Disseminated tuberculosis presenting as irido-ciliary granuloma in an immunocompetent patient

Case report A 17-year-old boy presented with reduced vision in the right eye for 2 months. Best corrected visual acuity (BCVA) was counting fingers 2 m and 6/6 in the right and left eyes, respectively. Intra-ocular pressures were in the right 18 mmHg and left 16 mmHg. Slit lamp examination of the right eye showed mutton fat keratic precipitates and multiple densely vascularized granulomatous lesions on the anterior surface of iris that seemed to arise from angle of anterior chamber (Fig. 1a). A vascularized scleral nodule, with surrounding ciliary congestion, was noted near the inferior limbus. The right fundus was not visible. The left eye showed optic disc edema, but no other inflammatory signs. B scan ultrasonography of the right eye showed disc edema, but not choroidal thickening or vitreous echoes. Ultrasound biomicroscopy of the right eye showed the iris lesion extending into ciliary body and then onto sclera (Fig. 1b). Systemic examination revealed left submandibular lymphadenopathy (non-tender, matted, rubbery consistency; Fig. 1c). Based on the above findings, we diagnosed irido-ciliary granuloma with scleral extension in the right eye, associated with cervical lymphadenopathy of likely tubercular aetiology, and probable raised intracranial pressure. However, the tuberculin test was negative (4 mm induration with 5TU) and chest radiogram was normal. Fine needle aspiration cytology of the submandibular lymph node showed mixed population of reactive lymphoid cells with scattered histiocytes and plasma cells. There was no evidence of epithelioid granulomas or caseous necrotic material. Ziehl–Neelsen stain was negative for AFB. We therefore biopsied the scleral nodule that revealed wellformed granulomas composed of epithelioid histiocytes, chronic lymphomononuclear cells and plasma cells and on 20 % acidfast staining showed scattered AFB in the tissue (Fig. 1d). PCR showed positive for MTB with three different gene targets (IS6110, MPB64 and protein B). Subsequently, computed tomography (CT) of head showed multiple ring enhancing lesions in the brain parenchyma (Fig. 1e). CT thorax showed a small non-cavitatory lesion in the left lung (apical lobe, Fig. 1f). Sputum tested positive for AFB. ELISA for HIV was negative. Based on neurologist’s recommendation, we initially treated the patient with intravenous dexamethasone (to reduce risk of paradoxical worsening of brain lesions) for 3 days, followed by fivedrug ATT (anti-tubercular therapy—isoniazid, rifampicin, ethambutol, pyrazinamide and streptomycin) and oral corticosteroids (1 mg/kg/day, tapered). Irido-ciliary granuloma, optic disc edema and cervical lymphadenopathy gradually resolved over the next 2 months (Fig. 1g). BCVA of the right eye improved to 20/60. Thereafter, ATTwas changed to isoniazid and rifampicin for another 7 months—right BCVAwas 20/50, and iris lesions had completely resolved with minimal residual fibrosis.