Recurrent Soft Tissue Infection 70 Years After Initial Trauma

Abstract

77-year-old white man came to the clinic with a lump below the left knee. He was punctured in the left leg by a stick of wood after he fell out of a tree 70 years ago. During the next few weeks, a nodule developed at the injury site and existed for several months before it eventually resolved. Three years ago, a new nodule occurred inches above the injury site and grew progressively larger with no recent trauma to the area. He denied any other skin lesions or systemic symptoms such as fever, chills, sweats, weight loss, cough, hemoptysis, or chest pain. His medical history was pertinent for emphysema, squamous cell carcinoma removal of the skin of the left arm, hypertension, hypercholesterolemia, and myocardial infarction. He had a coronary artery bypass graft 5 years prior and abdominal aortic graft stent 1 year ago. The patient was in the military and traveled all over the world. He was born and raised in Florida. On examination, the patient had a temperature of 98.5-F, heart rate of 75 beats per minute, blood pressure of 130/73 mm Hg, and respiratory rate of 20 breaths per minute. The physical examination revealed a nodule near the injury site and no drainage or erythema. Other findings were unremarkable. The patient had a computed tomographic (CT) scan of the chest 5 years ago, and it showed some right lower lobe atelectasis and a calcified granuloma within the right lower lung. Laboratory results were unremarkable. A magnetic resonance imaging of the leg showed a nodule superficial to the tibial area with no involvement of the muscle or bone (Fig. 1). The nodule was surgically resected. The histopathological findings showed numerous necrotizing granulomas within the dermis. The Gomori methenamine silver stain revealed many septated hyphae with 45-degree bifurcation. The culture of the tissue specimen grew a black dematiaceous mold. The fungal isolate failed to sporulate despite completion of the following 4 microbiological manipulations: subculturing the original isolate twice; overnight exposure of plates to ultraviolet light or refrigeration; inoculation of new media with remnants from the original sample; and submission to a reference laboratory. Molecular fungal identification was not available as a service at our reference laboratory. Preliminary identification of the isolate was a nonsporulating black mold. Slide culture setups in our laboratory to induce conidial formation use potato flake, cornmeal, and potato dextrose agars. What is your diagnosis? Diagnosis: phaeohyphomycosis. The dematiaceous molds are a group of ubiquitous, darkly