses also can present from tumors of the ovaries. A large variety of ovarian tumors, both malignant and benign, can produce tumors of enormous size. All female patients with an abdominal mass should have a pelvic exam performed with imaging studies ordered as needed. The details of the management of ovarian masses are best addressed in the student’s obstetrics and gynecology rotation. Finally, large renal masses can present with an abdominal mass. The triad of flank mass, flank pain, and hematuria raise suspicion of a renal cell cancer. The discussion of this topic is covered in Chapter 37.

Summary

A patient who presents with a palpable abdominal mass, without signs or symptoms of obstruction or bleeding, probably has a mass arising from the liver, pancreas, spleen, or retroperitoneum. In certain circum- stances, gynecologic, gastrointestinal, or renal masses can be responsi- ble. A focused history and physical exam, combined with appropriate imaging studies, can help the student identify the anatomic origin of the mass. In addition, a general classification of the mass as neoplas- tic, infectious, or inflammatory usually can be made. Malignant neo- plastic masses usually require surgical resection for cure. Some benign neoplasms also require resection, while others safely can be observed. Infectious masses most often are treated with antibiotics, although undrained purulent collections usually require percutaneous drainage. In all cases, the physician should bear in mind that vascular masses, such as an abdominal aortic aneurysm, may require emergency repair rather than extended workup. 22. Abdominal Masses: Solid Organs and Gastrointestinal 425

Selected Readings

Flowers JL, Lefor AT. Laparoscopic splenectomy in patients with hematologic diseases. Ann Surg 1996;1996:19–28. Fong Y, Cohen AM, Fortner JG, et al. Liver resection for colorectal metastases. J Clin Oncol 1997;15:938–946. Fong Y, Sun RL. An analysis of 412 cases of hepatocellular carcinoma at a western center. Ann Surg 1999;229:790–800. Friedman RL, Hiatt JR. Laparoscopic or open splenectomy for hematologic disease; which approach is superior? J Am Coll Surg 1997;185:49–54. Hemming A, Gallinger S. Liver. In: Norton JA, Bollinger RR, Chang AE, et al, eds. Surgery: Basic Science and Clinical Evidence. New York: Springer- Verlag, 2001. Karakousis CP, Gerstenbluth R. Retroperitoneal sarcomas and their manage- ment. Arch Surg 1995;130:1104–1109. Karpoff HM, Klimstra DS. Results of total pancreatectomy for adenocarcinoma of the pancreas. Arch Surg 2001;136:44–47. Lefor A, Phillips E. Spleen. In: Norton JA, Bollinger RR, Chang AE, et al, eds. Surgery: Basic Science and Clinical Evidence. New York: Springer-Verlag, 2001. Lewis JJ, Leung D. Retroperitoneal soft-tissue sarcoma; analysis of 500 patients treated and followed at a single institution. Ann Surg 1998;228:355–365. Lieberman MD, Kilburn H. Relation of perioperative deaths to hospital volume among patients undergoing pancreatic resection for malignancy. Ann Surg 1995;222:638–645. Mulvihill S. Pancreas. In: Norton JA, Bollinger RR, Chang AE, et al, eds. Surgery: Basic Science and Clinical Evidence. New York: Springer-Verlag, 2001. Yeo CJ, Cameron JL. Pancreaticoduodenectomy for cancer of the head of the pancreas. Ann Surg 1995;221:721–733.