WBR1489

Author	William J Gibson, Nikhil Panda
Exam Type	Surgery Shelf
Main Category	Lower Gastrointestinal tract
Sub Category	Management
Prompt	A 62 year old man presents to his primary care physician after noticing bright red blood in his stool for the past month. On review of systems, he describes occasional constipation and fatigue. Sigmoidoscopy reveals a 2.5 cm mass at the rectosigmoid junction. Pathological evaluation reveals a microsatellite-unstable adenocarcinoma that invades beyond the muscularis propria. Metastatic workup reveals no distant metastases or lymph node involvement. Which of the following best describes this tumor? Note:Stages refer to AJCC stages
Answer A	T2;N0;M0 - Stage I
Answer A Explanation	Invasion beyond the muscular propria indicates a T3 tumor. T2 tumors include those that have invaded, but not extended beyond the muscular propria.
Answer B	T2;N0;M0 - Stage IIA
Answer B Explanation	Invasion beyond the muscular propria indicates a T3 tumor. T2 tumors include those that have invaded, but not extended beyond the muscular propria.
Answer C	T2;N0;M0 - Stage IIB
Answer C Explanation	Invasion beyond the muscular propria indicates a T3 tumor. T2 tumors include those that have invaded, but not extended beyond the muscular propria.
Answer D	T3;N0;M0 - Stage I
Answer D Explanation	While this is a T3 tumor, it is not stage I. Once, a tumor has invaded beyond the muscular propria, it is deemed at least a Stage II tumor. In this case, because there is no lymph node involvement or metastases, the tumor is Stage IIA.
Answer E	T3;N0;M0 - Stage IIA
Answer E Explanation	A tumor that extends beyond the lamina propria is a T3 tumor, which translates to a Stage IIA tumor in the absence of lymph node involvement or detectable metastases.
Right Answer	E
Explanation	The patient in this this vignette has a T3 colorectal tumor. Colorectal tumors often bleed, particularly during bowel movements. Because bleeding occurs late in the digestive tract, the blood typically remains bright. Chronic bleeding from a colorectal tumor can cause anemia and fatigue, often the sole presenting symptom. In this case, the patient also experienced constipation, likely due to obstruction from the colorectal mass. A left-sided (descending colon) colorectal tumor is more likely to cause obstruction than a right sided colorectal tumor, due to the smaller lumen size on the left. The T-score of the tumor is determined by the depth of invasion of the tumor in relation to key micro-anatomic landmarks, as summarized in the Figure below. <img src="http://static.wikidoc.org/e/ee/WJG_Colorectal_Staging_copy.svg" /> The T-score is combined with information about the number of lymph nodes with tumor and the number of detectable metastases to assign a tumor stage (see Table below). Stage TNM Value 0 Tis, N0, M0 I T1, N0, M0; T2, N0, M0 IIA T3, N0, M0 IIB T4, N0, M0 IIIA T1, N1, M0; T2, N1, M0 IIIB T3, N1, M0; T4, N1, M0 IIIC Any T, N2, M0 IV Any T, Any N, M1 The stage of the tumor is of critical importance in determining the proper treatment for the tumor. Educational Objective: Invasion beyond the thick muscular layer of the bowel wall (muscularis propria) indicates a T3 tumor. References: AJCC (American Joint Committee on Cancer) Cancer Staging Manual, 7th ed, Edge, SB, Byrd, DR, Compton, CC, et al (Eds), Springer, New York 2010. p 143.
Approved	Yes
Keyword	Cancer, Colon, Colon cancer, Colorectal cancer, Rectal cancer, Rectum, Tumor, Staging, Tumor staging, Pathology
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