Solitary Fibrous Liver Tumor: Is Surgical Approach the Best Option?

Paula Novais1, Carlos Robles-Medranda1, Vera Lucia Pannain2, Daniel Barbosa3, Beatriz Biccas1, Homero Fogaça1

1) Gastroenterology Division; 2) Department of Pathology; 3) Surgery Division, Clementino Fraga Filho Hospital, Federal University of Rio de Janeiro, Brazil

Abstract can be preliminarily deduced from the clinical history as well as from imaging examination. However it can only be Solitary fibrous tumor of the liver is a rare tumor, where confirmed by histopathological and immunohistochemical the evolution, malignant potential, and invasive growth have studies. The recommended treatment is surgical resection [5], not been well defined. Although most cases are benign, there mainly because of the intrinsic potential of malignancy that is no strict correlation between histological findings and may be misdiagnosed in needle-sample biopsies [6]. biological behavior, and follow-up surveillance is necessary. We report the case of a large hepatic SFT that initially We present the case of a large solitary hepatic fibrous tumor appeared to be an unresectable mass, and we describe the and its clinical outcome after a 4-year follow-up. Additional clinical course with a 4-year follow-up. We also discuss therapeutic options are also reviewed. The surgical resection the therapeutic options in cases where the possibility of is a plausible therapy in large solitary fibrous tumors of malignancy is present. the liver, although liver transplantation may be discussed when the tumor is considered unresectable. However, such Case report aggressive approaches are questionable in asymptomatic patients due to the natural history of this tumor, which is A 34-year old female, with no past medical history, was not well known, and the risk of complications. initially admitted to our hospital in May 2001 with abdominal pain and an increase of abdominal circumference. There was Keywords no previous history of alcohol, drugs or medication intake. Upon physical examination, the liver was 11 cm below the Solitary fibrous tumor – liver tumor – liver transplantation lower edge of the ribs. There was no ascites, edema, hepatic – CT scan – MRI failure signs, or cirrhosis stigmata. Laboratory tests including alpha fetoprotein were within the normal range. Serum viral Introduction markers were all negative and no esophageal varices were Solitary fibrous tumor (SFT) is a mesenchymal neoplasia, found upon an upper endoscopy study. which frequently occurs in pleura. It has also been described Abdominal ultrasound with Doppler fluxometry revealed in other sites including the liver (mainly in the right lobe), a large heterogeneous hypoechoic mass of 20 x 16 cm limited orbits, superior respiratory tract, abdomen, breast and soft to the right hepatic lobe with no portal, hepatic or inferior tissue [1]. cava vein involvement. Helical computer tomography (CT- The hepatic location is extremely rare, with only scan) demonstrated a large heterogeneous circumscribed approximately 30 cases described in the literature [2-4]. mass in the right hepatic lobe and left medial segment with The symptoms are commonly related to the abdominal contrast enhancement in arterial, portal and equilibrium mass, when the tumor reaches a large size. The diagnosis phases (Fig. 1). Laboratory and radiological findings were unable to exclude the possibility of fibrolamellar hepatocellular carcinoma. Received: 24.11.2008 Accepted: 03.12.2008 Surgical resection was tried without success because J Gastrointestin Liver Dis the tumor was adherent to the right and the middle hepatic March 2010 Vol.19 No 1, 81-84 Address for correspondence: Paula Novais vein; the procedure was considered technically difficult. Clementino Fraga Filho Hospital The surgical team at that moment found the tumor to be Federal University of Rio de Janeiro unresectable. A right hepatic arterial ligature was performed Rodolpho Paulo Rocco av to decrease the tumor size. The biopsy of the tumor showed Rio de Janeiro, Brazil. Email: [email protected] lesions associated with SFT: a few neoplastic spindle cells 82 Novais et al

Fig 1. CT scan of solitary fibrous tumor. A: CT scan Fig 2. Histological examination: A. Collagen without contrast. B: Contrast enhancement in arterial bundles with few spindle cells (H-E x 200); B. CD34 phase, large heterogeneous circumscribed mass in immunostaining showing diffuse reactivity. the right hepatic lobe and left medial segment. with uniform and elongated nuclei without atypia and separated by abundant thick collagen bands with capillaries (Fig. 2A). The clinical course and the tumor size did not change in the following 11 months, after which another tumor biopsy was performed and showed the same findings as before. The immunohistochemistry study revealed CD34 (Fig. 2B) and vimentin antibody positivity in the neoplastic cells, confirming SFT. There were no other therapeutic options and, due to the large tumor size with malignant potential, the patient was Fig 3. MRI in T1 with hypointense areas, suggesting listed for liver transplantation. Two years later, a CT-scan cystic degeneration and necrosis in the SFT. and magnetic resonance imaging (MRI) did not show any change in the tumor size, although small multiple hypodense The patient was discharged 40 days after surgery in areas were seen in the MRI, suggesting cystic degeneration excellent clinical condition. and necrosis (Fig. 3). The tumor weight was 3,700 g and size 25 x 23 x 13cm In the following year, as the patient was clinically (Fig. 4). The tumor was encapsulated and had a gray-white stable, without alteration in her liver function, and as the surface with whorled and myxoid areas. Microscopic risk of malignant transformation is not well defined in the findings showed acellular areas with hyaline collagen bands literature, another attempt of surgical resection was made and a few spindle cells with fusiform nuclei and minimal prior to liver transplantation. The remnant liver volume cytoplasm. No cellular atypia and no mitotic activity were at CT-scan was estimated to be 32%, and finally a right found. The cells were immunoreactive for vimentin and hepatic lobectomy including segments IV a, b; V; VI; VII CD34, and negative for cytokeratin, S-100 protein, and and VII was performed successfully after vascular exclusion CD-117 antibodies. of the liver. The postoperative course was complicated by Currently, two years after surgery, the patient is an infected hematoma, which was controlled by antibiotic asymptomatic and has normal liver function and no signs therapy and intensive care support for 21 days. of local or distant recurrence. Solitary fibrous liver tumor 83

physician to the possibility of atypical features or malignant transformation [7, 12], and biopsy may not identify a malignant component in the sample taken. Surgical resection is the recommended treatment [6], although high morbidity and mortality have been described in large lesions which require extensive resections [5]. There are no data about liver transplantation in patients with SFT. However, unresectable rare non-hepatocellular or bile duct tumors that arise within the hepatic parenchyma are a formal indication of liver transplantation [13]. Therefore, this approach was proposed to our patient, and could be considered as a therapeutic option. In these cases, when patients are in excellent condition, living donor liver transplantation could be indicated. In our case, it was initially found that the lesion was unresectable, so ligature of the right hepatic artery was attempted in order to reduce the tumor size. The ligature of the hepatic artery, used in other liver tumors, arises as an option to generate hypotrophy of the tumor, allowing a better resection [14]. However, this approach did not succeed and probably it is not a good option for SFT. As the patient remained stable for 4 years with a normal hepatic function and without additional tumor growth, a new resection was attempted to avoid liver transplantation. The resection was successful and the lesion was completely removed. Fig 4. Macroscopic view of the solitary fibrous tumor after surgery: 25x23x13 cm in size. There was a good surgical response and no malignancy was found on pathologic examination. However, a life threatening surgical complication occurred as a result of Discussion such extensive surgery. The question remains whether such The hepatic SFT is extremely uncommon [8], with aggressive treatments are worthwhile in asymptomatic a varied presentation. The patient may be asymptomatic patients with excellent liver condition where the real risk or present with abdominal pain, increased abdominal of malignancy is unknown. Due to the rarity of this tumor, volume, hypoglycemia [9], or alterations of liver tests the prognosis has not been well defined [15]. and compression of biliary ducts leading to cholestasis [7]. In the differential diagnosis it is necessary to exclude Conclusion the possibility of hepatocellular carcinoma, sarcoma, Surgical resection is a plausible therapeutic option in large leiomyoma, and inflammatory myofibroblastic tumor. The solitary fibrous tumors of the liver and transplantation can be radiological findings are unspecific, and cannot distinguish considered when the tumor is non-resectable. However, such between benign and malignant tumors [1, 7]. The lesion is aggressive approaches are questionable in asymptomatic usually a solitary mass, highly vascular, well circumscribed, patients due to the natural history of this tumor, which is not encapsulated, and showing heterogeneous enhancement (due well known, and the risk of other complications. to the varied density from the collagen component) in CT and MRI images [7]. Histopathological and immunohistochemical References studies are necessary for correct diagnosis. The CD34 antibody is a marker for SFT diagnosis, although it is not 1. Neeff H, Obermaier R, Technau-Ihling K, et al. Solitary fibrous specific [10] and can also be positive in angiosarcomas and tumour of the liver: case report and review of the literature. gastrointestinal stromal tumors [7]. However, the clinical Langenbecks Arch Surg 2004; 389: 293-298. course and more specific immunostainings as the anti-CD31 2. Chithriki M, Jaibaji M, Vandermolen R. Solitary fibrous tumor of in cases of angiosarcomas, and the C-kit stain CD117 for the liver with presenting symptoms of hypoglycemic coma. Am Surg GIST are useful and offer a definitive diagnosis. 2004; 70: 291-293. 3. Saint-Marc O, Pozzo A, Causse X, Heitzmann A, Debillon G. Tumeur The main concern in such cases is that SFT can develop fibreuse solitaire du foie: caractéristiques cliniques, radiologiques et a malignant transformation [11]. It is possible that malignant anatomo-patologiques. Gastroenterol Clin Biol 2002; 26: 171-173. and benign areas are present in the same lesion. The 4. Vennarecci G, Ettorre GM, Giovannelli L, et al. Solitary fibrous tumor hypercellularity, nuclear atypia, necrosis and high mitotic of the liver. J Hepatobiliary Pancreat Surg 2005; 12: 341-344. activity are considered criteria for malignancy [1, 7]. Larger 5. Moran CA, Ishak KG, Goodman ZD. Solitary fibrous tumor of the tumors (> 10 cm) are correlated with lower disease-free liver: a clinicopathologic and immunohistochemical study of nine metastasis survival [12]. Necrotic areas should alert the cases. Ann Diagn Pathol 1998; 2: 19-24. 84 Novais et al

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