An invasive and diffuse cranial actinomycosis with a dura-based mass mimicking a brain tumor: illustrative case

Invasive and diffuse cranial actinomycosis with a dura-based actinomycetoma is a rare presentation that poses a diagnostic challenge due to its nonspecific manifestations. Imaging is helpful in localizing and characterizing the lesion; however, histopathology remains the gold standard for diagnosing actinomycosis. A high index of suspicion is also warranted in patients with predisposing factors to promote an early diagnosis and the initiation of appropriate treatments to improve functional recovery and limit residual deficits. https://thejns.org/doi/10.3171/CASE24210.