Palmar atypical lipomatous tumour with spindle cell features (well-differentiated spindle cell liposarcoma):: a rare neoplasm arising in an unusual anatomical location

Lipomatous tumours, both benign and malignant, arising on the hands are uncommon. We present a rare atypical lipomatous tumour with spindle cell features (synonym: well-differentiated spindle cell liposarcoma) arising on the left palm of a 54-year-old male patient. The neoplasm presented as a long-standing, exophytic neoplasm measuring 9x9 cm. The well-circumscribed neoplasm was completely excised, and margins were tumour free. Histologically, the neoplasm showed features closely resembling spindle cell lipoma, being composed of mature adipocytic cells associated with bland, neuroid spindle cells staining positively for CD34. However, focally, atypia of adipocytic and stromal cells as well as scattered lipoblasts were noted, and immunohistochemical stainings showed focal overexpression of MDM2 and CDK4. Aypical lipomatous tumour with spindle cell features may arise very rarely in palmar location and has to be distinguished from a number of benign and malignant mesenchymal neoplasms.