Radiological evolution and delayed resolution of an optic nerve tuberculoma: Challenges in diagnosis and treatment

Optic nerve tuberculomas are rarely reported and their natural history, prognosis, and duration of required treatment remain unclear. A 40-year-old immunocompetent male presented with complete loss of vision in his right eye, which had evolved over 6 weeks. He had optic atrophy on examination. Initial imaging showed right optic nerve swelling and thickening suggesting an infiltrative inflammatory optic neuropathy (infectious or noninfectious). Serial imaging revealed appearance of ring enhancement with a necrotic centre. Biopsy and culture of the coexistent parietal lobe lesion revealed Mycobacterium tuberculosis. Persistent optic nerve granuloma with evidence of radiological improvement was noted at 18 months follow-up with antituberculous therapy (ATT). Visual recovery could not be achieved. The salient features in this case include the clinical presentation initially mimicking an infiltrative or compressive optic neuropathy, rapidradiological evolution into a tuberculoma, subtle paradoxical radiological worsening after initiation of ATT and persistence of granuloma on follow up scan. The challenges involved in early diagnosis and during the treatment course will be discussed.