A Case Of Multiple Advanced Colon Cancers With Spontaneous Regression Of Only One Lesion After Biopsy: A Case Report And Literature Review
Nakano, Y., Nishikawa, G., Degawa, K., Moriyoshi, K., Kuriyama, K., Watanabe, Y., & Miyamoto, S. (2025). A case of multiple advanced colon cancers with spontaneous regression of only one lesion after biopsy: a case report and literature review. Clinical journal of gastroenterology, 18(3), 393–398. https://doi.org/10.1007/s12328-025-02106-1
View Original Source →Abstract
A 90-year-old man underwent a colonoscopy due to abdominal distension, revealing half-circumferential Type 2 advanced cancers in the ascending and transverse colon. No distant metastasis was detected, and 3 months later, laparoscopic extended right hemicolectomy was performed for both lesions. Pathological examination revealed ulcers and mucus retention in the ascending colon lesion without tumor components. A small number of signet ring cell-like tumor cells were found in the regional lymph node of the ascending colon, while well-to-moderately differentiated tubular adenocarcinoma was observed on the serosal surface in the transverse colon. Tumor regression was observed in the ascending colon cancer and lymph-node metastasis. Mismatch repair (MMR) protein immunostaining was conducted on biopsy tissues from both lesions. The ascending colon lesion showed weak positivity for MLH1, positivity for MSH2 and MSH6, and negativity for PMS2, indicating MMR deficiency, whereas the transverse colon lesion showed positivity for all of them, indicating MMR-proficient tumor. This is the first case report of multiple advanced colon cancers, where only one lesion exhibited spontaneous regression after biopsy, suggesting a potential link between MMR deficiency and the spontaneous regression of colorectal cancer.
Case Details
Disease Location
Colon, lymph nodes
Personal Characteristics
90-year-old man. History of surgically resected laryngeal cancer, superficial esophageal cancer, deep vein thrombosis, and pulmonary embolism, for which he was taking apixaban
Clinical Characteristics
Blood tests revealed iron deficiency anemia. Colonoscopy revealed a half-circumferential (40 mm in size) type 2 advanced cancer with mucus on the surface (biopsy: moderately differentiated adenocarcinoma) in the ascending colon, and a similar lesion (biopsy: well-to-moderately differentiated adenocarcinoma) in the transverse colon. CT scans showed wall thickening in the ascending and transverse colon, with enlarged lymph nodes in the vicinity. PET-CT revealed accumulation of 18-fdg. 3 months after the endoscopic examination, laparoscopic extended right hemicolectomy was performed for both lesions. A d2 lymph node dissection was performed for the ascending colon lesion. Immunostaining of the ascending colon lesion showed mmr deficiency (high-frequency microsatellite instability [msi]) and an mmr-proficient tumor in the transverse colon lesion. The transverse colon lesion tested positive for nras g12d mutations
Remission Characteristics
Tumor regression was noted in the ascending colon and lymphnode metastasis.
Treatment & Mechanisms
Clinical Treatment
Biopsy, laparoscopic right hemicolectomy, d2 lymph node dissection