[…] of a phase III randomized trial of the European Organization for Research and Treatment of Cancer radiotherapy and gastrointestinal cooperative groups. [link.springer.com]

[…] carcinomas elsewhere (Dis Colon Rectum 1999;42:1200) Case reports 69 year old man with perianal basal cell carcinoma (Indian J Dermatol 2010;55:178) 88 year old woman with polypoid basal cell carcinoma on the perianal region (J Dermatol 2004;31:51) Treatment [pathologyoutlines.com]

Successful treatment of basaloid squamous cell carcinoma in the rectosigmoid colon: A case report and review of literature. Lee TG, Yoon SM, Kim MJ. Lee TG, et al. World J Clin Cases. 2020 Jul 26;8(14):3057-3063. doi: 10.12998/wjcc.v8.i14.3057. [pubmed.ncbi.nlm.nih.gov]

Oral Surg Oral Med Oral Pathol 30:308–315 CrossRef Google Scholar Woolgar JA, Triantafyllou A (2009) Pitfalls and procedures in the diagnosis of oral and oropharyngeal squamous cell carcinoma and a review of the role of pathology in prognosis. [link.springer.com]

[…] at all sites (Am J Dermatopathol 1996;18:371, Rev Gastroenterol Mex 2013;78:52) Nodular subtype most common in this location Essential features Rare perianal malignancy identical to basal cell carcinoma of skin Sites Perianal skin (not anus proper) Pathophysiology [pathologyoutlines.com]