When Radiation Proctitis Gets Way Complicated

Abstract

Radiotherapy is an essential treatment modality for prostate cancer. However, radiation proctitis (RP) is a common complication, with 40% developing rectal hemorrhage. Previous successful experiences in treating cystitis has led to the use of formalin as a treatment modality. Although there have been few published reports of formalin use for RP in the literature, most results show that it is safe and effective. Unusual complications such as fistulae, anal stenosis and colitis have been rarely reported. A 61-year-old man with medical history of prostate cancer status-post radiation therapy completed 6 months ago presented with a 2-week history of rectal bleeding and tenesmus. He denied fever, use of antibiotics, weight loss or previous GI bleeding. Digital rectal exam was painful and with evidence of blood clots. Initial labs showed iron deficiency anemia. Patient underwent colonoscopy which showed a large erythematous ulcerated lesion that extended from anal verge up to 10cm and covered 70% of diameter (Figure 1). Histologic exam was consistent with RP and negative for rectal carcinoma. Initially, patient was provided with supportive management with hydration and steroid enemas. However, he developed progression of symptoms with intractable rectal bleeding requiring multiple blood transfusions as well as severe rectal pain. Pelvic MRI showed bilaterally myositis of the obturator internus and pectineus muscles suggestive of radiation induced myositis. Given severity of symptoms, General Surgery proceeded with rectal instillation of 4% formalin which was unsuccessful for which diverting Loop Colostomy was performed. Patient showed improvement of symptoms until a few days later when he developed hematochezia, fever and leukocytosis. Abdominal CT revealed inflammatory colitis suggestive of formalin-induced colitis which resolved with antibiotics and hydration. Follow up colonoscopy was performed for possible re-connecting surgery which showed anal canal stenosis with 99% of lumen occluded (Figure 2). Patient was referred to Colorectal surgeon whom performed multiple dilations with resolution of stenosis. In this case, anal stenosis and colitis were a complication of formalin instillation as therapy for RP. Both complications are very rare and few cases have been published in which a clinical scenario mirroring our patient presentation and outcome are described. Awareness of rarely described complications is essential for early recognition and treatment.Figure: Large erythematous ulcerated lesion.Figure: Anal canal stenosis.