Fig. 1

a Hematoxylin and eosin staining. Diffuse lymphocytic infiltration was observed in the tubulointerstitial area under low magnification. Under high magnification, non-necrotizing epithelioid cell granuloma with Langhans giant cells (arrowhead) was observed. b Ziehl-Neelsen staining. No acid-fast bacilli were observed under low magnification. The formation of a non-necrotizing epithelioid cell granuloma with Langhans giant cells (arrowhead) was observed under high magnification. Scale bars, 50 μm