title: Pleomorphic hyalinizing angiectatic tumor of soft parts: a case report and literature review.
abstract: Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare, recently recognized neoplasm occurring predominantly in the subcutaneous tissue of the lower limbs of adults. We report a case of PHAT in an 83-year-old woman who presented with a 5.0 x 5.0 x 2.0 cm mass in the soft part of her left thigh. Histologically, the tumor was well circumscribed by a thin fibrous capsule and predominantly composed of fusiform cells with eosinophilic cytoplasm and round-to-oval or pleomorphic nuclei. The tumor cells resembled those of malignant fibrous histiocytoma, but differed from them by less prominent mitotic figures. Immunohistochemically, the tumor cells were diffusely and strongly positive for CD34; partially positive for vimentin and CD99 (MIC-2); and negative for epithelial and non-epithelial markers. Ultrastructurally, the tumor cells had pleomorphic cytoplasm and nucleus. Intermediate-sized cytoplasmic filaments were observed in a few tumor cells, but neurosecretory-type granule-like intracytoplasmic organelles were not seen. These findings suggest that this tumor is derived from stromal fibroblast, such as solitary fibrous tumors or giant cell angiofibroma.
authors.affiliation: Division of Pathology, Second Hospital of Nippon Medical School, Kawasaki, Japan. koshi@nms.ac.jp
authors.forename: Koshi
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Taiich
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D000071443:12E7 Antigen; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000378:metabolism; D018952:Antigens, CD34 / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002467:Cell Nucleus / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D005260:Female; D018219:Histiocytoma, Benign Fibrous / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D006818:Hyalin / Q000378:metabolism; D007150:Immunohistochemistry; D009442:Neurilemmoma / Q000378:metabolism / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000378:metabolism / Q000473:pathology*; D013848:Thigh / Q000473:pathology; D016896:Treatment Outcome; D014746:Vimentin / Q000378:metabolism
chemical_list: D000071443:12E7 Antigen; D015703:Antigens, CD; D018952:Antigens, CD34; D014408:Biomarkers, Tumor; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D014746:Vimentin