Submucosal spreading bowel cancer

Abstract

Dear Sir, Classical teaching states that direct circumferential or radial spread of rectal cancer is more common than longitudinal spread with distal microscopic spread being categorised as rare. If it is present, it usually extends for less than 1 cm or if more extensive, implies the presence of an advanced tumour with a poor outcome form distant metastasis before local recurrence. We present a rectal tumour with a discontinuous deposit of tumour 4 cm distal to the primary with mucosal sparing on both the primary lesion and the deposit and discuss the impact of this rare presentation on the surgical management of the patient. A 55-year-old gentleman presented to the colorectal services with a history of rectal bleeding, both dark and bright red, and a recent change in bowel habit with tenesmus. Surgical history included a right inguinal hernia repair 20 years previously but no previous colorectal problems. Abdominal examination was unremarkable but per rectal examination demonstrated a palpable, mobile ulcerating tumour at about 7 cm, located mainly posteriorly and roughly 4 cm in size. The tumour was biopsied and the initial histology confirmed infiltrating adenocarcinoma. Staging magnetic resonace imaging showed a T3 annular tumour of the lower rectum. The distal aspect of the tumour was approximately 2 cm above the anorectal junction and the intervening rectal mucosa was unremarkable. The circumferential resection margin (CRM) of the tumour was not threatened. Computed tomography of the abdomen and pelvis, and a chest radiograph showed no evidence of metastatic disease. On the basis of the clinical and radiological findings, the patient was considered for an anterior resection. In line with the unit policy before resection, the patient underwent an examination under anaesthetic. At this time, a suspicious nodule was found distal to the tumour, just above the anorectal ring. There was a gap of more than 2 cm clinically between the lower edge of the rectal tumour and the lower anorectal nodule. The nodule was biopsied and histological examination of the lower anorectal biopsy specimen revealed a largely preserved surface epithelium and glands. However, malignant glands were found in the submucosa, surrounded by a mixed inflammatory infiltrate and fibroblastic reaction in keeping with the features of infiltrating adenocarcinoma in submucosal location. In view of the secondary lesion, the decision was taken after discussion at the multi-disciplinary meeting and following discussion with the patient to proceed to an abdomino-perineal excision of rectum. Histological examination of the resection specimen revealed the rectal tumour to be a moderately differentiated Int J Colorectal Dis (2008) 32:211–212 DOI 10.1007/s00384-007-0352-5