World Journal of Colorectal Surgery

Transcription

1 World Journal of Colorectal Surgery Volume 3, Issue Article 5 Implantation Of Sigmoid Adenocarcinoma Into Intersphincteric Anal Fistula Detected Three Months After Anterior Resection Hajir Nabi Daniel Kozman Bankstown-Lidcombe Hospital, New South Wales, Australia, hajirnabi@yahoo.com.au Bankstown-Lidcombe Hospital, New South Wales, Australia Copyright c 2014 The Berkeley Electronic Press. All rights reserved.

2 Implantation Of Sigmoid Adenocarcinoma Into Intersphincteric Anal Fistula Detected Three Months After Anterior Resection Hajir Nabi and Daniel Kozman Abstract Adenocarcinomas associated with perianal fistulas are very uncommon. Two different pathological pathways have been described to underlie their development. The more commonly described pathway relates to a chronic inflammatory process and subsequent dysplasia in the absence of any associated colorectal malignancy. The second and much more uncommon- mechanism results from the implantation of viable exfoliated tumour cells from a synchronous remote colorectal cancer. We report the case of a 68 year old man who had an adenocarcinoma identified in a perianal fistula three months after a high anterior resection performed for a pt3 N0 sigmoid adenocarcinoma. Pathological assessment of this deposit revealed that this had identical tumour characteristics to his original sigmoid adenocarcinoma confirming that exfoliated viable malignant cells had likely become implanted in a pre-existing clinically dormant perianal fistula. KEYWORDS: Implantation, Anal Fistula, Colorectal cancer

3 Nabi and Kozman: Implantation Of Sigmoid Adenocarcinoma Into Intersphincteric Anal 1 Implantation of sigmoid adenocarcinoma into intersphincteric anal fistula detected three months after anterior resection Hajir Nabi MBBS, FRACS Daniel Kozman MBBS, FRACS Bankstown-Lidcombe Hospital, New South Wales, Australia. Abstract Adenocarcinomas associated with perianal fistulas are very uncommon. Two different pathological pathways have been described to underlie their development. The more commonly described pathway relates to a chronic inflammatory process and subsequent dysplasia in the absence of any associated colorectal malignancy. The second and much more uncommon- mechanism results from the implantation of viable exfoliated tumour cells from a synchronous remote colorectal cancer. We report the case of a 68 year old man who had an adenocarcinoma identified in a perianal fistula three months after a high anterior resection performed for a pt3 N0 sigmoid adenocarcinoma. Pathological assessment of this deposit revealed that this had identical tumour characteristics to his original sigmoid adenocarcinoma confirming that exfoliated viable malignant cells had likely become implanted in a pre-existing clinically dormant perianal fistula. Introduction Adenocarcinomas arising in anal fistulas are rare. There are two mechanisms which have been identified which can lead to this unusual pathology. Firstly, Adenocarcinomas have been detected in the absence of any other colonic maliganancy 1-3. It has been postulated that the chronic inflammatory process which is associated with this otherwise benign pathology can give rise to dysplasia, and subsequent malignant transformation. Approximately 150 case reports of this uncommon pathology exist in the literature. Alternatively -and less commonly- exfoliated viable adenocarcinoma cells from a separate colorectal malignancy can implant into a concurrent anal fistula. Implantation of exfoliated colorectal adenocarcinoma into an anal fistula was first recognised and reported by Guiss 4 in Since then less than twenty cases of this rare phenomenon have been documented in English literature Through the same mechanism viable exfoliated colorectal adenocarcinoma cells have been implanted in staple lines, biopsy sites and haemorrhoidectomy wounds Case Report Produced by The Berkeley Electronic Press, 2013

4 2 World Journal of Colorectal Surgery Vol. 3, Iss. 4 [2014], Art. 5 A 68 year old man with few other medical co-morbidities presented to his general practitioner with a one month history of new onset constipation. A colonoscopy was arranged to evaluate this change in bowel habits. This revealed a moderately differentiated adenocarcinoma in the sigmoid colon 20cm from the anal verge. The tumour was hemi-circumferential, non-obstructing and extended over a distance of 5 cm. Staging computer tomography (CT) scans of the patient s chest, abdomen and pelvis revealed no evidence of disseminated disease (cm0) and no evidence of tumour perforation or local invasion. The patient subsequently underwent a laparoscopic high anterior resection, and made an unremarkable recovery. The procedure was uneventful with tumour handling kept to a minimum and no specimen perforation at the time of the resection. A povidoneiodine antiseptic washout of the rectal stump was performed prior to the creation of a double-stapled end-to-end anastomosis using a circular stapler to prevent the implantation of exfoliated tumour cells into the staple line. Histopathology confirmed the presence of a moderately differentiated sigmoid adenocarcinoma with mucinous foci and invasion through the muscularis propria for an estimated distance of up to 8mm (pt3c). Extramural venous invasion immediately deep to the tumour was noted. The resection was complete (R0) - with a 5cm distal clearance, 15cm proximal clearance and 27mm non-peritonealised circumferential clearance margin. Twenty-five lymph nodes were identified in the specimen and none were involved (pn0). No extramural tumour deposits were identified. The patient s pathology and imaging were presented at a multidisciplinary tumour board meeting and a subsequent referral was made for medical oncology outpatient review. The patient elected for no adjuvant therapy after having a discussion with the medical oncologists. On clinical review at three months post-resection the patient complained of perianal discomfort. On examination a perianal lump was identified and an examination under anaesthesia (EUA) was arranged. At the time of the EUA a 5mm nodule was identified on the perianal skin 2 cm from the anal verge. On probing, this lump was found to be a nodule at the external opening of an intersphincteric fistula in ano. The nodule was excised and sent for pathological review (although at the time the nodule was thought to represent an area of inflammation associated with the fistula). The fistula was subsequently laid open as minimal internal sphincter was involved. No other lesions were identified in the anal canal and there was no evidence of local recurrence at the anastomosis. Pathological examination of the perianal nodule confirmed the presence of a moderately differentiated adenocarcinoma- with identical pathological characteristics to the recently excised sigmoid carcinoma (Figure 1). The patient went on to have repeated imaging to exclude the presence of disseminated disease which included repeated CT chest, abdomen and pelvis as well as a proton emission tomography (PET) scan. The PET scan demonstrated intensely increased uptake in the region of the laid open fistula track, which was reported to be in keeping

5 Nabi and Kozman: Implantation Of Sigmoid Adenocarcinoma Into Intersphincteric Anal 3 with metastatic disease in the anal canal (Figure 2). No other recurrent or metastatic disease was demonstrated on the CT or PET scans. The patient went on to have an abdominoperineal resection (Figure 3) with final pathology confirming the presence of residual adenocarcinoma in the previously laid open fistula tract. The circumferential resection margins were complete (R0 resection). No lymph node involvement was identified. Discussion There are two types of adenocarcinomas which can develop in anal fistulas. Adenocarcinomas can arise de-novo in chronic anal fistulas or more rarely exfoliated viable colorectal tumour cells can implant into pre-existing fistula tracts. The first report of carcinoma originating in a chronic anal fistula was described by Rosser in The following diagnostic criteria for primary cancers from anal fistulas were established: 1. suffering from anal fistula for more than ten years, 2. indurations and severe pain at an anal fistula, 3. mucus secretion, 4. stoma aperture in the anal canal and anus crypt and 5. no tumour at the oral side of an anal fistula. The implantation of viable exfoliated colorectal cancer cells on staple lines, biopsy sites, other benign anal lesions and wounds is well established Likewise, viable malignant cells have been isolated from the bowel lumen, surgical gloves and instruments after colorectal surgery 23. Ours review of English literature identified fifteen other reports of exfoliated colorectal tumour cells leading to malignancy in pre-existing anal fistulas Like our case, authors of previous reports confirmed identical pathology between the deposits in the fistulas and the synchronous or metachronous colorectal cancers. All cases reported have been males. From the fifteen other case reports the site of the primary colorectal malignancy was recorded in the rectum in six, sigmoid colon in seven and left colon in two. Of those recorded: three were Dukes A cancers, seven were Dukes B and three were Dukes C. Interestingly no other disseminated disease was recorded in any reported cases. Seven of the cases like ours went on to have abdominoperineal resections, while eight patients had local resections (one of whom had neoadjuvant chemoradiotherapy prior to local excision). Only one of the fifteen other case reports documented that the patient had died from carcinomatosis 10 months after a local resection (original pathology Dukes C). Our case highlights the need for a high index of clinical suspicion when faced with unusual clinical presentations in people with recent colorectal cancer resections. The issues pertaining to the implantation of exfoliated malignant cells into benign tissue during colorectal cancer operations remains an area of concern for clinicians. Produced by The Berkeley Electronic Press, 2013

6 4 World Journal of Colorectal Surgery Vol. 3, Iss. 4 [2014], Art. 5 References 1. Yang BL, Shao WJ, Sun GD, Chen YQ, Huang JC. Perianal mucinous adenocarcinoma arising from chronic anorectal fistulae: a review from single institution. Int J Colorectal Dis 2009;24(9): Getz SB Jr, Oogh YD, Patterson RB, Kovalcik PJ. Mucinous adenocarcinoma developing in chronic anal fistula: report of two cases and review of literature. 3. Itah R, Werbin N, Skornick Y, Greenberg R. Anal mucinous adenocarcinoma arising in long standing fistula-in-ano. Harefuah 2008;147(2): Guiss RL. The implantation of cancer cells within a fistula in ano. Surgery 1954;3: Killingback M, Wilson E, Hughes ESR. Anal metastasis from carcinoma of the rectum and colon. Aust N Z J Surg 1965;34: Rollinson PD, Dundas SAC. Adenocarcinoma of sigmoid colon seeding into pre-existing fistula in ano. Br J Surg 1984;71: Thomas DJ, Thomas MR. Implantation metastasis from adenocarcinoma of sigmoid colon into fistula in ano. J R Soc Med 1992;85: Shinohara T, Hara H, Kato Y, Asano M, Nakazawa Y, Kato T, et al. Implantation of rectal cancer cells in a fistula in ano: report of a case. Surg Today 2001;31: Kouraklis G, Clinavou A, Kouvaraki M, Raftopoulos J, Karatzas G. Anal lesion resulting from implantation of viable tumour cells in a pre-existing anal fistula. A case report. Acta Chir Belg 2002;102: Ishiyama S, Inoue S, Kobayashi K, Sano Y, Kushida N, Yamazaki Y, Yanaga K. Implantation of rectal cancer in an anal fistula: Report of a case. Surg Today 2006;36: Hyman N, Kida M. Adenocarcinoma of the sigmoid colon seeding a chronic anal fistula: report of a case. Dis Colon Rectum 2003;46: Gupta R, Kay M, Birch DW. Implantation metastasis from adenocarcinoma of the colon into a fistula-in-ano: a case report. Can J Surg. 2005;48: Hamada M, Ozaki K, Iwata J et al. A case of rectosigmoid cancer metastasizing to a fistula in ano. Jpn J Clin Oncol 2005;35: Gravante G, Delogu D, Venditti D. Colosigmoid adenocarcinoma anastomotic recurrence seeding into a transsphincteric fistula-in-ano: a clinical report and literature review. Surg Laparosc Endosc Percutan Tech. 2008;18: Benjelloun EB, Aitalalim S, Chbani L, Mellouki I, Mazaz K, Aittaleb K. Rectosigmoid adenocarcinoma revealed by metastatic anal fistula. The visible part of the iceberg: a report of two cases with literature review. World J Surg Oncol. 2012; 10: Sandiford N, Prussia PR, Chiappa A, Zbar AP. Synchronous mucinous adenocarcinoma of the rectosigmoid seeding onto a pre-existing anal fistula. Int Semin Surg Oncol. 2006;3: Zbar AP, Shenoy RK. Synchronous carcinoma of the sigmoid colon and a perianal fistula. Dis Colon Rectum. 2004;47: Wakatsuki K, Oeda Y, Isono T, Yoshioka S, Nukui Y, Yamazaki K, Nabeshima S, Miyazaki M. Adenocarcinoma of the rectosigmoid colon seeding into pre-existing anal fistula. Hepatogastroenterology. 2008;55(84):

7 Nabi and Kozman: Implantation Of Sigmoid Adenocarcinoma Into Intersphincteric Anal Gertsch P, Baer HU, Kraft R et al. Malignant cells are collected on circular staplers. Dis Colon Rectum 1992;35: Basha G, Ectors N, Penninckx F et al. Tumor cell implantation after colonoscopy with biopsies in a patient with rectal cancer: a report of a case. Dis Colon Rectum 1997;40: Hsu TC, Lu IL. Implantation of adenocarcinoma on haemorrhoidectomy wound. Int J Colorectal Dis. 2007;22: Rosser C. The etiology of anal cancer. Am J Surg 1931;11: Skipper D, Cooper AJ, Marston JE et al. Exfoliated cells and in vitro growth in colorectal cancer. Br J Surg Figure1. Histopathology slides confirming that the implanted area in the anal fistula was identical to the sigmoid adenocarcinoma excised 3 months earlier. Produced by The Berkeley Electronic Press, 2013

8 6 World Journal of Colorectal Surgery Vol. 3, Iss. 4 [2014], Art. 5 Figure 2. PET scan demonstrating increased uptake in region of laid open fistula track (indicated by white arrow). Figure 3. Pre-operative photograph with patient in lithotomy position showing the area of malignancy in the laid open perianal fistula (indicated by white arrow).