[Malignant psoas syndrome secondary to uterine cervical carcinoma]

A 40-year-old woman was scheduled to receive chemotherapy for a high-risk common B-cell acute lymphoblastic leukemia (ALL), diagnosed 10 months earlier in the wake of lower limb bruising and petechiae, and metrorrhagia. At that time, she had thrombocytopenia and a normal transvaginal gynecological ultrasound. Upon admission, she complained of a 3-month history of incapacitating left groin pain radiated to the thigh, and right lower quadrant abdominal pain associated with diarrhea. On physical examination, she had tenderness in the right iliac fossa and a positive psoas sign on the left. Computerized scan of the abdomen and pelvis reported an image compatible with a left psoas abscess and signs of typhlitis. The biopsy of the left psoas muscle demonstrated infiltration by nests and cords of moderately differentiated keratinizing squamous carcinoma. Gynecological examination revealed macroscopic abnormalities of the cervix correlated with the same histopathological diagnosis. The second primary cancers most frequently associated with ALL are Hodgkin lymphoma, squamous skin cancer, endocrine tumors, kidney cancer, non-Hodgkin lymphoma, and breast cancer. Muscle metastases from solid tumors are rare, and usually arise from the lung, kidney, thyroid, and melanoma. Malignant psoas syndrome is caused by neoplastic infiltration of the muscle. The differential diagnosis should be made with a psoas abscess, which may arise from typhlitis if secondary. We have not been able to find records of cervical cancer as second primary cancer after ALL.