Visual Diagnosis: 8-year-old Male with a Skin Mass and Inguinal Lymphadenopathy

1. Lauren Hittson, MD* 2. Caitlin Pedati, MD, MPH* 3. Wendy Hoffner, MD* 1. *Pediatrics, Holy Cross Hospital, Silver Spring, MD; Hospitalist Division, Children’s National Medical Center, Washington, DC; Pediatrics, George Washington University School of Medicine and Health Sciences, Washington, DC. A previously healthy 8-year-old boy presents to the emergency department with a red, tender lump in his right proximal inner thigh that his mother noticed the day prior. According to the boy, the lump had been there for several months and has been causing pain with activities such as walking and running. He did not report these symptoms to his mother, so she had not sought care previously. The patient denies fevers, weight loss, rash, or trauma to the area, although he also reports a skin lesion on his right foot. Upon further questioning, he reveals an 8-month history of a hyperpigmented mass on the dorsal aspect of his right foot that has been gradually increasing in size. The mass began as a small skin-colored bump and has slowly grown and darkened over time. It has bled intermittently and blistered but has never been painful. The boy had presented to another health-care facility for evaluation of this mass several months ago but could not tolerate a biopsy attempt under local anesthesia. His family subsequently experienced a lapse in insurance coverage, which resulted in a failure to return for a repeat excision attempt. On physical examination today, the clinician finds a large, palpable, tender mass in the right groin measuring 4 cm with surrounding erythema. Also evident is a hyperpigmented, mobile nodule on his right dorsal foot that measures 2 × 2 cm with areas of darker hyperpigmentation and scaling (Figs 1 and 2). The nodule is only tender with deep pressure. An initial complete blood cell count shows a white blood cell count of 10,700/μL (10.7 × 109 …