**Question:** Banka's lesion is seen in

A. Skin
B. Liver
C. Kidney
D. Lung

**Core Concept:** Banka's lesion refers to a specific pattern of skin lesions that occur in patients with severe hypothyroidism or myxedema. This clinical manifestation is named after Dr. R.C. Banka, who first described it. In hypothyroidism, there is a deficiency of thyroid hormones, which leads to various systemic effects, including skin changes.

**Why the Correct Answer is Right:** Banka's lesion is primarily seen in skin due to the effects of hypothyroidism on skin structure and function. Thyroid hormones, particularly triiodothyronine (T3), play a crucial role in maintaining skin homeostasis, pigmentation, and elasticity. Hypothyroidism leads to decreased production of T3 and triiodothyronine-binding proteins, causing a cascade of changes in skin structure and function. These changes result in the clinical manifestations seen in Banka's lesion.

**Why Each Wrong Option is Incorrect:**

A. Liver (option B): Hypothyroidism can affect the liver, causing elevated transaminase levels and cholestasis. However, Banka's lesion is not a liver manifestation but rather skin-related.

B. Kidney (option C): Hypothyroidism can affect the kidney, leading to electrolyte imbalances and other renal manifestations. However, Banka's lesion is a skin manifestation and not a renal one.

D. Lung (option D): Although hypothyroidism can affect the lungs, leading to respiratory issues, Banka's lesion is not a pulmonary manifestation but rather a skin manifestation.

**Clinical Pearl:** Hypothyroidism can present with a range of clinical manifestations, including skin changes like hypopigmentation, dryness, and cold intolerance, as well as systemic effects like weight gain, fatigue, and cold intolerance.

**Correct Answer:** Banka's lesion (option A) is a skin manifestation resulting from the effects of hypothyroidism on skin structure and function. It demonstrates the importance of maintaining euthyroidism for proper skin health and functioning.