Acta Dermato-Venerelogica Issue No 7, 2017 97-7CompleteContent | Page 28

QUIZ SECTION Ulcerative Plaques and Nodules on the Lower Extremity: A Quiz Amit MITTAL, Antonio SUBTIL and Jonathan S. LEVENTHAL* Department of Dermatology, Yale University School of Medicine, 15 York Street, LMP 5040, New Haven, CT 06510, USA. E-mail: jonathan. [email protected] A 65-year-old man presented to clinic with painful lesions on his left lower extremity for the past 2 months. His medi- cal history included Crohn’s disease treated with prednisone 30 mg daily and ongoing treatment of cholangiocarcinoma with gemcitabine and oxaliplatin. The patient initially noted an ulcerative lesion on the left lower calf and then developed draining abscesses proximally on the thigh over a course of 8 weeks. He reported traumatic injury of the calf, which he believed was secondary to an arthropod bite while out- doors. The patient denied fevers, chills, and other systemic symptoms except for chronic diarrhea from Crohn’s disease. Physical examination of the left calf revealed an er- ythematous ulcerative plaque with fibrinous base and hemorrhagic crust (Fig. 1, inset). Distributed on the thigh and proximal calf were tender, suppurative, erythematous subcutaneous nodules and ulcerative plaques in a lym­ phangitic pattern (Fig. 1). No other lesions were noted on skin examination. On histopathology, punch biopsy demonstrated necrosis and a dense inflammatory infiltrate in the reticular dermis and panniculus composed primarily of neutrophils (Fig. 2A). Gram stain identified elongated, bacillary, beaded and filamentous Gram-positive bacterial organisms within the suppurative infiltrate (Fig. 2B). Both GMS and PAS stains were negative for fungi, and AFB stain was negative for mycobacterial organisms. What is your diagnosis? See next page for answer. 866 Fig. 1. The patient gradually developed suppurative, erythematous nodules proximally on the calf and thigh over the course of 2 months. (inset) An ulcerative plaque with fibrinous base and hemorrhagic crust was noted on the left lower calf. doi: 10.2340/00015555-2659 Acta Derm Venereol 2017; 97: 866–867 Fig. 2. (A) Punch biopsy revealed necrosis and a dense inflammatory infiltrate composed predominantly of neutrophils in the mid to deep reticular dermis and panniculus (hematoxylin and eosin stain, original magnification x 100). (B) Gram-positive beaded and thin filamentous bacterial rods were identified within the inflammatory infiltrate (tissue Gram stain, original magnification x 600). This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2017 Acta Dermato-Venereologica.