Pleomorphic hyalinizing angiectatic tumor.

Authors present an additional case report of pleomorphic hyalinizing angiectatic tumor (PHAT), only recently recognized entity amongst the soft tissue tumors. 63-year-old man underwent surgery for subcutaneous tumor growing on the forearm. Grossly, ovoid well demarcated tumor 4.0 x 3.5 x 2.5 cm was removed. Histologically, hypovascular areas of spindle-cells arranged in sheets and fascicles resembling spindle-cell sarcoma and areas rich on ectatic vessels with fibrin deposits or thickened hyalinized walls were present. Some cells contained intranuclear cytoplasmatic inclusions, lobulated nuclei with or without prominent nucleoli or multiple nuclei. Mitoses were less than 1 per 30 HPF, Ki-67 nuclear positivity was observed in 2.6% of tumor cells. Immunohistochemically, cells were positive with vimentin, but negative for CD34, S100, desmin, smooth-muscle actin, EMA, VWF, CD99, bcl-2 and cytokeratins. The patient did well, without recurrent tumor after 13 months follow-up. Spectrum of tumors including solitary fibrous tumor, giant-cell angiofibroma, neurilemmoma, malignant fibrous histiocytoma and acral myxoinflammatory tumor with atypical bizarre giant cells is discussed in differential diagnosis.