Large Pelvic Accessory Spleen Mimicking an Adnexal Malignancy in a Teenage Girl

Accessory Spleen Mimicking Adnexal Malignancy

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LARGE PELVIC ACCESSORY SPLEEN MIMICKING AN ADNEXAL MALIGNANCY IN A TEENAGE GIRL

Sheng-Mou Hsiao, Long-Chien Lee,1 and Ming-Hao Chang2

Abstract: A large pelvic accessory spleen in a teenage female is rare and may be (J Formos Med Assoc misdiagnosed as an adnexal tumor. A 17-year-old girl, gravida 0, had suffered from 2001;100:565–7) intermittent and dull pain in the lower abdomen for 1 month. Laboratory evaluation µ showed a low platelet count (136,000/ L). Abdominal sonography showed a large Key words: solid mass situated at the right pelvis, containing abundant vascular supply with low accessory spleen resistant blood flow. At laparotomy, an accessory spleen fed by a tortuous vascular adnexal tumor pedicle from the omentum was found and then excised. Histopathologic examination thrombocytopenia revealed congestive accessory splenomegaly. Follow-up platelet count returned to normal levels (374,000/µL). The importance of including accessory spleen in the differential diagnosis of a solid adnexal tumor with thrombocytopenia is emphasized.

Accessory spleen is present in approximately 10% of the At admission, the patient’s vital signs were stable. Physi- general population [1]. It is usually small in size (< 6 cm) and cal examination showed mild tenderness over the lower located near the splenic hilum, the tail of the pancreas, or the abdomen. Vaginal examination was not performed because greater omentum [1]. In atypical cases, the diagnosis is of no coital experience. Abdominal ultrasound showed a difficult preoperatively. Pelvic accessory spleen is rare and large, well-defined, heteroechoic, solid mass in the right side only a few cases have been reported [2, 3]. Here, we describe of the pelvis (Fig. 1). No ascites was found. Color Doppler a large pelvic accessory spleen in a teenage girl and discuss ultrasound demonstrated prominent blood flow in the mass the differential diagnosis of this adnexal solid mass. with low resistance index (RI; 0.49–0.39) and pulsatility index (0.70–0.48) (Fig. 2). The left ovary was not remarkable. Therefore, a right adnexal tumor was diagnosed, and malignancy with intermittent torsion was suspected. Laboratory ase Report evaluations demonstrated normal white blood cell count and C hemoglobin levels but a low platelet count (136,000/µL). Tumor markers including CA-125, carcinoembryonic antigen, A 17-year-old girl, gravida 0, visited our hospital on February human chorionic gonadotropin, and alpha-fetoprotein were 5, 1999, because of intermittent dull pain in the lower all within normal limits. abdomen for 1 month. Her menarche had occurred at 13 Laparotomy was performed on February 9, 1999, because years old. She had a regular menstrual cycle and had her last of the progressing abdominal pain. The operative findings menstrual period on January 25, 1999. There was no history were as follows: a wandering congestive mass (13 x 8 x 7 cm) of dysmenorrhea or hypermenorrhea. However, intermittent with a tortuous vascular pedicle that originated along the and dull pain in the lower abdomen had developed 1 month dorsal aspect of the greater omentum situated in the cul- prior to her visit and was refractory to medical treatment from de-sac; unremarkable uterus and ovaries; and a normal-sized local clinics. There was no recent body weight loss, poor spleen palpated in the left upper quadrant by an experienced appetite, rectal tenesmus, or urinary frequency. surgeon. Pelvic accessory spleen was diagnosed and the mass

Departments of Obstetrics and Gynecology, National Taiwan University Hospital, 1Taipei Municipal Women and Children's Hospital, and 2En Chu Kong Hospital, Taipei. Received: 21 November 2000. Revised: 8 January 2001. Accepted: 8 May 2001. Reprint requests and correspondence to: Dr. Ming-Hao Chang, Department of Obstetrics and Gynecology, En Chu Kong Hospital, 399 Fuhsing Road, San-shia Town, Taipei Hsien, Taiwan.

J Formos Med Assoc 2001 • Vol 100 • No 8 565 S.M. Hsiao, L.C. Lee, and M.H. Chang

Accessory spleens may cause clinical symptoms by compression of the adjacent organs, rupture, torsion, or infarction [4, 5]. Sonography and computerized tomography (CT) scan of an accessory spleen often reveal a small round or ovoid hypoechoic mass with similar echogenicity below the splenic hilum [6]. An accessory spleen may have homogenous appearance, a normal vascular branching pattern, low resistance flow, and similar RI to that of the native spleen [3]. In typical cases, accessory spleen can be diagnosed sonographically by demonstrating blood supplies from the splenic vessels [7]. Scintigraphy, splenic angiography, or magnetic resonance (MR) imaging may be helpful in the diagnosis of atypical cases [8]. The presence of an accessory spleen is generally asymptomatic and of no clinical importance. Surgical removal can be performed in patients with acute abdomen caused by torsion or rupture of the accessory spleen. Accessory spleen plays an important role in thrombocytopenia, especially in idiopathic thrombocytopenic purpura Fig. 1. Abdominal ultrasound shows a large, well-defined, heteroechoic, (ITP). ITP is an immune disorder mediated by autoantibodies solid mass at the right of the uterus. to platelet membrane antigens, in which platelet destruction by the reticuloendothelial system occurs, largely in the spleen [9]. Patients with chronic ITP should be investigated for the was completely excised from the vascular pedicle. The mass presence of accessory spleen. This abnormality may be found weighed 174 g and the histopathologic study confirmed an in about 10% of patients with recurrent ITP after primary accessory spleen with congestive splenomegaly. The patient splenectomy and is suggested by the absence of Howell-Jolly recovered well and was discharged on the third postoperative bodies in the peripheral blood smear [9, 10]. Facon et al day. The follow-up platelet count at 9 months had increased reported that accessory splenectomy was beneficial in cases to 374,000/µL. of severe thrombocytopenia after splenectomy and might be delayed until worsening of the clinical course in patients with moderate thrombocytopenia with a small accessory spleen [10]. In our patient, accessory splenectomy resulted in com- iscussion plete remission of thrombocytopenia and lower abdominal D pain. Why the accessory spleen of our patient became so large Accessory spleen is the result of failure of fusion of separate is unclear. Holloway et al described a case of portal hyperten- masses originating from the left side of the dorsal mesogastrium. sion resulting in massive enlargement of an accessory spleen [11]. Marked engorgement of the vessels may result from intermittent torsion or compression of the long vascular pedicle, which may lead to venous congestion and then enlargement of the accessory spleen. This phenomenon may explain how accessory splenomegaly and lower abdominal pain developed in our patient. Most solid pelvic masses in women are of uterine or ovarian origin. Rarely, solid pelvic tumors are caused by conditions including metastasis, tubal carcinoma, lymphadenopathy, or ectopic pelvic kidney. Ovarian echogenic cysts and uterine leiomyomas can be differenti- ated from other ovarian solid tumors because of the presence of main blood flows within these tumors, instead of at the periphery [12]. Fast-growing tumors contain many newly formed vessels and often have low resistant blood flow. Timor-Tritsch et al reported that the combination of a high morphologic score and a low RI on color Doppler sonography predicted all of a series of 14 ovarian malignancies. It is worth noting that benign ovarian solid masses such as fibromas and thecomas in their study had high scores but high RIs [13]. Generally, the diagnosis of ovarian cancer requires an Fig. 2. Spectral Doppler ultrasound shows that the mass has a low exploratory laparotomy; abdominal and pelvic CT or MR resistance index of 0.39 and a low pulsatility index of 0.48. imaging scans are of no value for patients with a definite

566 J Formos Med Assoc 2001 • Vol 100 • No 8 Accessory Spleen Mimicking Adnexal Malignancy pelvic mass [14]. About one-third of ovarian tumors in 5. Denehy T, McGrath EW, Breen JL: Splenic torsion and rupture in children and adolescents are malignancies, including germ pregnancy. Obstet Gynecol Surv 1988;43:123–31. cell tumors, sex cord-stromal tumors, and epithelial carcino- 6. Coote JM, Eyers PS, Walker A, et al: Intra-abdominal bleeding mas [15], with the CA-125 concentration elevated in only caused by spontaneous rupture of an accessory spleen: the CT findings. Abdom Imaging 1998;23:194–5. 30% to 50% of stage I ovarian carcinomas [12]. Besides, some 7. Subramanyam BR, Balthazar EJ, Horii SC: Sonography of the germ cell tumors such as immature teratomas and pure accessory spleen. AJR 1984;143:47–9. germinomas do not secrete tumor markers [14]. Therefore, 8. Seo T, Ito T, Watanabe Y, et al: Torsion of an accessory spleen ovarian malignancy, such as germ cell tumor or sex cord- presenting as an acute abdomen with an inflammatory mass. stromal tumor, was suspected preoperatively in our patient. Pediatr Radiol 1994;24:532–4. In conclusion, an accessory spleen should be included 9. George JN, Ed-Harake MA, Raskob GE: Chronic idiopathic in the differential diagnosis of a solid adnexal tumor with thrombocytopenic purpura. N Engl J Med 1994;331:1207–11. low resistant blood flow, especially in patients with 10. Facon T, Caulier MT, Fenaux P, et al: Accessory spleen in thrombocytopenia. recurrent chronic immune thrombocytopenic purpura. Am J Hematol 1992;41:184–9. 11. Holloway BJ, Pei L, Pfister R: Case report: portal hypertension causing massive enlargement of an accessory spleen – a rare cause of splenic pseudotumour. Clin Radiol 1997;52:882–4. eferences 12. Fleischer AC, Manning FA, Jeanty P, et al: Sonography in R Obstetrics and Gynecology: Principles and Practice. 5th ed. Stamford, CT: Appleton & Lange,1996:791–813. 1. Halpert B, Gyorkey F: Lesions observed in accessory spleens of 13. Timor-Tritsch IE, Lerner JP, Monteagudo A, et al: Transvaginal 311 patients. Am J Clin Pathol 1959;32:165–8. ultrasonographic characterization of ovarian masses by means 2. Azar GB, Awwad JT, Mufarrij IK: Accessory spleen presenting as of color flow directed Doppler measurements and a morpho- adnexal mass. Acta Obstet Gynecol Scand 1993;72:587–8. logic scoring system. Am J Obstet Gynecol 1993;168:909–13. 3. Vural M, Kacar S, Kosar U, et al: Symptomatic accessory spleen 14. Berek JS, Fu YS, Hacker NF: Ovarian cancer. In: Berek JS, Adashi in the pelvis: sonographic finding. J Clin Ultrasound 1999;27: EY, Hillard PA, eds. Novak’s Gynecology. 12th ed. , MD: 534–6. Williams & Wilkins, 1996:1155–230. 4. Babcock TL, Cocker DD, Haynes JL, et al: Infarction of an 15. Van Winter JT, Simmons PS, Podratz KC: Surgically treated accessory spleen causing an acute abdomen. Am J Surg 1974; adnexal masses in infancy, childhood and adolescence. Am J 127:336–7. Obstet Gynecol 1994;170:1780–9.

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