Giant cell fibroblastoma: an entity or a reactive phenomenon?

The histological and immunohistochemical features of four tumors displaying the characteristic pattern of Giant Cell Fibroblastoma (GCF) are presented. Three of them were found in association with classical and/or myxoid dermatofibrosarcoma protuberans, while the fourth tumor was a retroperitoneal malignant hemangiopericytoma where foci with features of GCF were found. Typical sinusoidal spaces and the bizarre mononuclear and multinucleated cells in close association to blood vessels presenting a wide spectrum of lesions of their walls are also described.

Intraosseous lipoma. A report of three cases.

Intraosseous lipomas are considered to be among the rarest primary benign bone tumors. Lipoma developing in bone frequently presents evolutional changes, which in association with the lack of clinical information and the radiographic appearance of the bone lesion could be the main reasons for misinterpretation of the histological picture. We present three cases of intraosseous lipoma which developed in male patients aged 23, 34 and 35 years, involving the tibia (n = 2) and calcaneus (n = 1).

Primary vascular bone sarcomas. A clinicopathological and immunohistochemical study of two cases.

Two cases of primary vascular bone sarcomas are reported. The first case presented a rather slow clinical course and a non-aggressive histological picture and was classified as hemangioendothelioma. The second was a frankly malignant tumor, already metastatic at the time of diagnosis, which was classified as angiosarcoma.