Generalized granuloma annulare associated with lung adenocarcinoma: a case report

We report a case of generalized granuloma annulare (GGA) associated with lung adenocarcinoma. An old woman presented with generalized papules and plaques accompanied by pruritus that persisted for 1 year. Dermatological examination revealed densely distributed annular papules ranging from millet- to mung bean-sized lesions on the head, neck, trunk, and extremities. The majority of papules showed central umbilication, and some lesions coalesced into plaques ranging from pale red to dark red. Histopathological examination revealed epidermal hyperkeratosis with mild acanthosis. The superficial to mid-dermis showed a palisading histiocytic infiltrate between collagen bundles. Alcian blue staining was weakly positive (±), and crystal violet staining was negative. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) of the right lung revealed scattered clusters of atypical cells consistent with adenocarcinoma.