INI-CET 2025 - Surgery Practice Questions

Q: A 65-year-old patient undergoes colonoscopy for altered bowel habits. A 6 cm colonic mass is biopsied and histopathology shows adenocarcinoma confined to the mucosa with no lymph node or distant metastasis. What is the most appropriate TNM stage of this tumor?

Stage 0. ### **Explanation** The correct answer is **Stage 0**. #### **1. Why Stage 0 is Correct** In the TNM staging of colorectal cancer, the depth of invasion is the primary determinant of the 'T' stage. * **Carcinoma in situ (Tis):** This is defined as cancer cells confined to the **mucosa** (epithelium or lamina propria) without extension through the **muscularis mucosae** into the submucosa. * Because the colonic mucosa lacks lymphatic channels (which begin in the submucosa), tumors confined to the mucosa have essentially **zero risk of regional lymph node metastasis**. * According to the AJCC staging system, **Tis N0 M0** is classified as **Stage 0**. #### **2. Why Other Options are Incorrect** * **Stage I (T1-T2 N0 M0):** Requires invasion into the **submucosa** (T1) or the **muscularis propria** (T2). * **Stage II (T3-T4 N0 M0):** Occurs when the tumor invades through the muscularis propria into the subserosa (T3) or perforates the visceral peritoneum/invades adjacent organs (T4), but without nodal involvement. * **Stage III (Any T, N1-N2 M0):** This stage is defined by the presence of **regional lymph node metastasis**, regardless of the depth of T invasion. #### **3. High-Yield Clinical Pearls for INI-CET** * **The "No Lymphatics" Rule:** Unlike the stomach or esophagus, the colonic lamina propria has no lymphatic vessels. Therefore, "intramucosal carcinoma" in the colon is biologically equivalent to carcinoma in situ. * **Management:** Most Stage 0 lesions can be managed via **endoscopic mucosal resection (EMR)** or polypectomy rather than formal colectomy, provided margins are clear. * **TNM Staging Quick Recall:** * **T1:** Submucosa * **T2:** Muscularis propria * **T3:** Subserosa/Pericolonic fat * **T4:** Perforation of serosa or invasion of other organs.

Q: Cleft lip primary muscle repair is required in which of the following muscles?

Orbicularis oris. ***Orbicularis oris*** - The **orbicularis oris** muscle forms the main sphincter of the mouth and is interrupted in a cleft lip. Repair involves meticulous anatomical realignment of this muscle for correct function and appearance. - Dysfunction of this muscle in unrepaired cleft lip leads to **vermilion deficiency**, **cupid's bow distortion**, and poor feeding/speech. *Orbicularis oculi* - This muscle surrounds the eye and is responsible for blinking and closing the eyelid; it is not primarily affected in a standard cleft lip. - Though part of the facial musculature, its involvement is secondary, mainly due to potential nerve injury during extensive **craniofacial procedures**, not cleft lip repair. *Levator palpebrae superioris* - This muscle elevates the upper eyelid and is innervated by the **oculomotor nerve (CN III)**. It is not involved in cleft lip pathology or repair. - Its function is essential for vision, and damage results in **ptosis**, a concern unrelated to primary lip closure. *Masseter* - The masseter is a powerful muscle of mastication, innervated by the **trigeminal nerve (CN V)**. It is located in the cheek and is not part of the required functional repair for a cleft lip. - Its primary role is in **jaw closure (chewing)**, and its integrity is preserved during standard cleft lip repair procedures.

Question 1

A 65-year-old patient undergoes colonoscopy for altered bowel habits. A 6 cm colonic mass is biopsied and histopathology shows adenocarcinoma confined to the mucosa with no lymph node or distant metastasis. What is the most appropriate TNM stage of this tumor?

Accepted Answer

Stage 0

Answer

Stage II

Answer

Stage III

Answer

Stage I

Question 2

A patient has burns involving the face, both upper limbs and front of the chest. What is the percentage of burns involved?

Accepted Answer

30 to 37

Answer

25 to 48

Answer

27 to 30

Answer

38 to 42

Question 3

Cleft lip primary muscle repair is required in which of the following muscles?

Accepted Answer

Orbicularis oris

Answer

Levator palpebrae superioris

Answer

Orbicularis oculi

Answer

Masseter

INI-CET 2025 — Surgery