**Question:** Which investigation is not done in FIGO staging of CA cervix:

A. Endoscopy
B. Biopsy
C. Abdominal ultrasound
D. Brain imaging

**Core Concept:** The FIGO (International Federation of Gynecology and Obstetrics) staging system is a widely accepted method for classifying and staging cervical cancer. Staging involves evaluating the tumor size, depth of invasion, and extent of lymph node and distant organ involvement.

**Why the Correct Answer is Right:** In the FIGO staging system, only Cervical Biopsy (Option B) is not considered as a routine investigation. A biopsy is usually performed to confirm the diagnosis of cervical cancer and to determine the histopathological (tissue examination) characteristics of the tumor, such as grade, type, and margin involvement. However, it is not used for staging purposes.

**Why Each Wrong Option is Incorrect:**

A. Endoscopy (Option A) is occasionally performed for assessing the primary tumor, particularly in cases where visualization is difficult during biopsy. However, it is not a routine component of staging.

B. Brain imaging (Option D) is not performed in cervical cancer staging as cervical cancer is primarily a disease of the cervix and upper vagina. Brain imaging is only necessary in cases of suspected distant organ involvement.

C. Abdominal ultrasound (Option C) is used to assess the involvement of pelvic lymph nodes, ovaries, and other abdominal organs. It is a crucial imaging modality in determining pelvic stage of cervical cancer.

**Clinical Pearl:** In cervical cancer staging, the most essential investigations are pelvic examination, Pap smear, colposcopy, and pelvic imaging (CT or MRI) for pelvic staging. Brain imaging is only necessary in selected cases with suspected distant organ involvement. Histopathology (biopsy) is essential for confirming the diagnosis and determining the histopathological characteristics of the tumor.