Oral spindle cell/sclerosing rhabdomyosarcoma on mandible with anaplastic lymphoma kinase expression mimicking inflammatory myofibroblastic tumor.

Oral spindle cell/sclerosing rhabdomyosarcoma (SCRMS) with anaplastic lymphoma kinase (ALK) expression is extremely rare, and its diagnosis is very challenging in the absence of clinical or pathological indicators. This case presented with gingival swelling and alveolar bone resorption and was suspected clinically to be periodontitis. A biopsy was performed and, due to immunoreactivity with ALK, the patient was misdiagnosed with inflammatory myofibroblastic tumor. However, based on the combined histological and immunohistochemical features, a revised diagnosis of SCRMS with ALK expression was finally concluded. We believe that this report makes a significant contribution to the precise diagnosis of this rare disease for proper treatment.