Benign Fibrohistiocytoma (Xanthomatous Variant) of the Acromion

Abstract

A number of fibrous lesions involving bone display almost identical histologic appearances yet may represent either reactive or neoplastic conditions, resulting in a confusing nomenclature and possible diagnostic confusion. We report the case of a young man with no significant previous medical history who presented with a painful lesion in the left shoulder, which consisted almost entirely of xanthomatous material. We discuss the possible differential diagnosis of this lesion and why benign fibrous histiocytoma is the preferred terminology for this lesion. To our knowledge, this is the first reported case of a benign fibrous histiocytoma involving the acromion in an adult.

Benign fibrous histiocytoma, case report

“…It is a tumor of fibroblasts and multinucleated cells resembling histiocytes (dendritic cells of the dermis), described in the dermis with extension to subcutaneous tissue, but respecting epidermis. Sometimes full of fat cells, so too have described as xanthoma or fibroxanthoma [6].…”

“…The differential diagnosis is storiform pattern with dermatofibrosarcoma protuberans (DFSP) (major cellular component, not epsonjosas cells), malignant fibrous histiocytoma (infiltrative, marked pleomorphism and mitotic activity) and hemangiopericytoma. atypical fibroxanthoma, Kaposi's sarcoma (vascular tumor with extravasation of red blood cells), leiomyoma or leiomyosarcoma (muscle fibers), myofibroblastic sarcoma (infiltrative, desmin positive), and Rosai-Dorman disease (CD68 positive histiocytes, no storiform) [6,8].…”

“…Primarily it manifests as primary skin lesions in sun-exposed areas and bones in the lower extremities, face and neck, and in some rare cases abdominal wall. The skin lesion is usually a papule, solitary and slow growth; that the onset is asymptomatic but then may present with pain, which progresses to chronic even for years [6][7][8][9][10][11].…”