Inflammatory Myofibroblastic Tumor of the Hard Palate and Gingivobuccal Sulcus Mimicking a Malignant Neoplasm: A Case Report

Inflammatory myofibroblastic tumor (IMT) is an uncommon mesenchymal neoplasm of intermediate biological potential with rare occurrence in the oral cavity. Its broad histopathologic spectrum, coupled with variable immunohistochemical expression, renders it a significant diagnostic challenge, particularly in elderly patients with oral risk habits where malignancy is the primary clinical concern. We report a case of anaplastic lymphoma kinase (ALK)-negative IMT of the myxoid pattern arising simultaneously in the right hard palate and gingivobuccal sulcus in a 75-year-old female with a long-standing history of betel quid chewing. The patient was referred from a tertiary cancer center with a strong clinical and radiologic suspicion of malignancy based on rapid growth, ulceration, and contrast-enhanced CT demonstrating an ill-defined heterogeneously enhancing lesion with alveolar ridge erosion. Two successive biopsies were non-diagnostic, revealing only granulation tissue and fibroblastic proliferation. Subsequent deeper sections and an extended immunohistochemical panel demonstrated diffuse positivity for smooth muscle actin in the characteristic myofibroblastic tram-track staining pattern, desmin, and vimentin, with negativity for ALK and CD34. Focal cytokeratin positivity was noted but was not interpreted as evidence of epithelial malignancy in the absence of diffuse epithelial marker expression. Complete surgical excision was performed with clear margins, and the patient remained recurrence-free at five-month follow-up. This case illustrates the compounding diagnostic pitfalls of oral IMT: dual-site involvement, two failed biopsies, ALK negativity in an elderly patient, and focal cytokeratin positivity risking misclassification as spindle cell carcinoma. Awareness of IMT histologic subtypes, meticulous tissue sampling, and systematic immunohistochemical profiling are essential to avoid misdiagnosis and unnecessary aggressive oncologic treatment.