NEET-PG 2025 - Internal Medicine PYQs Practice Questions

Q: A 40-year-old man presents with discomfort in one of his joints. Synovial fluid aspiration reveals rhomboid-shaped, positively birefringent crystals under polarized light microscopy. Which of the following is the most likely diagnosis?

C. Pseudogout. ### Pseudogout - Pseudogout, or **Calcium Pyrophosphate Dihydrate (CPPD) crystal deposition disease**, is classically identified by the presence of **rhomboid-shaped** crystals [1]. - These CPPD crystals exhibit **positive birefringence** under polarized light microscopy, a distinguishing feature from gout [1]. *Gout* - Gout is characterized by monosodium urate (MSU) crystals, which are **needle-shaped**, not rhomboid [1]. - MSU crystals show **strong negative birefringence**, appearing yellow when aligned parallel to the compensator axis (Yellow parallel) [1]. *Rheumatoid arthritis* - The primary diagnostic finding in rheumatoid arthritis (RA) synovial fluid is **inflammatory changes** (high WBC count, mostly neutrophils) and not the presence of crystals. - RA is associated with **RF** and **anti-CCP antibodies** and primarily affects smaller joints symmetrically. *Osteoarthritis* - Osteoarthritis (OA) synovial fluid is typically **non-inflammatory**, appearing viscous with a low white blood cell count (<2000 cells/mm³). - OA is a degenerative joint disease defined by **cartilage loss** and **osteophyte formation**, not crystal deposition [1]. [Practice more Internal Medicine PYQs on OnCourse]

Q: A patient presents with orange-colored tonsils. Laboratory investigations reveal triglyceride level of 140 mg/dL and HDL cholesterol of 5 mg/dL. What is the most likely diagnosis?

Tangier disease. ***Tangier disease*** - This condition is a rare genetic disorder characterized by a mutation in the **ATP-binding cassette transporter A1 (ABCA1)** gene, leading to accelerated catabolism of HDL. - The clinical hallmarks are extremely low **HDL cholesterol** (often < 5 mg/dL) and the accumulation of cholesterol esters in macrophages, resulting in enlarged, characteristic **orange-colored tonsils** [1]. *Familial hypercholesterolemia* - Caused by defects in the **LDL receptor** or ApoB, resulting in severely elevated **LDL cholesterol** levels and premature atherosclerosis [1]. - It typically presents with tendon xanthomas and arcus senilis, but does not cause extremely low HDL or visible changes in the tonsils. *Type I hyperlipoproteinemia* - This type is characterized by functional deficiency of **lipoprotein lipase (LPL)** or its cofactor ApoC-II, leading to massive accumulation of **chylomicrons** in the plasma. - The primary finding is severe **hypertriglyceridemia** (often > 1000 mg/dL), leading to eruptive xanthomas and pancreatitis; HDL levels are not the primary diagnostic feature. *Abetalipoproteinemia* - Caused by a defect in the **microsomal triglyceride transfer protein (MTP)**, preventing the synthesis of ApoB-containing lipoproteins (chylomicrons, VLDL, LDL) [1]. - It presents with severe fat malabsorption, neurological deficits due to Vitamin E deficiency, and **acanthocytosis** (spiculated RBCs), rather than tonsillar changes. [Practice more Internal Medicine PYQs on OnCourse]

Q: A person with jaundice presented with a history of bleeding and symptoms normalised after giving Vitamin K injection. The probable cause is?

Biliary obstruction. ***Biliary obstruction*** - **Biliary obstruction** (Cholestasis) prevents the flow of bile into the duodenum, impairing the absorption of **fat-soluble vitamins** (A, D, E, K) [1]. - **Vitamin K** deficiency leads to impaired synthesis of **coagulation factors II, VII, IX, and X** in the liver, causing a coagulopathy (bleeding tendency) that is corrected by parenteral Vitamin K administration [2]. *Alpha antitrypsin deficiency* - This typically causes liver disease (cirrhosis) and emphysema, but the bleeding issues are due to general hepatic synthetic failure, meaning the coagulopathy would usually be **refractory to simple Vitamin K injection** [1]. - The deficiency is mainly linked to **panacinar emphysema** and pediatric/adult liver failure presentations, not primarily a **Vitamin K-responsive coagulopathy**. *Autoimmune hepatitis* - This condition causes chronic inflammation and destruction of hepatocytes, leading to liver failure and cirrhosis; the resulting coagulopathy is due to **synthetic dysfunction**. - Coagulopathy from severe autoimmune hepatitis is typically **not fully corrected** by Vitamin K injection alone, requiring fresh frozen plasma (FFP) if bleeding is severe. *Factor XI deficiency* - This is a rare, **autosomal recessive** congenital deficiency (Hemophilia C) not usually associated with jaundice or liver disease. - The bleeding tendency is **not due to Vitamin K malabsorption** or deficiency, and thus would not be corrected by Vitamin K injection. [Practice more Internal Medicine PYQs on OnCourse]

Q: A 20-year-old man presents with chronic back pain that is worse in the morning and improves with physical activity. He also has a history of anterior uveitis. A lumbar spine X-ray shows no abnormalities. Which of the following is the most appropriate next investigation for early diagnosis?

MRI sacroiliac joints. The presentation (inflammatory back pain improving with activity, and anterior uveitis) strongly suggests **Ankylosing Spondylitis (AS)** [1]. MRI is the **most sensitive imaging modality** for early diagnosis, as it can detect acute, reversible inflammatory changes (like **bone marrow edema**) in the sacroiliac joints before they are visible on X-ray [1]. CT is superior for visualizing **bony changes** like erosions or fusion but is significantly less sensitive than MRI for detecting active **bone marrow inflammation** in the early stages of sacroiliitis [1]. X-ray of the spine is usually performed after SI joint films but will often be **normal in early disease** (as suggested by the clinical case, where lumbar X-ray was negative) [1]. Radiographic changes like squaring of vertebrae or **syndesmophytes** only appear much later in the disease course, making it inadequate for *early* diagnosis [1]. Bone scintigraphy (bone scan) is a **non-specific** test that shows increased uptake but has poor anatomical resolution for assessing the sacroiliac joint specifically [1]. [Practice more Internal Medicine PYQs on OnCourse]

Q: A 16-year-old boy presents with jaundice and splenomegaly. His father had a similar illness during adolescence. MCHC : high? What is the most likely diagnosis?

B. Hereditary spherocytosis. ***Hereditary spherocytosis*** - The presentation of **jaundice**, **splenomegaly**, strong **family history** (autosomal dominant pattern), and an elevated **MCHC** is classic for Hereditary Spherocytosis. [1] - Elevated MCHC is a key diagnostic feature due to mild cellular dehydration in the characteristic **spherocytes**. [1] *IDA* - **Iron Deficiency Anemia (IDA)** is typically microcytic and hypochromic, leading to a **low MCHC**, not high. - Symptoms of IDA include fatigue and pallor, generally without marked jaundice or splenomegaly unless severe. *Thalassemia major* - **Thalassemia major** presents with severe microcytic, hypochromic anemia (low MCHC) usually evident in early infancy, requiring regular transfusions. - While it causes jaundice and hepatosplenomegaly, it is characterized by severe bone changes and a very low MCHC. *AIHA* - **Autoimmune Hemolytic Anemia (AIHA)** typically presents acutely or subacutely and often responds to immunosuppression (e.g., steroids). - Unlike Hereditary Spherocytosis, AIHA generally does not present with a positive **family history** and the primary lab finding is a positive **Direct Antiglobulin Test (DAT)**, not specifically high MCHC. [Practice more Internal Medicine PYQs on OnCourse]

Question 1

A 40-year-old man presents with discomfort in one of his joints. Synovial fluid aspiration reveals rhomboid-shaped, positively birefringent crystals under polarized light microscopy. Which of the following is the most likely diagnosis?

Accepted Answer

C. Pseudogout

Answer

A. Gout

Answer

B. Rheumatoid arthritis

Answer

D. Osteoarthritis

Question 2

A patient presents with orange-colored tonsils. Laboratory investigations reveal triglyceride level of 140 mg/dL and HDL cholesterol of 5 mg/dL. What is the most likely diagnosis?

Accepted Answer

Tangier disease

Answer

Abetalipoproteinemia

Answer

Type I hyperlipoproteinemia

Answer

Familial hypercholesterolemia

Question 3

A person with jaundice presented with a history of bleeding and symptoms normalised after giving Vitamin K injection. The probable cause is?

Accepted Answer

Biliary obstruction

Answer

Autoimmune hepatitis

Answer

Alpha antitrypsin deficiency

Answer

Factor XI deficiency

Question 4

A 20-year-old man presents with chronic back pain that is worse in the morning and improves with physical activity. He also has a history of anterior uveitis. A lumbar spine X-ray shows no abnormalities. Which of the following is the most appropriate next investigation for early diagnosis?

Accepted Answer

MRI sacroiliac joints

Answer

X-ray thoracolumbar spine

Answer

Bone scan

Answer

CT spine

Question 5

A 16-year-old boy presents with jaundice and splenomegaly. His father had a similar illness during adolescence. MCHC : high? What is the most likely diagnosis?

Accepted Answer

B. Hereditary spherocytosis

Answer

D. AIHA

Answer

C. Thalassemia major

Answer

A. IDA

Question 6

A 60-year-old patient presents with pain in multiple bones and a history of increased hat size. On examination, some bones feel warm to touch. Biochemical investigations show normal serum calcium, phosphate, and parathyroid hormone (PTH) levels, but markedly elevated alkaline phosphatase (ALP). What is the most likely diagnosis

Accepted Answer

Paget's disease of bone

Answer

Multiple myeloma

Answer

Osteosarcoma

Answer

Osteomalacia

Question 7

A patient on long-term hydrochlorothiazide therapy presents with features of neuropathy, heart failure, and symmetrical tingling sensations. Which of the following nutrient deficiencies is most likely responsible?

Accepted Answer

Thiamine

Answer

Vitamin B12

Answer

Zinc

Answer

Selenium

Question 8

A patient presents with elevated total cholesterol, subcutaneous xanthomas, and a positive family history of similar findings. Triglyceride levels are normal (<140 mg/dL). What is the most likely type of familial dyslipidemia?

Accepted Answer

Type IIa

Answer

Type I

Answer

Type II

Answer

Type IIb

Question 9

A patient with HIV is newly diagnosed with multidrug-resistant tuberculosis. Which of the following is the appropriate regimen, and what should the patient be monitored for?

Accepted Answer

BPaLM; monitor for immune reconstitution syndrome

Answer

INH + Levofloxacin + Pyrazinamide + ethambutol, monitor for hepatotoxicity

Answer

INH + Levofloxacin + Streptomycin + Ethionamide, monitor for pyridoxine deficiency

Answer

INH + Clarithromycin + Pyrazinamide + Ethambutol, monitor for optic neuritis

Question 10

A patient with HIV develops tuberculosis. When should ART be initiated?

Accepted Answer

Start ATT, then ART after 2 weeks

Answer

Start ART followed by ATT

Answer

ART alone

Answer

Start ART and ATT simultaneously

NEET-PG 2025 — Internal Medicine