[Histological study of intractable recurrent ulcer of the oral cavity and pharynx].

Intractable recurrent ulcer of the oral cavity and pharynx was defined as irregular ulcerative lesions occurring only in the oral cavity and pharynx, showing no specific findings on clinicohematological examinations, which recurred easily and were resistant to various treatments for at least one month. Twenty-two cases with intractable recurrent ulcer were studied histologically. The following results were obtained: 1. Five histological types (LP type, LPE type, NL type, NLE type and NLP type) were identified, according to the invasive cells present, using H.E staining. 2. Subclasses of the invasive lymphocytes were classified using UCHL1 and L26. As a result, both LP type cases showed dominant T lymphocyte invasion. 3. Appearances of the activated T lymphocytes and Langerhans cells were studied using anti-Human HLA-DR and epithelial and endothelial expression of HLA-DR were observed. As a result, the characteristic findings of each histological type were demonstrated. These results suggest that cellular immunity may participate in the occurrence and progression of intractable recurrent ulcer. However, its role in the causes and effects of ulcer cannot be confirmed at this point.