NEET-PG 2025 — Internal Medicine
31 Previous Year Questions with Answers & Explanations
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?
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?
A person with jaundice presented with a history of bleeding and symptoms normalised after giving Vitamin K injection. The probable cause is?
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?
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?
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
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?
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?
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?
A patient with HIV develops tuberculosis. When should ART be initiated?
NEET-PG 2025 - Internal Medicine NEET-PG Practice Questions and MCQs
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?
- A. A. Gout
- B. B. Rheumatoid arthritis
- C. C. Pseudogout (Correct Answer)
- D. D. Osteoarthritis
Explanation: ### 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].
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?
- A. Abetalipoproteinemia
- B. Type I hyperlipoproteinemia
- C. Familial hypercholesterolemia
- D. Tangier disease (Correct Answer)
Explanation: ***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.
Question 3: A person with jaundice presented with a history of bleeding and symptoms normalised after giving Vitamin K injection. The probable cause is?
- A. Autoimmune hepatitis
- B. Alpha antitrypsin deficiency
- C. Factor XI deficiency
- D. Biliary obstruction (Correct Answer)
Explanation: ***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.
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?
- A. X-ray thoracolumbar spine
- B. MRI sacroiliac joints (Correct Answer)
- C. Bone scan
- D. CT spine
Explanation: 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].
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?
- A. D. AIHA
- B. B. Hereditary spherocytosis (Correct Answer)
- C. C. Thalassemia major
- D. A. IDA
Explanation: ***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.
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
- A. Multiple myeloma
- B. Osteosarcoma
- C. Osteomalacia
- D. Paget's disease of bone (Correct Answer)
Explanation: ***Paget's disease of bone*** - The presentation with pain in multiple bones, **increased hat size** (due to skull involvement), and markedly elevated **Alkaline Phosphatase (ALP)** with normal calcium and phosphate is the classic biochemical profile [1]. - The sensation of warmth over the bones is caused by increased bone turnover and subsequent **hypervascularity** (increased blood flow) in the affected areas [1]. *Osteosarcoma* - This is a highly malignant bone tumor, typically presenting as localized pain and a mass, especially in the **metaphysis of long bones** (e.g., around the knee). - It does not usually present with the widespread, multiple bone involvement or the classic sign of increased **hat size** seen in this older patient. Paget's disease accounts for most cases of osteosarcoma occurring in older populations [1]. *Multiple myeloma* - This plasma cell malignancy involves the axial skeleton, commonly presenting with **anemia**, **renal failure**, and **hypercalcemia** (due to lytic bone lesions), which is ruled out by the normal calcium level here [2]. - The hallmark is the presence of a serum or urine **M-protein** (paraprotein), and ALP elevation is usually mild or absent unless related to pathological fracture [2]. *Osteomalacia* - This condition is characterized by defective mineralization, leading to low or low-normal serum **calcium** and/or **phosphate** levels, which contradicts the normal biochemical profile presented [3]. - While ALP can be elevated due to secondary hyperparathyroidism or increased osteoblast activity, the findings of severe widespread thickening and increased hat size are not typical [3].
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?
- A. Thiamine (Correct Answer)
- B. Vitamin B12
- C. Zinc
- D. Selenium
Explanation: Thiamine - The combination of **neuropathy** (symmetrical tingling sensations) and **heart failure** (cardiomyopathy) is the classic manifestation of **Beriberi**, caused by Thiamine (Vitamin B1) deficiency [1]. - **Wet Beriberi** causes high-output **cardiac failure**, while **Dry Beriberi** is responsible for **symmetrical peripheral neuropathy** [1]. *Selenium* - Selenium deficiency causes **Keshan disease**, which is characterized by **cardiomyopathy**, but the simultaneous presentation of specific symmetrical peripheral neuropathy is less common. - Deficiency can also lead to muscle pain and weakness, but often does not perfectly match this triad. *Vitamin B12* - Deficiency causes **Subacute Combined Degeneration** (neuropathy and myelopathy) and **megaloblastic anemia**, but severe acute heart failure is not a defining feature. - Neuropathy typically involves a mix of sensory, motor, and central nervous system signs, but the heart failure component is missing. *Zinc* - Zinc deficiency primarily causes **acrodermatitis enteropathica** (dermatitis), impaired wound healing, and immune dysfunction. - It is not a common cause of either **heart failure** or widespread peripheral neuropathy.
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?
- A. Type I
- B. Type IIa (Correct Answer)
- C. Type II
- D. Type IIb
Explanation: ***Type IIa*** - This type, also known as **Familial Hypercholesterolemia**, is characterized by severely elevated **Total (LDL) Cholesterol** and **normal triglyceride** levels (<140 mg/dL) [1]. - The presence of **subcutaneous xanthomas** (often reflecting tendon xanthomas) and a strong family history are classic findings associated with defective **LDL receptors** [1]. *Type I* - This type (Familial Hyperchylomicronemia) is characterized by extremely high **Triglyceride** levels and chylomicrons due to **Lipoprotein Lipase (LPL) deficiency** or C-II deficiency. - The key clinical feature is usually recurrent **pancreatitis** and **eruptive xanthomas**, contrary to the normal TGs seen in this patient. *Type IIb* - This type is defined by elevated levels of both **Total/LDL Cholesterol** and **Triglycerides** (as VLDL) [1]. - An elevated triglyceride level would be mandatory for a Type IIb classification, differentiating it from the patient's normal triglyceride levels. *Type II* - Type II is the broad classification covering all dyslipidemias with elevated **LDL cholesterol** (both IIa and IIb). - For a precise diagnosis in the Fredrickson system, the specific subtype (**IIa** based on normal TGs) is required.
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?
- A. INH + Levofloxacin + Pyrazinamide + ethambutol, monitor for hepatotoxicity
- B. INH + Levofloxacin + Streptomycin + Ethionamide, monitor for pyridoxine deficiency
- C. INH + Clarithromycin + Pyrazinamide + Ethambutol, monitor for optic neuritis
- D. BPaLM; monitor for immune reconstitution syndrome (Correct Answer)
Explanation: ***BPaLM; monitor for immune reconstitution syndrome*** - The **BPaLM** regimen (Bedaquiline, Pretomanid, Linezolid, Moxifloxacin/Levofloxacin) is the recommended all-oral, shorter course (6-9 months) treatment for confirmed drug-resistant or **MDR/RR-TB** (Multidrug/Rifampicin-resistant TB). - HIV co-infected patients are at high risk for **Immune Reconstitution Inflammatory Syndrome (IRIS)**, a paradoxical immune reaction that occurs upon starting effective TB treatment, especially after initiating or optimizing **ART** (Antiretroviral Therapy) [2]. *INH + Levofloxacin + Pyrazinamide + Ethambutol, monitor for hepatotoxicity* - This regimen is inappropriate for **MDR-TB** because it contains **Isoniazid (INH)**, to which the patient's strain is resistant by definition. - While monitoring for **hepatotoxicity** (especially due to Pyrazinamide and INH) is crucial in general TB management, this combination lacks the necessary potent second-line agents. *INH + Levofloxacin + Streptomycin + Ethionamide, monitor for pyridoxine deficiency* - This regimen includes **INH** and older, more toxic second-line drugs like **Streptomycin** (an injectable agent now largely avoided) and **Ethionamide**. - Monitoring for **pyridoxine (Vitamin B6) deficiency** is necessary when using drugs like INH or Ethionamide, but the overall regimen is considered outdated and suboptimal for standard MDR-TB management [1]. *INH + Clarithromycin + Pyrazinamide + Ethambutol, monitor for optic neuritis* - This regimen is incorrect because it contains **INH** (ineffective in MDR-TB) and **Clarithromycin**, which is primarily used for **MAC** (Mycobacterium avium complex) and not a core drug for *M. tuberculosis*. - Although monitoring for **optic neuritis** is specific to **Ethambutol** toxicity, the inclusion of inappropriate drugs makes this an unsuitable MDR-TB treatment combination.
Question 10: A patient with HIV develops tuberculosis. When should ART be initiated?
- A. Start ART followed by ATT
- B. ART alone
- C. Start ART and ATT simultaneously
- D. Start ATT, then ART after 2 weeks (Correct Answer)
Explanation: ***A. Start ATT, then ART after 2 weeks*** - This strategy is the standard recommendation, particularly for patients with CD4 counts >50 cells/mm³, to reduce the risk of **Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome (IRIS)** [1]. - Delaying ART by 2 weeks allows patients to establish tolerance to **Anti-Tubercular Treatment (ATT)** and simplifies the management of potential overlapping drug toxicities [2]. *B. Start ART and ATT simultaneously* - Simultaneous initiation significantly increases the risk and severity of developing **IRIS**, which can worsen the patient's clinical status due to paradoxical worsening of TB symptoms [1]. - This approach also makes it challenging to identify the source of **drug-related toxicities** (e.g., hepatotoxicity), as many ATT and ART drugs are metabolized by the liver [2]. *C. Start ART followed by ATT* - Delaying the initiation of **ATT** is dangerous as active tuberculosis is the immediate life-threatening condition that requires urgent treatment [2]. - Treatment priority in HIV-TB co-infection must first focus on effectively treating the active infection to prevent **disseminated disease** and death. *D. ART alone* - Administering **ART alone** will lead to the progression of active tuberculosis, resulting in significant morbidity and high mortality rates. - ART is necessary but must be combined with effective **ATT** as it is not a treatment for Mycobacterium tuberculosis itself.