DrCycloPath posts PHAT with hemosiderin
- Pathologist Charles Herndon, who posts as DrCycloPath, shared a pathology teaching case of pleomorphic hyalinizing angiectatic tumor with hemosiderin-laden spindle cells. - The teaching point was the mismatch between striking nuclear pleomorphism and sparse mitotic activity, a pattern that can mimic sarcoma on first glance. - PHAT is a rare soft-tissue tumor with local recurrence risk but no established metastatic potential. (pathologyoutlines.com)
Pleomorphic hyalinizing angiectatic tumor is a rare soft-tissue tumor that can look far more aggressive under the microscope than it usually behaves in patients. (pathologyoutlines.com) (dermnetnz.org) Charles Herndon, the pathology educator who posts as DrCycloPath, used a recent case to show that PHAT can contain bizarre-looking spindle cells packed with hemosiderin, an iron pigment left behind after old bleeding. (threadreaderapp.com) (dermnetnz.org) Under the microscope, PHAT is defined by widened, damaged blood vessels with glassy hyaline change, pleomorphic tumor cells, and mitotic figures that are usually rare. (pathologyoutlines.com) (dermnetnz.org) That combination creates the diagnostic trap: the nuclei can look high-grade, but the low mitotic activity and lack of metastatic behavior separate PHAT from many true sarcomas. (pathologyoutlines.com) (dermnetnz.org) The World Health Organization’s 2020 classification places PHAT among neoplasms of uncertain behavior rather than straightforward benign lesions or conventional metastatic sarcomas. (mdpi.com) (pubmed.ncbi.nlm.nih.gov) Published reviews say roughly 100 cases had been reported internationally by 2021, with most tumors arising in superficial soft tissue of the distal leg, ankle, or foot. (mdpi.com) (pathologyoutlines.com) Pathologists also watch for overlap with hemosiderotic fibrolipomatous tumor and myxoinflammatory fibroblastic sarcoma, two lesions that may sit on a related morphologic spectrum. (mdpi.com) (pathologyoutlines.com) Treatment guidance is surgical: complete excision with negative margins, because PHAT is locally aggressive and can recur even though metastasis has not been established. (pathologyoutlines.com) (dermnetnz.org) The practical lesson from the case is simple: in PHAT, dramatic atypia is not the whole story, and counting mitoses still changes the diagnosis. (pathologyoutlines.com) (dermnetnz.org)
