A thirty-two-year-old adult male presents with a chronic suppurative lesion on the angle of the jaw. Microscopic examination shows small abscesses immediately beneath the epidermis with moderate growth of epithelial cords. In the abscess, there are oval, unicellular organisms measuring 20 µm in diameter and having a thick, double-refractive cell wall and cytoplasm containing refractive granules and vacuoles. Which of the following is the most likely diagnosis?