Pleomorphic hyalinizing angiectatic tumor with a sarcomatous component recurring as high-grade myxofibrosarcoma
Article first published online: 16 APR 2007
Volume 57, Issue 5, pages 281–284, May 2007
How to Cite
Kazakov, D. V., Pavlovsky, M., Mukensnabl, P. and Michal, M. (2007), Pleomorphic hyalinizing angiectatic tumor with a sarcomatous component recurring as high-grade myxofibrosarcoma. Pathology International, 57: 281–284. doi: 10.1111/j.1440-1827.2007.02094.x
- Issue published online: 16 APR 2007
- Article first published online: 16 APR 2007
- Received 2 October 2006. Accepted for publication 15 December 2006.
- myxoid malignant fibrous histiocytoma;
- pleomorphic hyalinizing angiectatic tumor;
- undifferentiated sarcoma
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.