Review Question - QID 212442

A 42-year-old woman presents to clinic complaining of multiple symptoms including skin lesions and worsening bone pain. She just returned from a 6-month stay in Guatemala, where she volunteered to build homes in an underdeveloped community. While she was there, she developed scaling papulonodular skin lesions on her left hand and right wrist. She also complains of bone pain, specifically in her right forearm and right thigh, and a persistent dry cough. She states she has been very tired lately, which is why it took her so long to see a doctor when she returned from her trip. Since returning, she has been living in Arizona for the past 2 weeks with her brother who owns 2 parrots and a dog. The patient’s temperature is 99°F (37.2°C), blood pressure is 110/68 mmHg, pulse is 88/min, and respirations are 17/min with an oxygen saturation of 97% on room air. Her complete blood count reveals pancytopenia. A peripheral blood smear shows evidence of lymphoblasts. A computed tomography of the chest reveals multiple, centrilobular nodules in the left upper lobe. A radiograph of the right thigh and right upper extremity shows osteolytic bone lesions. A biopsy of the skin lesion on her left hand is obtained, and the results are shown in Figure A. Which of the following is the most likely diagnosis?