Gallbladder sarcoma: a clinicopathological study of seven cases from the UK and Austria with emphasis on morphological subtypes.

BACKGROUND: Primary sarcoma of the gallbladder (PGBS) is rare, with only 40 cases reported in the literature. Most of these have been diagnosed as leiomyosarcoma. We aimed to evaluate the histological features of a case series of this rare tumor and correlate these with clinical features. DESIGN: Cases recorded as "gallbladder sarcoma" from different institutes were reviewed and the clinicopathological features of these cases were recorded. Only primary gallbladder wall mesenchymal tumors were included. Epithelial tumors, mixed tumors (carcinosarcoma or sarcomatoid carcinoma), and tumors extending into the gallbladder from the abdomen or sarcoma with other known primaries were specifically excluded. RESULT: PGBS occurred in one male and six females with a median age of 70 (range 64-82) years. Patients presented with acute or chronic cholecystitis, abdominal pain, weight loss, and pruritus. They were generally found to have elevated alkaline phosphatase and bilirubin, and leukocytosis. Tumors ranged from 1.1 to 4 cm with a median size of 3 cm. Most PGBS arose in the body but one arose in the fundus. All tumors were associated with ulcerated mucosa. Based on morphological and immunohistochemical features of the PGBS, there were three myxofibrosarcomas (malignant fibrous histiocytoma, MFH, storiform pleomorphic), one leiomyosarcoma (LMS), one angiosarcoma (AS), and two liposarcomas (LS). All patients received cholecystectomy and three received adjuvant chemotherapy. Follow-up revealed that six patients died of the disease 6 weeks to 2 years after diagnosis and one died of unrelated causes. CONCLUSION: PGBS are rare and mainly occur in the gallbladder body in middle-aged females. They generally present with acute cholecystitis and have a very poor prognosis. A variety of sarcoma types are found with MFH being the predominant variant.