Hydatid cyst in soft tissues of the calf

ABSTRACT

A rare case of primary intramuscular hydatid cyst is reported here because of its unusual presentation. A young man presented clinically as having a soft tissue nodular mass in right calf. Histopathological examination revealed characteristic findings, which were consistent with hydatid cyst. A high level of awareness concerning the occurrence of these cysts is important, especially in regions where echinococcus is endemic. Radiological investigations can be helpful in non-invasive diagnosis of the condition. Surgical treatment follows the principles of malignant tumors, namely, wide surgical resection. A 40 years old man of rural origin had six months history of painless lump in right calf region, which gradually started increasing in size. There was no history of trauma, fever or weight loss. Local examination revealed a walnut sized, ovoid, non-tender mass in the posteromedial aspect of right calf in its middle third. The mass was found to be attached to the deep muscles. The clinical picture was suggestive of soft tissue tumor. General physical examination revealed no abnormality. Systemic examination was also normal. No evidence of visceromegaly was noted. Chest was clear. Plain radiograph of the right leg revealed an ovoid, partly calcified 4x3 cm mass in soft tissues on posteromedial aspect of mid-calf, with intact bones. Total leukocyte count [TLC] was 6,700 micro L with eosinophils upto 8%. Ultrasonography of the lesion, using 7.5 MHz transducer, was performed, which showed a well-defined 4x3 cm septated, cystic mass with multiple daughter cysts. Fluid level was also noted in one of the cysts. The findings were suggestive of hydatid cyst. Chest radiograph and abdominal ultrasonography were performed, which were normal. The patient underwent surgery. On exploration, a hydatid cyst attached to fascia covering tibialis posterior was found. This was excised and soft tissue washed with 0.5% silver nitrate solution. Histopathology confirmed echinococcus cyst. The patient was put on medical treatment and discharged in a satisfactory condition