A rectal carcinoma, including primary an adenosquamous and a squamous cell carcinoma (SCC), is a very rare disease, accounting for 0.025% to 0.20% of all large-bowel malignant tumors. Because SCCs have a higher mortality than adenosquamous carcinomas, determining whether the primary rectal cancer exhibits an adenomatous component or a squamous component is important. While differentiating between these 2 components, especially in poorly differentiated rectal cancer, is difficult, specific immunohistochemical stains enable accurate diagnoses. Here, we report the use of immunohistochemical stains to distinguish between the adenomatous and the squamous components in 2 patients with low rectal cancer, a 58-year-old man and a 73-year-old woman, who were initially diagnosed using the histopathologic results for a poorly differentiated carcinoma. These data suggest that using these immunohistochemical stains will help to accurately diagnose the type of rectal cancer, especially for poorly differentiated carcinomas, and will provide important information to determine the proper treatment for the patient.

Citations

Citations to this article as recorded by  

• Cerebral metastasis from anal squamous cell carcinoma: A case report and literature review
  Elena Popa, Vanesa Tomatis, Esther Quick, Paul Mitchell, Chrisovalantis Tsimiklis, Annika Mascarenhas
  Oncology Letters.2025; 30(1): 1.     CrossRef

An adenosquamous carcinoma is a malignancy that has both glandular and squamous histologic components. Both components are malignant and have potential to metastasize. An adenosquamous carcinoma of the large bowel is rare, and its clinicopathologic behavior is not fully understood. It is reported to be more aggressive and have a worse prognosis when it is compared with an adenocarcinoma alone. We present a case of an adenosquamous carcinoma in the ascending colon which was laparoscopically resected and followed by adjuvant chemotherapy.

Citations

Citations to this article as recorded by  

• Colorectal adenosquamous carcinoma: clinicopathologic analysis of two large cohorts and literature review confirm poor prognosis and reveal prognostic aspects
  Raul S Gonzalez, Rachel K Horton, Xuchen Zhang, Rondell P Graham, Teri A Longacre, Anupamjit Mehrotra, Daniela S Allende, Kelsey E McHugh, Jinru Shia, Maria Westerhoff, Amitabh Srivastava, Wei Chen, Jennifer Vazzano, Paul E Swanson, Deyali Chatterjee, Has
  Histopathology.2025; 86(7): 1064.     CrossRef
• Presentation, treatment, and prognosis of colorectal adenosquamous carcinoma: A contemporary analysis of the surveillance, epidemiology, and end results database
  Adil H. Khan, Xiang Gao, Paolo Goffredo, Amanda R. Kahl, Alan F. Utria, Mary E. Charlton, Sajida Ahad, Imran Hassan
  The American Journal of Surgery.2022; 223(5): 957.     CrossRef
• PRIMARY ADENOSQUAMOUS CARCINOMA OF COLON – A RARE CASE DIAGNOSED ON HISTOPATHOLOGY
  Shivani Parikh, Nisha Raval
  PARIPEX INDIAN JOURNAL OF RESEARCH.2022; : 29.     CrossRef
• Atypical Expression of CK7 and CK20 in Adenosquamous Carcinoma, Colon—a Rare Case
  Tarun Kumar, Avinash Singh, Jitendra Singh Nigam, Jagjit Kumar Pandey, Subhash Kumar
  Journal of Gastrointestinal Cancer.2021; 52(2): 780.     CrossRef
• Adenosquamous carcinoma of the right colon: A case report and review of the literature
  Omar Toumi, Badii Hamida, Manel Njima, Amal Bouchrika, Houssem Ammar, Amira Daldoul, Sonia Zaied, Sadok Ben Jabra, Rahul Gupta, Faouzi Noomen, Khadija Zouari
  International Journal of Surgery Case Reports.2018; 50: 119.     CrossRef
• Primary Colon Adenosquamous Carcinoma in a Patient With Lynch Syndrome
  Virginia E. Duncan, Shuko Harada, Todd M. Stevens
  International Journal of Surgical Pathology.2016; 24(7): 653.     CrossRef
• Clinicopathological characteristics, diagnosis, treatment, and outcomes of primary gastric adenosquamous carcinoma
  Haining Chen, Chaoyong Shen, Rui Yin, Yuan Yin, Jiaju Chen, Luyin Han, Bo Zhang, Zhixin Chen, Jiaping Chen
  World Journal of Surgical Oncology.2015;[Epub]     CrossRef
• Adenosquamous Carcinoma in Distal Transverse Colon in a 72-Year-Old Female Patient
  Kang Ryun Moon, Jong Seok Ju, Hee Seok Moon, Sun Hyung Kang, Jae Kyu Seong, Hyun Yong Jeong
  Journal of the Korean Geriatrics Society.2014; 18(1): 30.     CrossRef