A 30-year-old teacher presented to the outpatient department with the complaints of swelling of the right index finger for the past 2 years. This swelling was slowly progressive in size and was associated with dull pain and difficulty in flexing the affected digit. There was no history of trauma or drug abuse. He had no history of TB or other systemic diseases.
On evaluation, the swelling was found to involve the flexor aspect of the index finger extending onto the palm [Figures 1 and 2]. Fine-needle aspiration cytology of the swelling revealed giant cells suggesting the possibility of giant cell tumour (GCT) of the tendon sheath. A plain radiograph [Figure 3] of the finger was done, and the phalanges and the second metacarpal were found to be free from any visible lesions. The patient was not affordable for any further workup, and hence, MRI was not included in the pre-operative planning.
A provisional diagnosis of GCT of flexor tendon sheath and a differential diagnosis of compound palmar ganglion and tendinous xanthoma was kept, and the patient was planned for exploration/excision after taking consent for amputation of the digit.
The exploration was done under brachial block and tourniquet control. Brunner's zig-zag incision was used to expose the tumour over the flexor aspect of the digit and palm. A lobulated swelling was found extending from the distal interphalangeal joint to the proximal palm of the concerned digit. The swelling was covered by a tough, thickened, fascia-like structure. This covering was gingerly opened at several places to reveal a synovial sac full of small, shiny rice-bodies, which spilled out from the sac due to the excessive pressure inside the sac [Figure 4].
All the rice bodies were evacuated, and the sac was excised. We were unable to differentiate the synovial sheath of the flexor tendon as separate from this thickened sac-like structure, and hence concluded that this sac-like structure was indeed the synovial sheath of the tendon.
The rice bodies along with the excised thickened synovial sheath were sent for the histopathological examination. Flexor tendon pulley was reconstructed by palmar fascia. The wound was closed in layers over a suction drain. The limb was dressed with mild compressive bandage and splinted with a plaster of paris dorsal slab.
On histopathological examination, sections from the intra-lesional content showed acellular, proteinaceous material with mild inflammatory infiltrate [Figure 5] and sections from the cyst wall showed fibrocollagenous tissue diffusely infiltrated by confluent granulomas [Figures 6 and 7] comprising of epithelioid cells, lymphocytes, plasma cells and Langhan's type giant cells suggesting TB.
After the histopathology report suggested the possibility of TB, the patient was investigated and found to have elevated erythrocyte sedimentation rate (ESR) of 32 (Normal range in males below 50 years of age is <15) and a positive Mantoux test (>10 mm). Polymerase chain reaction for Mycobacterium tuberculosis (PCR-Tb) was negative. Chest radiography showed minimal pleural effusion on the left side, and pulmonary physician opinion was sought for the same. Sputum examination by Ziehl-Neelsen staining was positive for acid-fast bacilli (reported 1+). The patient was started on empirical anti-tuberculosis therapy (ATT) and showed improvement of pleural effusion and hand swelling. After regular follow-up, at the end of 9 months of ATT, the patient had no clinical or radiological evidence of the disease.