Primary Myxoid Liposarcoma of the Lower Back in an Adult Female Patient: An Extremely Rare Presentation

Myxoid liposarcoma is the second most common type of liposarcoma that typically presents in the lower extremities and has a predilection for men. Manifestation of this tumor in the lower back is rare. We report the first known case of an adult woman presenting with a soft tissue mass in her lower back. Following excision and further workup, the mass was positive for rearrangements of the DDIT3 (CHOP) gene at the 12q13 locus, consistent with the diagnosis of a myxoid liposarcoma. The tumor was noted to be intramuscular and extended into the margins, requiring re-excision at the previous resection site. Biopsy of the re-excised area was negative for evidence of residual myxoid liposarcoma. We report this case to highlight the importance of considering myxoid liposarcoma as a differential diagnosis in soft tissue masses presenting in the lower back.