**Question:** Adrenocortical carcinoma of size 6cm without invading surrounding structure is classified as:

A. T3 stage
B. T2 stage
C. T3 stage with N1 or M1
D. T2 stage

**Correct Answer:** D. T2 stage

**Core Concept:**
Adrenocortical carcinomas are malignant tumors originating from the adrenal cortex. The TNM staging system is commonly used to stage tumors, including adrenocortical carcinoma. In this system, T refers to tumor size and involvement of surrounding structures, N refers to nodal involvement, and M refers to distant organ involvement.

**Why the Correct Answer is Right:**
The correct answer is T2 stage because an adrenocortical carcinoma with a size of 6cm does not meet the criteria for T3 stage, which would require the tumor to extend beyond the adrenal gland capsule. In T2 stage, tumors are limited to the adrenal gland but have a diameter greater than 6cm. This staging helps guide treatment options, prognosis, and patient management.

**Why Each Wrong Option is Incorrect:**
A. T3 stage (6cm tumor size) would require invasion of surrounding structures. Since the tumor is limited to the adrenal gland, it is not T3.
B. T2 stage is correct (as explained above).
C. T3 stage with N1 or M1 requires nodal or distant organ involvement, which is not present in this case.

**Clinical Pearl:**
Knowing the TNM staging of adrenocortical carcinoma is crucial for appropriate treatment planning and prognosis estimation. T2 stage tumors are managed differently from T3 stage tumors, emphasizing the importance of accurate staging classification.