Development of Fournier gangrene after chemotherapy despite the absence of anorectal lesions originally: A case report

Abstract Background Fournier’s gangrene is a life-threatening disease because the infected region expands very quickly, the patient easily suffers septic shock, and the mortality rate is high. Usually, Fournier’s gangrene will occur when there is a wound or tumor, from which a specific bacteria intrudes into soft tissue. We encountered a patient with Fournier’s gangrene due to severe myelosuppression after chemotherapy, although there was no initial lesion on the anus and rectum. Case presentation: A 54-year-old man with a recurrence of left testicular cancer had been administered chemotherapy. Twelve days later, the patient complained of severe pain around the anus. The following day, the patient went into septic shock. Upon visual inspection, there was dark purple skin discoloration on the left side of the anus. Laboratory data revealed severe neutropenia. Computed tomography revealed a high density of soft tissue on the left side of the anus and gas bubbles in the left femoral ring. We diagnosed the patient with Fournier’s gangrene due to a severe immune suppressive state after chemotherapy. We emergently removed necrotic tissue as much as possible. However, because the patient was in severe sepsis status, he needed careful management in the intensive care unit for 32 days. After the first emergency operation, we performed additive removals several times. Finally, 391 days after the initial surgery, the patient was discharged from our hospital. The tumor has not recurred, and the patient is under outpatient observation in the urology department. Conclusion Despite having no anorectal lesions initially, if patients who receive chemotherapy and are in a severe myelosuppressive state complain of severe pain in the perianal area and have a dark purple discoloration of the skin around the anus, the possibility of Fournier's gangrene should be considered.