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

Introduction: 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. Case Report: 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." Conclusion: 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.