A 48-year-old man presents with a soft tissue tumor in the right side of his chest. The patient has a history of several bone fractures in the past. Surgical excision of the mass is performed.
Correct answer: C – Phosphaturic mesenchymal tumor (PMT)
PMT is an unusual neoplasm that may involve soft tissue or bone. It has ubiquitous distribution and does not have special predilection for either gender. The tumor can be easily confused with more common soft tissue tumors. However, clinically, most of these patients have a background history of osteomalacia and phosphaturia. By immunohistochemical studies, the tumor may show positive staining for ERG, which is a vascular marker that may add to the confusion in the final interpretation. However, in difficult cases where the diagnosis may not be so apparent, the use of other markers including SATB2, SSTR2A, and CD56 may help in the final interpretation. The treatment of choice is complete surgical resection.