Primary hydatid of posterior thigh and popliteal fossa: A rare case report

Abstract

Hydatid disease of skeletal muscle is a rare entity. Liver followed by lung are the most common sites of hydatid cyst. Incidence of unusual sites which include spleen, kidney, mesentry, ovary, brain, skeletal system is 7,8 %. Skeletal muscle has the lowest incidence of primary hydatid among the unusual sites. Here we report a young female with rare primary hydatid disease of left posterior thigh extending into popliteal fossa.

Keywords: Cyst; Echinococus granulosus; Hydatid and rim sign; Popliteal; Skeletal muscle.

Figure 1

CEMRI showing T1 hypo-intense and T2 hyperintense lesions with multiple internal daughter cyst within the intramuscular plane of posterior thigh causing compression effect on semi-membranosus and biceps femoris with anterior displacement of popliteal vessels and associated nerves.

Figure 2

Large cyst along with pericyst overlying the popliteal vessels between biceps femoris and semi-membranosus. Common peroneal nerve was identified and gently retracted away.

Figure 3

Cyst along with pericyst carefully separated from the perimysium protecting the underlying vessels and nerves. 15 × 12 cm cyst after excision.

Figure 4

Histopathological section showing acellular eosinophilic laminated membranes along with pericyst comprising of fibrocollagenous tissue infiltrated by dense chronic inflammatory infiltrate rich in lymphocytes and plasma cells.