Atypical Spindle Cell/Pleomorphic Lipomatous Tumor with Pleomorphic Hyalinizing Angiectatic Tumor-Like Growth Pattern: A Search for Diagnostic Clues.

Atypical spindle cell/pleomorphic lipomatous tumor (ASPLT) is a newly described adipocytic tumor type, recently included as a separate tumor entity in the fifth edition of the World Health Organization (WHO) classification of soft tissue and bone tumors. Here, we describe a case of an ASPLT with a striking pleomorphic hyalinizing angiectatic tumor (PHAT)-like growth pattern and discuss the diagnostical clues, which led to the diagnosis of ASPLT. To our knowledge, a PHAT-like growth pattern has not yet been reported in the setting of ASPLT.