Title: A rare case of rectal pain.
Author: Krokos I, Department of Internal Medicine, University of New Mexico, Albuquerque, NM.
Case report. A 64 year-old Hispanic male without a significant past medical history presented with a complaint of “rectal pain.” The pain was worse with bowel movements and as a result the patient reported a fear of eating. The patient denied any associated nausea, vomiting, fevers, chills, melena or bright red blood per rectum. He did report a two week history of a dry nonproductive cough. Additionally he had a 50 pack-year smoking history and multiple sexual partners without consistent use of protection.
On examination the patient was hypotensive with a blood pressure of 80/60 mmHg, tachycardic and had a decrease in weight from 60kg to 45kg in less than 6 months. Breath sounds were clear bilaterally and rectal examination revealed a 4 cm by 4 cm rectal ulceration. Stool exam was brown and guiac positive. Laboratory examination revealed a mild leukocytosis with normal differential and chest radiology showed diffuse patchy opacifications.
Given the patient’s social history, weight loss and chest radiology findings there was concern for human immunodeficiency virus (HIV) infection and Pneumocystis jiroveci pneumonia. He was started on trimethoprim-sulfamethoxazole and admitted for further evaluation. The patient’s hypotension responded to fluids. He was evaluated by gastroenterology and infectious disease services. HIV testing was negative. A new working diagnosis of rectal malignancy with lymphangitic spread to the lungs was made. The patient underwent colonoscopy with biopsies. Sigmoid ulcerations were also noted. Rectal biopsies revealed caseating granulomas and 2+ acid fast bacilli (AFB). Induced sputum later showed 4+ AFB. The patient was placed in isolation and started on a four drug regimen for treatment of miliary tuberculosis (TB).
Discussion. National TB surveillance data reveals that almost one-fifth of TB cases in the United States are extrapulmonary. Gastrointestinal TB is a diagnostic challenge in the absence of a pulmonary infection. Only 2% of gastrointestinal TB cases present after 60 years of age. Most commonly the intestinal lesions are ulcerative. Symptoms include abdominal pain, diarrhea, weight loss, fever, melena and rectal bleeding. Rectal lesions usually present as anal fissures, fistulas or perirectal abscesses. It is essential to distinguish TB enteritis from inflammatory bowel disease such as Crohn’s disease as the initiation of immunosuppressive therapy in a patient with tuberculosis can lead to dissemination. Our patient presented with rectal involvement and likely had disseminated TB. Classic miliary TB is defined as millet like seeding of TB bacilli in the lung and is seen in 1-3% of all TB cases. It can mimic many diseases and in some cases up to 50% are diagnosed ante mortem. A high index of clinical suspicion is important as early diagnosis and treatment correlate with improved outcomes.
Conclusions. Rectal tuberculosis is rare. A case of undiagnosed rectal TB presenting as an acute perianal abscess is reported.