# Primary hydatid cyst in the axillary region: A case report

## TL;DR

A rare case of a hydatid cyst in the armpit of a 52-year-old woman is reported, emphasizing the need for awareness and accurate diagnosis in endemic areas.

## Contribution

This case report adds to the limited literature on primary axillary hydatid cysts and underscores their diagnostic challenges.

## Key findings

- Axillary hydatid cysts are extremely rare, with less than 20 documented cases in English literature.
- Ultrasound imaging and histopathological analysis were crucial for diagnosing the cyst.
- Prompt diagnosis and treatment, including surgery and albendazole, are essential to prevent complications.

## Abstract

Hydatid disease, caused by the larval stage of Echinococcus granulosus, is a significant zoonotic infection predominantly affecting the liver and lungs. While hydatid cysts are commonly found in internal organs, cases in the axillary region are rare.

We report a unique case of a 52-year-old female patient presenting with a painless left axillary swelling for two years. Physical examination revealed a firm, mobile mass measuring 10 × 5 cm, with no associated lymphadenopathy. Laboratory tests indicated normal results, while ultrasound imaging confirmed a thick-walled cystic lesion. The patient underwent total cystectomy under general anesthesia, and histopathological analysis confirmed the diagnosis of a hydatid cyst.

Hydatid cysts typically originate in the liver or lungs, with axillary primary cysts being rarely documented, with less than 20 prior cases in English literature. The mechanism for larvae migration to the axillary region remains unclear. The patient exhibited a mobile, asymptomatic mass, and imaging studies were crucial for diagnosis, emphasizing that differential diagnoses should include various axillary masses such as lymphadenitis or neoplasms.

This case highlights the need for awareness of axillary hydatid cysts in endemic regions, which may be misdiagnosed due to their rarity. Prompt diagnosis and individualized treatment, including total cystectomy and adjunctive medical therapy with albendazole, are critical to prevent complications and recurrence of hydatid disease.

•Echinococcus granulosus causes hydatid disease, a zoonotic infection.•Hydatid cysts typically form in the liver and lungs, rarely in other organs.•Axillary hydatid cysts are extremely rare, even in endemic regions.•This report highlights the importance of considering hydatid cysts in the differential diagnosis of palpable axillary masses.

Echinococcus granulosus causes hydatid disease, a zoonotic infection.

Hydatid cysts typically form in the liver and lungs, rarely in other organs.

Axillary hydatid cysts are extremely rare, even in endemic regions.

This report highlights the importance of considering hydatid cysts in the differential diagnosis of palpable axillary masses.