Orthopaedics
1 questionsA 40-year old man presented with acute onset pain and swelling of the left great toe. On X-ray, a punched-out lytic lesion is seen on the phalanx with sclerotic margins and overhanging bony edges. What is the most likely diagnosis?
INI-CET 2014 - Orthopaedics INI-CET Practice Questions and MCQs
Question 11: A 40-year old man presented with acute onset pain and swelling of the left great toe. On X-ray, a punched-out lytic lesion is seen on the phalanx with sclerotic margins and overhanging bony edges. What is the most likely diagnosis?
- A. Gout (Correct Answer)
- B. Rheumatoid arthritis
- C. Psoriatic arthritis
- D. Reiter's syndrome
Explanation: ### Explanation The clinical presentation and radiographic findings are classic for **Gouty Arthritis**. **1. Why Gout is Correct:** The patient presents with **Podagra** (acute involvement of the first metatarsophalangeal joint), which is the most common site for gout. The X-ray description is pathognomonic: * **Punched-out lytic lesions:** These represent intraosseous tophi (monosodium urate crystals). * **Martel’s Sign (Overhanging edges):** The sclerotic, "rat-bite" erosions with overhanging bony margins are highly characteristic of chronic tophaceous gout. Unlike other inflammatory arthritides, the joint space in gout is often preserved until late stages. **2. Why Other Options are Incorrect:** * **Rheumatoid Arthritis (RA):** Typically presents with symmetrical involvement of small joints (MCP, PIP). Radiologically, it shows **periarticular osteopenia** and marginal erosions without sclerotic borders or overhanging edges. * **Psoriatic Arthritis:** While it can affect the distal phalanges, it is characterized by the "pencil-in-cup" deformity and periosteal new bone formation, not isolated punched-out lesions with sclerotic margins. * **Reiter’s Syndrome (Reactive Arthritis):** Usually follows a GI or GU infection and presents as an asymmetric oligoarthritis, often involving the heel (Achilles tendonitis) or sacroiliac joints. **3. High-Yield Pearls for NEET-PG:** * **Gold Standard Diagnosis:** Polarized light microscopy showing **needle-shaped, negatively birefringent** crystals (Yellow when parallel to the axis). * **Martel’s Sign:** The radiographic hallmark of gout (overhanging edges). * **Drug of Choice:** NSAIDs are first-line for acute attacks; **Colchicine** is an alternative. **Allopurinol** (Xanthine oxidase inhibitor) is used for chronic management but should *never* be started during an acute attack. * **Dietary triggers:** High purine foods (red meat, seafood) and alcohol.
Pathology
1 questionsA 6-year-old Afroamerican boy presented with abdominal pain, chronic hemolysis, and abnormal RBC shape on peripheral smear. What is the most likely underlying molecular disorder responsible for this condition?
INI-CET 2014 - Pathology INI-CET Practice Questions and MCQs
Question 11: A 6-year-old Afroamerican boy presented with abdominal pain, chronic hemolysis, and abnormal RBC shape on peripheral smear. What is the most likely underlying molecular disorder responsible for this condition?
- A. Point mutation (Correct Answer)
- B. Trinucleotide repeat
- C. Antibody against RBC membrane
- D. Genomic imprinting
Explanation: ### Explanation The clinical presentation of a young African American child with **chronic hemolysis**, **abdominal pain** (likely due to vaso-occlusive crises or splenic sequestration), and **abnormal RBC morphology** (sickle cells) is diagnostic of **Sickle Cell Anemia (SCA)** [1], [2]. **1. Why "Point Mutation" is Correct:** Sickle Cell Anemia is caused by a specific **missense point mutation** in the $\beta$-globin gene located on chromosome 11. Specifically, there is a substitution of **Adenine by Thymine (GAG $\rightarrow$ GTG)**. This results in the replacement of the amino acid **Glutamic acid** (polar/hydrophilic) with **Valine** (non-polar/hydrophobic) at the **6th position** of the $\beta$-globin chain [1]. This single amino acid change causes Hemoglobin S (HbS) to polymerize under deoxygenated conditions, leading to the characteristic "sickling" of erythrocytes [2]. **2. Why Incorrect Options are Wrong:** * **Trinucleotide repeat:** This is the mechanism for "Anticipation" seen in neurological disorders like Huntington’s disease or Fragile X syndrome, not hemoglobinopathies. * **Antibody against RBC membrane:** This describes **Autoimmune Hemolytic Anemia (AIHA)** [2]. While it causes hemolysis, it is an acquired immune-mediated process, not a molecular genetic disorder, and typically presents with spherocytes. * **Genomic imprinting:** This involves epigenetic silencing of genes (e.g., Prader-Willi or Angelman syndromes) and does not play a role in the inheritance of structural hemoglobin variants. **High-Yield Clinical Pearls for NEET-PG:** * **Inheritance:** Autosomal Recessive [2]. * **Protective Effect:** Heterozygotes (Sickle cell trait) are protected against *Plasmodium falciparum* malaria. * **Diagnosis:** **Hb Electrophoresis** is the gold standard (HbS moves slower than HbA toward the anode). * **Complications:** Autosplenectomy (by age 6-8), Howell-Jolly bodies on smear, and increased risk of *Salmonella* osteomyelitis [3]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 598-599. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 652-654. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 645-646.
Surgery
1 questionsA 17-year-old female underwent Fine Needle Aspiration cytology (FNAC) for a lump in the breast which was non-tender, firm and mobile. Which of the following features would suggest a benign breast disease?
INI-CET 2014 - Surgery INI-CET Practice Questions and MCQs
Question 11: A 17-year-old female underwent Fine Needle Aspiration cytology (FNAC) for a lump in the breast which was non-tender, firm and mobile. Which of the following features would suggest a benign breast disease?
- A. Dyscohesive ductal epithelial cells without cellular fragments
- B. Tightly arranged ductal epithelial cells with dyscohesive bare nuclei (Correct Answer)
- C. Stromal predominance with spindle cells
- D. Polymorphism with single or arranged ductal epithelial cells
Explanation: ### **Explanation** The clinical presentation of a 17-year-old female with a firm, non-tender, and highly mobile breast lump (the "breast mouse") is classic for a **Fibroadenoma**, the most common benign breast tumor in young women. **Why Option B is Correct:** The cytological hallmark of benign breast lesions, particularly fibroadenomas, is the presence of **bipolar bare nuclei** (also called "naked nuclei") scattered in the background. These represent myoepithelial cells that have been stripped of their cytoplasm. Their presence is a strong indicator of benignity. Additionally, benign lesions show **tightly cohesive clusters** of ductal epithelial cells, often arranged in "antler-like" or "staghorn" patterns. **Analysis of Incorrect Options:** * **Option A:** **Dyscohesive** ductal cells (cells falling apart) are a hallmark of **malignancy** (e.g., Ductal Carcinoma). In cancer, cells lose their adhesion molecules (like E-cadherin), leading to a scattered, non-cohesive appearance. * **Option C:** While fibroadenomas have a stromal component, "stromal predominance with spindle cells" is more characteristic of a **Phyllodes tumor**, which requires differentiation from a simple fibroadenoma due to its potential for rapid growth and recurrence. * **Option D:** **Polymorphism** (variation in size and shape) and single epithelial cells are features of **cellular atypia and malignancy**. Benign cells are typically monomorphic (uniform). ### **High-Yield Clinical Pearls for NEET-PG** * **Triple Assessment:** Clinical examination + Imaging (Ultrasound for <30y, Mammography for >30y) + Pathology (FNAC/Core Biopsy). * **FNAC vs. Core Biopsy:** FNAC is excellent for identifying bare nuclei (benignity), but Core Biopsy is preferred if malignancy is suspected to assess invasiveness and receptor status (ER/PR/Her2neu). * **The "Breast Mouse":** A term used for Fibroadenoma due to its extreme mobility within the breast tissue. * **Cytology Rule:** The presence of **myoepithelial cells** (bare nuclei) virtually excludes a diagnosis of invasive breast cancer.