A Rare Case Report of Primary Hydatid Disease of the Scapula - an Unforeseen Diagnosis!

Hydatid disease of the bone is a parasitic infestation in the form of cystic echinococcosis by a tapeworm echinococcus granulosus. Its manifestation in the bone is relatively low and has the ability to mimic other skeletal pathologies.

We came across a 30-year-old male farmer with complaints of sero-purulent discharge from a sinus tract wound in the axilla for the past 3 years. He had been previously evaluated elsewhere with blood investigations, pus culture/sensitivity tests, MRI, and CT scans. Blood reports and culture/sensitivity tests were inconclusive and imaging tests were suggestive of a sinus tract originating from the right scapula. He was incorrectly diagnosed as a case of Tuberculosis of the Scapula and started on anti-tubercular medications for 9 months which was ineffective. To confirm the diagnosis, a biopsy was taken from the scapular lesion through a posterior approach. Histological tests revealed a cystic lesion composed of trilaminar membrane consisting of dead and degenerating scolices consistent with "Hydatid Cyst of Bone."

Hydatid disease of the bone has an inconsistent clinical picture which makes diagnosing this rare disease even more difficult. A high suspicion for hydatid infestation in bone pathologies could help in diagnosing the disease at the earliest.