Primary Subcutaneous Myxoid Liposarcoma - A Clinicopathologic Review of 3 Cases with Molecular Confirmation and Discussion of the Differential Diagnosis.

[liposarcoma]

Myxoid liposarcoma typically presents as a deep -seated mass in the lower extremity of adults . Presentation as a primary subcutaneous tumor is rare . Here we discuss clinicopathologic characteristics of three such cases and their differential diagnosis to alert dermatopathologists to this unusual clinical presentation of a potentially aggressive entity .Cases of myxoid liposarcoma were retrieved from archives and consultation files . Inclusion required location above the subcutaneous fascia with no evidence of a metastatic origin . Clinicopathologic features were retrospectively reviewed . Fluorescent in situ hybridization for DDIT 3 (CHOP ) gene rearrangement was performed on all cases .The tumors affected young adults (2 M ;1 F , mean 36 yrs , range 32 -40 yrs ). No prior history of myxoid liposarcoma or deep soft tissue mass was identified . The tumors occurred in the foot , thigh , and hand . All demonstrated multilobular architecture with abundant myxoid stroma , prominent branching capillary vascular network , and lipoblastic differentiation . No dermal involvement was seen . Round cell features were identified in one case and represented < 5 % of the tumor . All patients remain disease-free following local excision only at 6 , 8 and 13 months .Myxoid liposarcoma can rarely present as a primary subcutaneous mass and should be considered in the differential diagnosis of cutaneous myxoid tumors in adults .