Myopericytoma of the mouth floor: The diagnostic and therapeutic challenge—A case report and literature review

Myopericytoma is defined as a rare benign myxoid tumour that is usually found in distal extremities. However, it may rarely affect the oral cavity. Few cases of oral myopericytoma were reported in the literature. A 56‐year‐old female patient presented with a mouth floor lesion. A wedge biopsy performed from the lesion revealed an atypical round cell proliferation, which may be plasmablastic lymphoma or plasmacytoma. Post‐contrast neck MRI described a well‐defined lobulated lesion at the right sublingual region measuring 14 × 21 mm. Transoral wide local excision of the ulcer was performed, and reconstruction of the defect was done using an inferiorly‐based nasolabial flap. Microscopic examination of the excised swelling revealed a tumour proliferation formed of bland‐looking spindle cells alternating with fibroblasts and intervening vascular spaces. No detected mitosis or necrosis in the examined material. IHC staining of the tumour cells was positive for Caldesmon and alpha smooth muscle actin, while Ki67 was positive in 3% of cellularity. Desmin, ALK, B‐catenin, ERG, CD31, and CD138 showed a negative reaction. This led to the diagnosis of bland spindle cell proliferation suggestive of oral myopericytoma with free all surgical margins. Myoepricytoma is a rare benign tumour that rarely affects the oral cavity. Surgical excision is the mainstay of treatment. Local flaps constitute a good choice for the reconstruction of the resection defect.