Intracytoplasmic lumina in squamous epithelial lesions of the oral cavity.

Intracytoplasmic lumina are considered a diagnostic feature of adenocarcinomas and have not been reported in squamous cell carcinomas. We are documenting intracytoplasmic lumina in a case of primary squamous cell carcinoma of the oral mucosa and in the oral squamous mucosa in two cases of graft versus host disease, confirming that intracytoplasmic lumina are also present in squamous epithelia and their tumors. Likely explanations for the presence of intracytoplasmic lumina in non-neoplastic and malignant squamous cells of the oral cavity include multiple differentiation, phagocytosis and immune attack on desmosomes.