Primary hemangiopericytoma of the liver.
Article Type: Case study
Subject: CT imaging (Usage)
CT imaging (Health aspects)
Hemangioendothelioma (Risk factors)
Hemangioendothelioma (Diagnosis)
Hemangioendothelioma (Care and treatment)
Hemangioendothelioma (Patient outcomes)
Hemangioendothelioma (Case studies)
Authors: Oppermann, Timothy
Sell, Harry W., Jr.
Miller, Margaret A.
Stahlfeld, Kurt R.
Pub Date: 04/01/2010
Publication: Name: Applied Radiology Publisher: Anderson Publishing Ltd. Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2010 Anderson Publishing Ltd. ISSN: 0160-9963
Issue: Date: April, 2010 Source Volume: 39 Source Issue: 4
Geographic: Geographic Scope: United States Geographic Code: 1USA United States
Accession Number: 231310681
Full Text: CASE SUMMARY

A 59-year-old man presented to his primary care physician with a 10 lb weight loss and a slowly enlarging abdominal mass. He denied any gastrointestinal symptoms, cirrhosis, hepatitis, overseas travel or exposure to toxins. His past medical history was significant for hypertension and anemia. The only notable finding on physical exam was a large, right upper quadrant abdominal mass. Computed tomography (CT, Figure 1) and magnetic resonance imaging (MRI, Figure 2) were performed. Carcinoembryonic antigen (CEA), cancer antigen (CA 199) and alpha-fetoprotein levels were normal.

IMAGING FINDINGS

Large heterogeneous lesions of the liver are rarely resectable for cure. However, the CT findings demonstrated no invasion of adjacent structures, no significant adenopathy and no evidence of malignancy. Additionally, the enhancement characteristics on MRI were not classic for hepatocellular carcinoma. Although the possibility of cure and the diagnosis were in doubt, the patient underwent diagnostic laparoscopy, laparotomy and left lateral segmentectomy (seg. 2 and 3). Pathology revealed a 21 cm hemangiopericytoma. Resection margins and lymph nodes were negative for tumor. The mass stained positive for CD99 and Bcl2, weakly positive for CD34 and smooth muscle actin, and negative for CD31 and EMA. This pattern is consistent with a hemangiopericytoma (solitary fibrous tumor.)

DIAGNOSIS

Primary hemangiopericytoma of the liver

DISCUSSION

Hemangiopericytoma, first described and named by Stout and Murray in 1942, (1) is an uncommon spindle-cell tumor that pathologically displays a thin-walled vascular branching pattern. These tumors are derived from mesenchymal cells, can be benign or malignant, and occur more commonly in the lower extremities, but they have been described in the liver, pelvis and retroperitoneum. In an attempt to standardize nomenclature, some pathologists use the CD34, CD99, epithelial membrane antigen, GLC2, and smooth muscle actin stains to identify a subset of these tumors as solitary fibrous tumors.

Only 23 reported cases of primary liver hemangiopericytoma have been reported in the English literature. (2) Both sexes in their sixth decade are affected equally. Clinical features include abdominal fullness and mass, weight loss, vomiting, diarrhea, fatigue and hypoglycemia. (3) Information about the radiographic characteristics of hemangiopericytomas is scant. Fuksbrumer et al. described heterogenous enhancement on MRI and CT due to differential enhancement of the admixed cellular and collagenous components. (4) Other anecdotal cases report areas of necrosis and calcification; these were not noted in our patient.

Although imaging features may suggest the diagnosis of a primary hemangiopericytoma of the liver, other benign or malignant hepatic tumors such as sarcoma, leiomyoma and inflammatory pseudotumor of the liver may have similar features. (4) As resection of these tumors may result in longterm survival, one should avoid the misdiagnosis and nihilism associated with hepatocellular carcinoma. Following primary excision, there is little role for radiation or chemotherapy.

REFERENCES

(1.) Stout AP, Murray MR. Hemangiopericytoma: A vascular tumor featuring Zimmermann's pericytes. Ann Surg. 1942;116:26-33.

(2.) Ji Y, Fan J, Xu Y, et al. Solitary fibrous tumor of the liver. Hepatobiliary Pancreat Dis Int. 2006;5:151-153.

(3.) Moran CA, Ishak KG, Goodman ZD. Solitary fibrous tumor of the liver; A clinicopathologic and immunohistochemical study of nine cases. Ann Diagn Pathol. 1998;2:19-24.

(4.) Fuksbrumer MS, Klimstra D, Panicek DM. Solitary fibrous tumor of the liver: Imaging findings. AJR Am J Roentgenol. 2000;175:1683-1687.

Timothy Oppermann, MD, Harry W. Sell, Jr., MD, FACS, Margaret A. Miller, MD, and Kurt R. Stahlfeld, MD, FACS

Prepared by Timothy Oppermann, MD, The Methodist Hospital, Houston, TX, and Harry W. Sell, Jr., MD, FACS, Margaret A. Miller, MD, and Kurt R. Stahlfeld, MD, FACS, UPMC Mercy Hospital, Pittsburgh, PA.
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