Pseudotumor - Cysticercosis of the Flexor Digitorum Profundus Mimicking Volkmanns Contracture

Cysticercosis leads to a cyst formation known to occur due to the Taenia solium parasite. Patients normally present with seeding and formation of the cysts in the central nervous system (CNS) as neurocysticercosis (NCC). Intramuscular cysts are rare presentations and are mostly incidental findings in NCC patients. We present a rare case of a rapidly progressing isolated cysticercosis of the flexor digitorum profundus (FDP) muscle leading to a pseudotumor and presenting with pseudo-Volkmanns contracture and a positive Volkmanns sign.

A 26-year-old right-hand dominant vegetarian female presented with a 3-month-old progressive swelling on her right forearm with no antecedent trauma history. A positive Volkmann's sign was present. Radiographs were normal, and ultrasonography showed a cysticercus cyst in the FDP muscle belly with a multiseptated abscess around the tendons of the middle, ring, and little fingers at the musculotendinous junction. Bones and nerves were spared. After ruling out CNS involvement and providing oral antiparasitic cover, she underwent a successful surgical exploration with cyst excision, debridement, and freeing of the involved tendons. Immediately post-operatively, she was able to completely extend the three involved fingers without flexion at the wrist joint (resolving Volkmann's sign). She reported significant improvements in the functions of daily life. She was protected with a splint for 2 weeks. There was no recurrence, and the swelling subsided. Histo-pathology reports depicted cysts with visible scolices.

It is important to consider the possibility of 'Myoparasitism' in atraumatic cases showing contractures. Clinching the right diagnosis is essential and best done with a multidisciplinary approach with ultrasonography, magnetic resonance imaging, electromyography, and nerve conduction velocity studies. It is essential to rule out life-threatening NCC beforehand and offer prophylaxis. Surgical exploration is generally indicated to regain normal function and free the involved structures.