NEET-PG 2020 - Pathology Practice Questions

Q: Patient presented with diarrhoea, poor appetite and malabsorption. His duodenal biopsy was taken which showed crypt hyperplasia, villi atrophy and infiltration of CD8+ T cells in the epithelium. What is the likely diagnosis of the patient?

Celiac disease. ***Celiac disease*** - The combination of **diarrhoea**, **malabsorption**, **villi atrophy**, **crypt hyperplasia**, and **CD8+ T-cell infiltration** in the duodenal epithelium is pathognomonic for celiac disease [1]. - This condition is triggered by **gluten ingestion**, leading to an immune-mediated enteropathy [1], [3]. *Whipple disease* - Characterized by **malabsorption**, fever, arthralgia, and neurological symptoms [2]. - Histologically, it shows **foamy macrophages** containing PAS-positive material (Tropheryma whipplei) in the lamina propria, not primarily CD8+ T-cell infiltration [2]. *Environmental enteropathy* - Also known as tropical enteropathy, it causes **villi atrophy** and malabsorption, particularly in individuals living in areas with poor sanitation. - However, the prominent feature is often a diffuse inflammatory infiltrate, and specific **CD8+ T-cell infiltration** in the epithelium is not as specific as in celiac disease. *Pancreatitis* - Presents with **abdominal pain**, nausea, and vomiting, and can lead to malabsorption due to pancreatic enzyme insufficiency. - Histology of the duodenum would typically be normal, as the pathology primarily involves the **pancreas**, not the duodenal mucosa itself.

Q: A newborn baby presented with a failure to pass meconium in the immediate postnatal period. The pediatrician also notices visible yet ineffective peristalsis, and abdominal distention. A radiological contrast enema demonstrated a narrow conical segment and a dilated proximal bowel. A diagnosis of Hirschsprung disease was made. Which of the following is a cause of the condition in the patient?

Failure of migration of neural crest cells. ***Failure of migration of neural crest cells*** - Hirschsprung disease is characterized by the **absence of ganglion cells** (specifically **Auerbach's and Meissner's plexuses**) in the distal bowel. - This aganglionosis results from the **failure of neural crest cells to migrate** completely into the intestinal wall during embryonic development. *Persistence of embryonic structures in the bowel wall* - This mechanism is associated with conditions like **Meckel's diverticulum**, where a remnant of the **vitelline duct** persists. - It does not explain the absence of ganglion cells or the functional obstruction seen in Hirschsprung disease. *Congenital obstruction due to external factors* - This would involve conditions such as an **annular pancreas**, **bands**, or **malrotation with volvulus**, creating a physical barrier. - Hirschsprung disease is a **functional obstruction** due to neuromuscular dysfunction, not an external compression or blockage. *Abnormal peristalsis due to neural dysfunction* - While there is abnormal peristalsis, the underlying cause is not just **"neural dysfunction"** in a general sense, but specifically the **absence of entire ganglion cell plexuses** within the bowel wall. - This option is too broad and doesn't pinpoint the precise developmental defect.

Q: Transplantation between identical twins-

Isograft. ***Isograft*** - An **isograft** refers to a transplant between **genetically identical individuals**, such as identical twins, thus minimizing immune rejection [1]. - Due to the identical genetic makeup, the recipient's immune system will not recognize the transplanted tissue as foreign, making **immunosuppression unnecessary** [1]. *Xenograft* - A **xenograft** involves transplantation of tissues or organs between **different species**, for example, from a pig to a human. - These grafts typically face severe and rapid **immune rejection** due to significant genetic differences between the donor and recipient species. *Autograft* - An **autograft** is a transplant of tissue from **one part of an individual's body to another part of the same individual**. - This type of graft has no risk of rejection as the tissue is genetically identical to the recipient's own tissue [2]. *Allograft* - An **allograft** is a transplant between **genetically non-identical individuals of the same species**, such as between two non-twin humans. - These grafts always require **immunosuppressive therapy** to prevent rejection due to genetic differences, though rejection rates vary based on HLA matching [1].

Question 1

Patient presented with diarrhoea, poor appetite and malabsorption. His duodenal biopsy was taken which showed crypt hyperplasia, villi atrophy and infiltration of CD8+ T cells in the epithelium. What is the likely diagnosis of the patient?

Accepted Answer

Celiac disease

Answer

Whipple disease

Answer

Environmental enteropathy

Answer

Pancreatitis

Question 2

A newborn baby presented with a failure to pass meconium in the immediate postnatal period. The pediatrician also notices visible yet ineffective peristalsis, and abdominal distention. A radiological contrast enema demonstrated a narrow conical segment and a dilated proximal bowel. A diagnosis of Hirschsprung disease was made. Which of the following is a cause of the condition in the patient?

Accepted Answer

Failure of migration of neural crest cells

Answer

Persistence of embryonic structures in the bowel wall

Answer

Congenital obstruction due to external factors

Answer

Abnormal peristalsis due to neural dysfunction

Question 3

Transplantation between identical twins-

Accepted Answer

Isograft

Answer

Xenograft

Answer

Autograft

Answer

Allograft

NEET-PG 2020 — Pathology