Granules in Granular Cell Lesions of the Head and Neck: A Review

Abstract

Granular cell lesions of the oral mucosa, jaws, and salivary glands constitute a heterogeneous group of lesions which may be either odontogenic, salivary gland, or metastatic in origin. Granular cells in these proliferations most commonly are the result of lysosomal accumulation, aging, degenerative, metabolic alteration, increased apoptosis, cytoplasmic autophagocytosis, and many more. Many benign and malignant tumors that occur in the oral cavity contain granular cells as a characteristic component of their pathology. Sometimes dilemma exists in the proper diagnosis of these granular cell lesions and the cell of origin because they share similar light and electron microscopic features. Therefore, immunohistochemistry helps to confirm histologic impressions and differentiate other neoplastic entities with granular cytoplasmic features. Granularity in a normal histopathology is a rare but innocuous change and does not influence the biologic behaviour of smooth muscle tumors except few lesions such as cutaneous granular cell angiosarcoma and granular cell ameloblastoma which have shown poor prognosis. This paper aims to review the clinical and pathologic features, different immunohistochemical profiles of granules in granular cell lesions of head and neck with an attempted working classification.