Pleomorphic hyalinizing angiectatic tumor of soft parts: a case report with review of the literature

Pleomorphic hyalinising angiectatic tumour (PHAT) is a very rare, locally aggressive neoplasm characterized by spindle-shaped and pleomorphic cells with ectatic hyalinised-walled blood vessels. The World Health Organization classifies this entity as a “tumour of uncertain differentiation.” PHAT most commonly occurs in the superficial subcutaneous tissues of the lower extremities, particularly around the ankle and foot; however, other locations have also been reported. Occurrence in deep soft tissues (retroperitoneum, perivisceral regions) and in the cervical area is exceedingly rare. The tumour typically grows slowly and manifests as a long-standing, painless mass, often mimicking hematoma or, less frequently, lipoma. Its aetiology and exact pathogenesis remain unclear. Local recurrence occurs in 30–50% of cases, though repeated surgical excision generally provides effective control. We present the case of a 56-year-old male patient with a pleomorphic hyalinising angiectatic tumour of the right paraumbilical region. In addition, we review the literature to outline the epidemiology, morphology, and prognostic features of this rare entity, with particular emphasis on the challenges of differential diagnosis.