title: Pleomorphic hyalinizing angiectatic tumor with a sarcomatous component recurring as high-grade myxofibrosarcoma.
abstract: Pleomorphic hyalinizing angiectatic tumor (PHAT) of the soft tissue is a rare distinctive tumor listed as a benign neoplasm in the new World Health Organization classification. It may recur and most reported recurrent tumors retained the typical morphological appearance of PHAT; rare tumors recurred with the appearance of a sarcoma. Reported herein is an additional example of recurrent PHAT, but in contrast to the previously described cases the present tumor morphologically qualified as a sarcoma from the very beginning; it recurred as a high-grade myxofibrosarcoma. A 76-year-old woman presented with a solitary subcutaneous tumor in the axilla that was surgically removed. Seven months later, the patient experienced a local recurrence. Microscopically, the typical features of PHAT were identified in the initial lesion, namely hyalinized, fibrin-containing vessels and pleomorphic stromal cells; there were areas of hemorrhage and necrosis. Additionally, peripherally located areas of the tumor manifested highly pleomorphic cells with frequent atypical mitoses, producing a sarcomatous appearance. The mitotic index in the sarcomatous part was 1/10 high-power fields (HPF). Hyalinized, fibrin-containing vessels were absent in these sarcomatous areas, and the stroma was myxoid. The recurrent lesion was composed of large highly pleomorphic oval, round, spindled or bizarre cells with a high mitotic rate, ranging from 3/10 HPF to 7/10 HPF. The neoplastic cells were arranged haphazardly in a myxoid matrix. Hyalinized, fibrin-containing vessels typical for PHAT were absent. PHAT may be more aggressive than previously thought, and PHAT may encompass a morphological spectrum of the lesion ranging from benign to malignant.
authors.affiliation: Sikl's Department of Pathology, Charles University, Medical Faculty Hospital, Pilsen, Czech Republic. kazakov@medima.cz
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Kazakov
authors.forename: Michal
authors.initials: M
authors.lastname: Pavlovsky
authors.forename: Petr
authors.initials: P
authors.lastname: Mukensnabl
authors.forename: Michal
authors.initials: M
authors.lastname: Michal
mesh_terms: D000368:Aged; D018223:Dermatofibrosarcoma / Q000473:pathology*; D005260:Female; D005337:Fibrin / Q000378:metabolism; D006801:Humans; D006818:Hyalin / Q000378:metabolism; D009336:Necrosis; D009364:Neoplasm Recurrence, Local; D012509:Sarcoma / Q000378:metabolism / Q000473:pathology; D012867:Skin / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000473:pathology
chemical_list: D005337:Fibrin