The Mulberry Wound

A 49-year-old man presents to his primary care physician with a slowly enlarging lesion involving his lips and the inside of his mouth that he first noticed four months ago. He was born and raised in the Andean foothills of Mérida state, Venezuela, where he worked as a coffee farmer for more than twenty years, with daily exposure to moist soil and decaying vegetation. He immigrated to California eight months ago.

He reports fatigue, drenching night sweats, and unintentional weight loss of approximately 9 kg over the preceding five months, along with intermittent low-grade fevers. He has no cough, hemoptysis, or dyspnea. He denies HIV risk factors; a fourth-generation HIV antigen-antibody test returns negative. He takes no medications, has no known immunodeficiency, and does not use tobacco or alcohol.

On examination, temperature is 37.8°C and remaining vital signs are normal. The lips and oral mucosa demonstrate a painless, granular, vegetating ulceration with a distinctive mulberry-like surface punctuated by small hemorrhagic dots, shown below. Bilateral submandibular and cervical lymph nodes are palpable and firm. Chest auscultation reveals diminished breath sounds bilaterally at the bases.

Chest radiography shows bilateral interstitial and nodular infiltrates distributed predominantly in the perihilar and lower lung zones, sparing the apices and costophrenic angles. A biopsy of the oral lesion is performed; Grocott methenamine silver staining reveals large yeast forms measuring 15 to 30 μm in diameter, each bearing multiple peripheral buds attached by narrow necks in a pattern resembling a pilot wheel.