A 5 year old Indian boy was admitted in April 2007 for investigation of proptosis in his left eye. He complained of fever and swelling in the neck for 2 months and protuberance of his left eye for one month. There was no significant family history. The child had not been immunized.
The general physical examination showed the child to be pyrexial and pale. The left preauricular, submental and cervical lymph nodes were enlarged. Systemic examination was unremarkable.
Ocular examination of the left eye revealed proptosis with the eyeball displaced downwards and forwards (Figure. 1). The extraocular movements of left eye showed limitation of adduction, dextro-elevation and dextro-depression. Vision was counting finger close to face. Relative afferent pupillary defect was present in the left eye but the optic disc and macula were normal and periphery was unremarkable. Fundoscopy was within normal limits. The right eye was essentially normal.
Investigations included Hb 9.4 gm%, leucocytes 9800/cmm, erythrocyte sedimentation rate (ESR) 25 mm in first hour. The chest radiograph was normal. Orbital computed tomography (CT) Scan showed an extraconal soft tissue mass along posteromedial side of left orbit with lateral displacement of medial rectus muscle. The mass was extending inferiorly to infratemporal fossa with signs of bony erosion and superiorly up to superior orbital fissure causing widening of fissure (Figure 2, Figure 3). Mantoux test was positive showing induration and erythema of 15 x 15 mm in diameter. HIV was non-reactive.
Fine needle aspiration cytology (FNAC) of the cervical lymph nodes showed inflammatory granulomatous lesion with caseation suggestive of tuberculosis. Medial orbitotomy and incisional biopsy of mass was performed which revealed similar features. Cultures for acid fast bacilli were negative. Clinical diagnosis of tuberculosis was made on the basis of strongly positive Montoux test and the caseating granulomatous lesion seen in histopathology. The patient was started on antitubercular therapy consisting of isoniazid, rifampicin, pyrazinamide and ethambutol for initial 60 days, followed by isoniazid and riampicin for 10 months.
On antitubercular treatment, proptosis regressed and ocular motility of left eye improved. The extra-ocular movements were full in the last follow-up (Figure 4) and visual recovery was observed over a period of six month. The final visual acuity was 20/30.