Adalimumab-induced sarcoidosis-like reaction involving oral cavity in rheumatoid arthritis: a case-based review.

Drug-induced sarcoidosis-like reaction (DISR) is a condition almost indistinguishable from sarcoidosis, both clinically and microscopically, consisting of granulomatous tissue reaction associated with a specific therapy. Commonly affected sites are the lungs, hilar lymph nodes, and skin. This report aimed to describe a very uncommon case of DISR with an unique involvement of the oral cavity. A 63-year-old female with a history of rheumatoid arthritis, who was treated with a TNF-α antagonist (adalimumab), presented multiple ulcerative nodules on the hard palate. Laboratory tests and imaging studies failed to show any other alterations. The biopsy specimen demonstrated multiple noncaseating granulomas. Histochemical reactions were negative for acid-fast bacilli and fungi, and immunohistochemical assessment highlighted the presence of normal lymphocytes and histiocytes. With the diagnosis of DISR, adalimumab was discontinued, and complete clinical resolution of the lesions was achieved after 14 months. Although uncommon, DISR should be considered in differential diagnoses of oral granulomatous reactions, especially in cases where the patient is being treated with TNF-α antagonists.