Spontaneous gas gangrene of the lower limb in a patient with rectal cancer: A fatal diagnostic pitfall

Abstract

Spontaneous or nontraumatic gas gangrene is a rare form of gangrenous disease. 1 It is a serious infection that usually occurs in immunocompromised patients. 2 Symptoms are common to several pathologies. The diagnosis may be delayed especially in the absence of a previous trauma. We report a case of spontaneous gas gangrene of the lower limb that was wrongly taken as thrombophlebitis. | CASE PRESENTATION | Case history and examinationA 43-year-old female patient, without comorbidities, was followed for locally advanced adenocarcinoma of the middle rectum, for 3 months. The carcinoma was classified T4N0M0, invaded the vagina, without any distant metastasis. Neoadjuvant radiochemotherapy was initiated, complicated by bone marrow aplasia, which required transfusions. She consulted for pain and functional impotence of the right lower limb, evolving for 3 days, without other associated signs.On examination, the patient was febrile at 38°C. Hemodynamic parameters were stable. Unlike the left lower limb, the right lower limb was swollen, warm, and painful at palpation with a positive Homan's sign. There were no skin necrosis, bullae, or cutaneous crepitus. The femoral pulse was present, whereas, the popliteal and pedal pulses were weak. The abdomen was soft, depressible, and painless. The rectal examination revealed a tumor of 5 cm from the anal margin, which was painful. | Differential diagnosis, investigations, and treatmentInitially, laboratory tests showed a white blood cell count of 7700 elements/mm 3 and a C-reactive protein (CRP) of 6 mg/L. Hemoglobin was of 8.2 g/dl. The chest X-ray was normal and the urinary cytobacteriological examination