Rare case of Hydatid cyst in soft tissue reported

Dr.Biniam at Djibouti medical centre has reported a rare case of Hydatid cyst in soft tissue. The case has been published in the Journal of medical case reports. 

Hydatid disease is due to infection by the tapeworm Echinococcus granulosus in its larval or cyst stage. Of all cases of hydatid cyst, 70% of them are formed in the liver. A few of the ova pass through the liver and are caught in the pulmonary capillary bed; ova that escape the pulmonary capillary bed enter systemic circulation, forming cysts in the lung, spleen, brain, or bones. Some cysts spontaneously collapse and may disappear or calcify, while other cysts steadily increase in size, displace or compress healthy tissue and organs, and may become complicated. The annual growth rate of the cyst is usually approximately 1–3 cm in diameter.

It is very rare for a hydatid cyst to be located in soft tissues which are seen only in 0.5–4.7% of patients.

A 22-year-old Somali had presented to the surgical referral clinic in March 2019 with the main complaint of progressive swelling associated with pain over the left plantar side of his foot. The patient had noticed the swelling 1 year prior to the presentation. There was no history of trauma to the site, no difficulties of walking, no discharge from the swelling, and no lesions noticed on other sites also the patient had no abdominal pain or discomfort, no chest pain or cough.

With the initial impression of callus; the patient was prepared for a minor surgical operation to remove the mass after having completed a full pre-op investigation.

A transverse incision was made over the lump, followed by dissection of the subcutaneous tissue. Upon exposing the subcutaneous tissue, a typical endocyst membrane covering the hydatid cyst was encountered. Further dissection revealed the pericyst and endocyst very clearly. Protecting the surrounding area with iodine-soaked gauze, the endocytic membrane was aspirated, revealing a sandy content.

It was then injected with hydrogen peroxide and re-aspirated. Later, the whole intact membrane was dissected out; a pericystic cavity lavage was done using hydrogen peroxide too. The subcutaneous tissue layers and the skin were closed in the standard manner. The specimen was sent for pathology which reported a germinative layer that consisted of daughter cysts and brood capsules with scolices and clear fluid content.

"Although the hydatid cyst is rare, a high index of suspicion and identification of the typical endomembrane of the cyst could guide intraoperative diagnosis. Chemotherapy with albendazole for a short duration of 15 days could suffice for a subcutaneously located hydatid cyst if the cyst is removed intact with no local spillage" states Dr.Biniam Ewnte.

The report concludes that no local or systemic recurrence been identified in the patient so far.

For further reading click on the link below,

https://doi.org/10.1186/s13256-019-2337-8