Primary pleural liposarcoma combined spindle cell lipoma of the lung.

Liposarcoma is a malignant adipose tissue tumor which mainly originates from the extremities and retroperitoneum. Primary pleural liposarcoma is very rare. Spindle cell lipoma is a rare benign adipose tissue tumor. A 66-year-old male was referred to our hospital for the evaluation of a mass-like opacity visible on chest X-ray. Computed tomography (CT) scan revealed a well-defined soft tissue mass with internal low attenuations and adjacent multiple nodules in the upper lobe of the left lung, and surgical excision was subsequently performed. Histopathological findings revealed adipose tissue with lipoblasts and spindle cells and immunohistochemical staining (IHC) revealed the tumor cells were strongly positive for CDK4 and MDM2. Histopathological examination of the small lung nodules showed spindle cell proliferation and adipose tissue without positivity for MDM2. Here, we report a rare case of primary pleural liposarcoma combined adjacent spindle cell lipoma of the lung.