[212] Primary Breast Malignant Fibrous Histiocytoma (MFH): A Clinicopathologic Review of 19 Cases with Two New Variants

PH Hartel, G Bratthauer, JV Hartel, T Vinh, JC Fanburg-Smith. Davis Memorial Hospital, Elkins, WV; AFIP, Washington, DC; Covenant Medical Center, Waterloo, IA

Background: Primary breast MFH is rare and can pose a diagnostic challenge. We reviewed our experience with this entity.
Design: Cases coded as “MFH,” “myxofibrosarcoma” or “pleomorphic sarcoma NOS” were culled from our registries. Cases meeting WHO morphologic and immunohistiochemical criteria for MFH variants were included; FNCLCC grading scheme was applied. Recorded histologic features included inflammation, vascular pattern, stromal appearance, mitotic activity, necrosis, cell, nuclear and nucleolar morphology, and growth pattern. Clinical and follow-up data were obtained. Only primary cases in breast were included. Eight cases were excluded due to better diagnosis as another tumor or insufficient material.
Results: Nineteen patients with primary breast MFH included one male and 15 females, ranging in age from 15 to 86 years (mean, 59). Tumor size ranged from 1.3 cm to 15 cm (mean, 6.3). Most patients received wide local excision with or without adjuvant therapy. Five patients with an older mean age (70 years) had distant metastases and died of disease within from one to 19 months (mean, 6). Cases were MFH storiform/pleomorphic (10/19) and giant-cell (1/19) subtypes and myxofibrosarcoma (6/19). Other histologic features were entrapped breast epithelium (14/19), hemangiopericytoma-like vessels (5/19), and prominent eosinophilic nucleoli (5/19). Unique lymphocyte-rich and pleomorphic hyalinizing angiectatic tumor (PHAT)-like variations were observed. Lymphocyte-rich variant showed pleomorphic spindle cells and prominent intratumoral lymphocytes, many in aggregate. PHAT-like variant showed large ectatic vessels, hemosiderin, pleomorophism, but with brisk mitotic activity. Cases were negative for pancytokeratins, S100, CD34 and desmin.
Conclusions: Primary breast MFH mostly affects middle-aged women. Distant metastases and older patient age appear to be associated with poor outcome. Storiform/pleomorphic and myxofibrosarcoma are the most common subtypes. Entrapped breast epithelium should not be misinterpreted as the epithelial component of a biphasic tumor. We present novel lymphocyte-rich and PHAT-like tumors. Careful attention to histology and immunohistochemistry of primary breast MFH can prevent misdiagnosis.
Category: Breast

Monday, March 22, 2010 1:00 PM

Poster Session II # 39, Monday Afternoon


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