**Question:** A girl presents with complaints of malena. On examination there are pigmented lesions involving her mouth and lips. Two of her sisters also had similar complaints. Which of the following is the most probable diagnosis -

A. Vitamin B12 deficiency
B. Sickle cell anaemia
C. Vitamin D deficiency
D. Lymphoma

**Core Concept:**

Malena refers to the presence of blood in the oropharynx or oral cavity, which is a sign of gastrointestinal bleeding. Pigmented lesions involving the mouth and lips might indicate a mucocutaneous manifestation of a systemic disease. The presence of similar complaints in two of her sisters suggests a familial or genetic cause.

**Why the Correct Answer is Right:**

The correct answer is **D** lymphoma, a group of cancerous disorders affecting the immune system, particularly lymphocytes. In this case, the patient's complaints and the presence of pigmented lesions in the mouth and lips are indicative of a systemic disorder. Lymphoma can cause gastrointestinal bleeding (malena) and mucocutaneous manifestations due to immune system dysfunction.

**Why Each Wrong Option is Incorrect:**

A. Vitamin B12 deficiency: While malena and pigmented lesions can occur in B12 deficiency, the familial history in this scenario is not consistent with a genetic disorder.
B. Sickle cell anaemia: Malena and pigmented lesions are not typically associated with sickle cell anaemia. Sickle cell anaemia is primarily characterized by pain crises, organ complications, and anaemia.
C. Vitamin D deficiency: Malena and pigmented lesions are not consistent with vitamin D deficiency. Vitamin D deficiency is related to bone pain, muscle weakness, and rickets.

**Clinical Pearl:**

In cases where patients present with malena and pigmented lesions, particularly in a familial context, one should consider lymphoma as a potential diagnosis. A thorough assessment of the patient's medical history and clinical examination can help narrow down the differential diagnosis. In this case, the familial history and clinical presentation led us to choose lymphoma as the most probable diagnosis.