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Journal of Cancer Research and Therapeutics, Vol. 5, No. 4, October-December, 2009, pp. 328-330 Case Report Primary squamous cell carcinoma of the cecum Mondal SantoshKumar Department of Pathology, Medical College, Kolkata Code Number: cr09080 PMID: 20160376 DOI: 10.4103/0973-1482.59900 Abstract Primary squamous cell carcinoma (SSC) of cecum is a very rare malignant neoplasm. The first case was reported by Schmidtman in 1919. Here, a well-differentiated, keratinizing SSC of cecum in a 34-year-old male patient is being reported. The neoplasm originated from surface epithelium, and invaded the bowel wall up to subserosal fat space. No predisposing factor was detected. Clinical features were that of an adenocarcinoma of the colon. Postoperative chemotherapy was given for 6 months to eradicate any micrometastasis. The patient is free of disease 2 years after having had the tumor removed. The case is being presented because of its rare occurrence.Keywords: Cecum, primary squamous cell carcinoma Introduction Proximal to the anal canal, primary squamous cell carcinoma (SCC) is an exceedingly rare entity. SSC and adenoacanthoma occur in the colon and upper rectum 0.05% as frequently as adenocarcinoma. [1] Any malignancy 7 cm proximal to the dentate line should be excluded as primary SSC. [2] Predominantly, SSCs are found to be right sided in comparison to adenocarcinoma. [3] Before regarding such a case as primary carcinoma, exclusion of possibilities of metastatic deposit in the cecum from a source elsewhere or direct extension from other sites is necessary. Some predisposing conditions are thought to play a role in the development of primary SSC. Inflammatory bowel disease (specially ulcerative colitis), schistosomiasis, pelvic irradiation, villous adenoma, and duplication of intestine are believed to induce such neoplasm, though in this case there was no such predisposing factor. [2],[3],[4] Case Report A 34-year-old male patient came with a complaint of worsening abdominal pain, constipation, vomiting, and a mass in right lower quadrant of the abdomen. He had loss of appetite, weight loss, and generalized weakness for last 2-3 months. Clinically, the patient was anemic, and a hard ill-defined palpable pelvic mass was found on the right side of the abdomen. A rectal examination did not reveal any abnormality. Clinical diagnosis was subacute intestinal obstruction due to intestinal (illeocecal) tuberculosis. Barium enema showed filling defect in the cecum. Sonography revealed a heterogeneous space-occupying lesion (SOL) in the right iliac fossa with bowel wall thickening. On exploratory laparotomy, a hard mass in the cecum was found. No other lesion was detected in other parts of intestine or adjacent viscera. Pathological Findings During the surgery, right hemicolectomy was done to excise portion of the terminal ileum, ileocecal valve, appendix, cecum with tumor, and colon up to hepatic flexture. A hard tumor measuring 6.2 × 4.7 cm encircling the cecum was detected. The cut section revealed a gray-white, solid tumor originating from the mucosal layer and infiltrating up to subserosa grossly. Depth of tumor invasion from the mucosal layer to the underlying tissue was 4.1 cm. Areas of necrosis were found in the tumor [Figure - 1]. Proximal and distal resection margins were free of tumor. Two large pericolic lymph nodes resected along with the tumor were grossly unremarkable. Microscopically, multiple sections revealed a well-differentiated keratinizing SSC involving mucosa, submucosa, and muscularis propria, and reached up to subserosal fat space [Figure - 2]. However, serosa was uninvolved. Keratin pearl formation and intercellular bridges were evident [Figure - 3]. Periodic Acid Schiff (PAS) stain for mucin was negative. Both lymph nodes were free from metastasic deposit. Discussion The first reported case of squamous cancer of the colon was by Schmidtman in 1919 in a 65-year-old man. [5] Till date, only two cases of SSC of right hemicolon have been reported from the Indian subcontinent, and only one of them arose from the cecum. [2],[6] Primary SSC is diagnosed when following criteria are met. (1) No other lesion of SSC exists elsewhere that could be a source of metastasis or direct extension. (2) No contiguity should exist between the tumor and anal squamous epithelium. (3) The affected segment of bowel is not in continuity with a squamous lined fistula. (4) Intercellular bridges are visible with or without keratin pearl formation. Mucin should be absent. All the above-mentioned criteria were satisfied in our case. In the literature, several theories have been proposed regarding the possible pathogenesis of primary SSC of the colon: (a) squamous metaplasia of glandular epithelium from chronic irritation (e.g., radiation); (b) malignant transformation of heterotrophic rests of squamous epithelium in the submucosa; (c) aberrant differentiation of multipotential colonic stem cells to squamous cells due to genomic derangement and subsequent malignant change; (d) de novo origin from embryonal nests of ectodermal cells; and (e) mucosal injury causing proliferation of uncommitted reserve or basal cells. Caucasians have a higher risk of proximal colorectal cancer and this risk increases with time. Chinese patients, in contrast, were more likely to have distal colorectal cancer and developed the disease at a significantly early age than White patients. [7] Recently, a trend with the decrease percentage in rectal cancer and the gradual increase in the right hemicolon cancer with an increase in patients′ age has been seen. Xu et al. observed half of the colorectal cancer in the rectum; the rest occurred in the left and right hemicolon. [8] The clinical features of primary squamous cancer are exactly the same as those of adenocarcinoma of the colon. The primary management of stage II and III colon cancer is surgical resection. However, there is a significant risk of residual micrometastasic disease in these patients. Therefore, adjuvant therapy is given to eradicate any microscopic metastatic disease. Adjuvant therapy for high-risk stage III colon carcinoma is considered standard treatment, and patients demonstrate disease-free and overall survival benefits. [9] It is recommended that patients with stage III colon cancer receive postoperative treatment of either 6 months of 5-fluorouracil (5-FU) and leucovorin (folinic acid) or 12 months of 5-FU and levamisole. The role of adjuvant chemotherapy in patients with stage II colon cancer is controversial. Adjuvant therapy for anything other than stage III colon cancer should be given only as part of a formalized trial. The College of American Pathologists (CAP) consensus statement suggested that a minimum of 12-15 lymph nodes should be examined to determine node negativity. In the present case, serosa was uninvolved. Only enlarged (≥5 mm) nodes were sampled (2 in number) due to the increased burden of biopsied tissues and limited resources in the pathology department. However, the patient was given 6-month chemotherapy (5-FU and leucovorin) to eradicate any possible micrometastasis. Williams et al. reviewed 21 cases of squamous carcinoma of the colorectum and found that 38% had regional lymph node metastases and 27% had liver enlargement at the time of diagnosis. [10] In this case, two large regional lymph nodes were uninvolved and showed reactive hyperplasia. The overall 5-year survival rate for those patients was 30%, which is less than 50% for those with adenocarcinoma of the colon. Of patients who have recurrences after curative resection of colon and rectal carcinomas, 80% do so within three years. Therefore, any follow-up plan should have a higher frequency of follow-up during these 3 years and a decreasing frequency thereafter. The present case is based on a 2-year follow-up and is free from any symptom/recurrence. References
Copyright 2009 - Journal of Cancer Research and Therapeutics The following images related to this document are available:Photo images[cr09080f3.jpg] [cr09080f1.jpg] [cr09080f2.jpg] |
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