Objective(s): Spindle cell lipoma (SCL) is a rare variant of lipoma that is uncommon in oral cavity which displays as a slow-growing, painless mass. The histopathologic diagnosis is challenging especially in low-fat/fat-free subtypes, and immunohistochemical staining is of great help in differential diagnosis. The current study aimed to report a rare case of low-fat SCL. Case: A 38-year-old male with a relatively large lesion on buccal mucosa was referred. The interventions included excisional biopsy, H&E staining, and immunohistochemical examinations. H&E study showed a peripheral soft tissue tumor. The underlying connective tissue showed collections of fatty tissue intermixed with spindle cell proliferations. In IHC study, Spindle cells were stained strongly and diffusely for CD34, and no S100 staining was detected in neoplastic spindle cells. Toluidine blue staining showed mast cells that were detected throughout the connective tissue. These findings confirmed the diagnosis of low-fat SCL. Conclusion: Oral pathologists should be familiar with the clinicopathologic characteristics of this rare lesion in order to avoid misdiagnosis.
Atarbashi-Moghadam et al. (Fri,) studied this question.