UHGPS is a sarcoma of debated nosology affecting adults, with rare cases reported in children.
UHGPS are rare in children and frequently located in the head. A more favorable outcome is associated with superficial location. Foci of epithelioid cell may portend an aggressive behavior.
Differential diagnosis
Dedifferentiated liposarcoma (DDL), occurring in up to 10% of well differentiated liposarcoma cases, has similar histologic features to that of undifferentiated high-grade pleomorphic sarcoma (UHGPS) ; the former develops in a background of atypical lipomatous tumors/well differentiated liposarcoma, whereas the latter shows no specific line of differentiation. The retroperitoneum and thigh represent the most common anatomic locations for both the sarcomas. (19574885)
References
High Grade Pleomorphic Undifferentiated Sarcomas In Children : A Clinicopathologic Study Of 10 Cases and review of literature. Alaggio R, Collini P, Randall L, Barnette P, Smith L, Coffin CM. Pediatr Dev Pathol. 2010 Jan 7. PMID : 20055602
Overlapping Features Between Dedifferentiated Liposarcoma and Undifferentiated High-Grade Pleomorphic Sarcoma. Chung L, Lau SK, Jiang Z, Loera S, Bedel V, Ji J, Weiss LM, Chu PG. Am J Surg Pathol. 2009 Jul 1. PMID : 19574885