CLINICAL CASE: A 72-year-old male had a diagnosis of rectal cancer with regional nodal involvement. He started treatment with pelvic radiotherapy and concomitant chemotherapy previous to definitive surgery. One month after the treatment finished he went to the oncology clinic with an strong anal pain and rectorragia, and the doctor prescribed him some pain-killers after a diagnosis of proctitis related to the treatment, but without a physical examination. A definitive diagnosis was established in the fourth medical visit, more than five weeks since the first consultation..
If you were the doctor caring for the patient, what other diagnosis would you consider without more clinical information?
FINAL DIAGNOSIS: FOURNIER´S DISEASE
ANALYSIS: TYPE OF ERROR: Wrong diagnosis/ Delayed Diagnosis
COGNITIVE ASPECTS: REPRESENTATION BIAS: The doctor who saw the patient thought that the symptoms were related to toxicity because this is the usual situation with most of the patients in an oncological clinic where proctitis, cystitis, radiodermitis are common problems.
SYSTEM ASPECTS: In a busy clinic there is a shortage of time to practice a complete physical examination to every patient. Also the perineum is a “dark place” in the body and can be easily missed in a regular visit.
COMMENTS: Fournier’s gangrene, an anaerobic necrotizing cellulitis of the infradiaphragmatic soft tissues, is detected frequently in the perineum, and is a serious pathologic entity with an unpredictable course. Bacteria can reach this area from the anogenital area and is a rare complication of pelvic radiotherapy or surgery. Surgery and antibiotics are the cornerstone of the treatment. The infection can spread up to the body following the peritoneal layer.
MEASURES FOR IMPROVEMENT: Try to expand the differential diagnosis always. Diarrhea, an usual symptom present in radiotherapy toxicity, was absent in this case. Also, a complete physical examination of the area of origin of symptoms should be mandatory.