Anaplastic large cell lymphoma with primary involvement of the skeletal muscle: A case report.

The present study reported the case of a patient with primary anaplastic large cell lymphoma (ALCL) occurring in the left major psoas. A 24-year-old male patient presented with one-month history of left lower back pain, which had been exacerbated for 10 days prior to admission. Magnetic resonance imaging (MRI) scans revealed an enlarged major psoas muscle that protruded into the inguinal region. The presence of an intense soft tissue mass on MRI scans, as well as the results of fine-needle aspiration biopsy and immunohistochemical analysis of the mass, may help establish an early diagnosis, allowing for the appropriate treatment strategy to be initiated.