Fig. 21.

Actinomycosis in two different patients: a 24-year-old female with a history of chronic granulomatous disease presented with fever and left upper quadrant pain. Her spleen was palpable on physical examination. Gray-scale US exam demonstrated a cystic lesion with septations in the upper pole of the spleen (arrows), which was confirmed to be consistent with an abscess due to Actinomyces israelii. b 30-year-old female patient with acute myeloid leukemia presented with intermittent low-grade fever and abdominal discomfort. Axial plane postcontrast abdominal CT showed hypodense branching lesions (arrow). US-guided aspiration and culture grew gram-positive filamentous branching bacilli consistent with Actinomyces spp