Colon medullary adenocarcinoma

초록

Colon adenocarcinoma is a relatively common and well-recognized typical histologic entity. However, a newly recognized subtype, namely colon medullary adenocarcinoma (MADC), recently has been characterized. MADC is a rare subtype of colorectal cancer making up less than 0.1% of all colorectal malignant tumors. This type of adenocarcinoma is a unique histologic subtype of almost always microsatellite unstable and has a strong association with hereditary non-polyposis colorectal cancer (HNPCC or Lynch syndrome). There are few reports in the literature, but it has been shown that MADC has a female tendency and is frequently located at the proximal parts of the colon with low incidence of lymph node involvement and distant metastases. In this report, we present a case of medullary adenocarcinoma of the transverse colon in a 58-year-old female patient who has a very strong family history of colorectal cancer. A 58-year-old female with past history of endometrial cancer came to our hospital for her annual health checkup. She had undergone laparoscopic assisted vaginal hysterectomy for early stage of endometrial adenocarcinoma approximately 12 years prior to this visit and had a powerful family history of colorectal cancer in first-degree relatives (her father, sister and brother). The colonoscopy revealed a 4.0 x 3.5 cm ulcerating intraluminal mass with easy touch bleeding located in the distal one third of the transverse colon. The pathological diagnosis obtained by colonoscopic biopsy showed well differentiated adenocarcinoma. Blood carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9) level were 0.77 ng/mL and 40.88 U/mL, respectively. An abdominal computed tomography displayed irregular wall thickened lesion with pericolic infiltration at the distal transverse colon but, no regional lymph node involvement or distant metastases. These findings led to a diagnosis of clinical T3N0M0 colon cancer according to the UICC TNM classification. The patient under