Rare Clinical Spectrum: Actinomycotic Osteomyelitis in a Post‐Radiation Oral Squamous Cell Carcinoma Patient With Multiple Systemic Comorbidities

ABSTRACT Background Distinguishing actinomycotic osteomyelitis from osteoradionecrosis is challenging in a medically compromised patient with prior radiotherapy and chemotherapy for oral squamous cell carcinoma, where systemic comorbidities and radiation‐induced changes can mask underlying infection. Case Description A 61‐year‐old woman with prior radiotherapy and chemotherapy for oral squamous cell carcinoma, hepatitis B, diabetes, hypertension and coronary artery disease presented with pain in the mandible and exposed bone suggestive of osteoradionecrosis. Surgical exploration revealed necrotic bone. Histopathological examination using H&E and Grocott Methenamine Silver staining confirmed actinomycotic osteomyelitis. Management included flap elevation, sequestrectomy, curettage, open dressing and antimicrobial therapy, resulting in satisfactory healing despite the complex medical background. Practical Implications Accurate differentiation between osteoradionecrosis and infection is critical. Histopathological confirmation and appropriate antimicrobial therapy improve outcomes, emphasizing careful evaluation in medically compromised post‐radiation patients.