Cauda Equina Syndrome Due to Silent Rectal Carcinoma

Abstract

THE EARLY MANIFESTATIONS of rectal carcinoma are frequently insidious in onset, with symptoms not directly referable to the rectum. Digital, proctoscopic and roentgen studies may fail to disclose the presence of a rectal tumor, unless these procedures are repeated (1). Anemia, weakness, weight loss, and ill-defined, non -localized bowel distress are the most common symptoms of these silent lesions. Even these complaints are not invariably present, as in the case to be described. Rectal carcinoma does not often metastasize to bone. Mayo and Schlicke found skeletal metastasis in only 1.2 per cent of a group of cases of carcinoma of the colon (2). There are no precise figures on the incidence of sacral involvement, but patients with advanced rectal carcinoma occasionally show evidence of direct extension to the sacrum and sacral nerve roots (3). The case to be presented is interesting in that the initial presenting problem was a cauda equina syndrome. The primary rectal carcinoma remained silent and unsuspected for a considerable period of time. In retrospect it seems that digital or proctoscopic examination should have led to a correct diagnosis. Case Report M. R., a 43-year-old white male, was admitted to the hospital in March 1947, on account of pain in the right gluteal region. His father had died of gastric carcinoma. The patient had been in excellent health until four months before admission, at which time he experienced a sudden onset of right lumbar pain. A month later he discovered a lump in the right gluteal region, which rapidly increased in size. Gradually motor power in the right leg was lost and difficulty in urination and defecation developed. The lump was exceedingly tender, and there was a burning sensation in the right perineal region. No history of blood in the stools was elicited. No significant weight loss occurred. The patient appeared to be well developed and only moderately ill, though he complained bitterly of pain in the right buttock. He was unable to stand and could barely maintain himself in a sitting position. He was most comfortable while lying on the left side with the right leg flexed. A bulging mass was present in the right gluteal region near the midline. It measured 12 em. in diameter and was hard, non-pitting, and tender to light palpation. Rectal examination was difficult, due to extreme tenderness. No irregularity of the rectal mucosa was felt, although a large mass could be palpated posteriorly. The remaining positive findings were neurological in character and included atrophy of the right posterior thigh and gluteal region, absence of the right ankle jerk, motor weakness of the right leg, impairment of all types of sensation on the right over the areas of distribution of the 5th lumbar nerve and all the sacral nerves, with similar though less severe impairment on the left. There were also hypesthesia of the skin of the penis and scrotum on the right and mild weakness of the anal sphincter.