INI-CET 2024 Practice Questions

Q: Identify the type of joint in the image provided.

Synovial joint. ***Synovial joint*** - The image depicts a **costovertebral joint**, which connects a rib to a thoracic vertebra. These joints are **diarthrotic**, meaning they are freely movable, characteristic of synovial joints. - Synovial joints are characterized by the presence of a **synovial cavity**, articular cartilage, an articular capsule, and synovial fluid, allowing for a wide range of motion. *Syndesmosis* - A syndesmosis is a type of **fibrous joint** where two bones are joined by a ligament or a membrane, allowing for very limited movement, such as the distal tibiofibular joint. - This definition does not match the image, which shows a joint designed for movement between the rib and vertebra. *Synarthrosis* - Synarthrosis is a classification for **immovable joints**, such as sutures in the skull. - The costovertebral joints, as shown, allow for movement during respiration and are therefore not synarthrotic. *Symphysis* - A symphysis is a type of **cartilaginous joint** where bones are joined by **fibrocartilage**, allowing for slight movement. Examples include the pubic symphysis or intervertebral discs. - The costovertebral joint shown in the image is a synovial articulation, not a cartilaginous joint.

Q: Identify the marked structure in the image.

Cerebellum. ***Cerebellum*** - The image points to the distinct, posterior inferior structure of the brain, characterized by its **folia** and arbour-vitae-like internal structure, which is the cerebellum. - The cerebellum is primarily involved in **motor control**, including coordination, precision, and accurate timing. *Cerebrum* - The cerebrum is the **largest part of the brain**, located superiorly, responsible for higher functions like thought, voluntary movement, and sensory processing. - It consists of two hemispheres connected by the corpus callosum and is characterized by its **gyri** and **sulci**. *Brain stem* - The brain stem is located inferior to the cerebrum and anterior to the cerebellum, connecting the cerebrum and cerebellum to the **spinal cord**. - It controls vital functions such as **breathing**, heart rate, and sleep, and is composed of the midbrain, pons, and medulla oblongata. *Corpus callosum* - The corpus callosum is a large, C-shaped nerve fiber bundle located deep within the brain, under the cerebral cortex. - Its primary function is to **connect the two cerebral hemispheres**, facilitating communication between them.

Q: Identify the type of skin lesion shown in the image.

Macule. ***Macule*** - The lesion shown is a **macule**, characterized by being **flat and circumscribed** with no elevation above the skin surface. - A macule is defined as a **skin discoloration less than 1 cm in diameter** without any palpable change in texture or thickness. - Classic examples include **freckles, flat nevi, and café-au-lait spots**. - The image demonstrates the typical appearance with clear borders and no vertical component. *Papule* - A papule is an **elevated, solid lesion less than 1 cm** in diameter. - Unlike the lesion shown, papules have a **palpable raised component** above the skin surface. - Examples include acne, warts, and lichen planus. *Patch* - A patch is similar to a macule but is **larger than 1 cm in diameter**. - While also flat, the size criterion differentiates it from a macule. - Examples include vitiligo patches and large birthmarks. *Nodule* - A nodule is a **solid, elevated lesion greater than 1 cm** that extends into deeper skin layers. - It has both elevation and depth, unlike the flat lesion shown. - Examples include dermatofibromas, lipomas, and some cysts.

Q: An 11-year-old boy presented with a cough for 15 days. On examination, he was found to have cervical lymphadenopathy. Lymph node biopsy showed the following findings. What could be the diagnosis?

Tuberculosis. ***Tuberculosis*** - The image likely displays **granulomatous inflammation** with **caseous necrosis**, which is highly characteristic of **tuberculosis**, especially in someone presenting with a persistent cough and lymphadenopathy. - The presence of **cervical lymphadenopathy** along with a **cough** for 15 days in an 11-year-old boy points towards extrapulmonary tuberculosis or primary tuberculosis infection affecting the mediastinal lymph nodes with cervical involvement. *Leprosy* - While leprosy also causes granulomas, it typically manifests as skin lesions and nerve involvement, and lymphadenopathy is less common or specific as the primary initial presentation. - The granulomas in leprosy are often **epithelioid** with **foamy histiocytes** and numerous acid-fast bacilli, which are not explicitly described or obvious in the provided context for a definitive diagnosis without special stains. *Sarcoidosis* - Sarcoidosis involves **non-caseating granulomas**, meaning there is no central necrosis, which is a key differentiating feature from the caseating necrosis often seen in tuberculosis. - Although sarcoidosis can cause lymphadenopathy and cough, the microscopic features in the image, particularly if showing necrosis, would argue against sarcoidosis. *Syphilis* - Syphilis can cause lymphadenopathy (especially in secondary syphilis), but the characteristic histological finding is usually a **plasma cell-rich infiltrate** with **endarteritis obliterans**, not typically prominent granulomas with caseous necrosis. - Clinical presentation with cough and chronic lymphadenopathy in an 11-year-old would also make syphilis a less likely primary consideration without other suggestive signs.

Q: Which of the following is a known risk factor for cholangiocarcinoma?

Clonorchis sinensis infestation. ***Clonorchis sinensis infestation*** - **Clonorchis sinensis**, also known as the Chinese liver fluke, is a well-established and significant risk factor for the development of **cholangiocarcinoma**. - Chronic inflammation and irritation of the bile ducts caused by the parasite are believed to promote malignant transformation. *Giardia lamblia (intestinal protozoa) infection* - **Giardia lamblia** is a common intestinal parasite causing giardiasis, characterized by diarrhea and malabsorption. - While it affects the gastrointestinal tract, there is **no known association** between *Giardia* infection and an increased risk of cholangiocarcinoma. *Paragonimus westermani infestation* - **Paragonimus westermani** is a lung fluke that primarily causes paragonimiasis, affecting the lungs and leading to cough and hemoptysis. - This parasite is not associated with direct bile duct inflammation or an increased risk of **cholangiocarcinoma**. *Ascaris lumbricoides (roundworm) infection* - **Ascaris lumbricoides** is a large intestinal roundworm that can cause intestinal obstruction or nutrient deficiencies. - Although it can occasionally migrate into the biliary tree, it is **not considered a risk factor** for cholangiocarcinoma [1].

Q: A 6-year-old boy presents with fever and chills, cough, rapid breathing, difficulty breathing, and chest pain. A culture from a respiratory sample shows Gram-positive bacteria. What is the most likely organism causing this infection?

Streptococcus pneumoniae. ***Streptococcus pneumoniae*** - This clinical picture describes typical symptoms of **pneumonia** in a child, including fever, cough, rapid and difficult breathing, and chest pain. - **_Streptococcus pneumoniae_** is the most common bacterial cause of community-acquired pneumonia in children. The respiratory sample showing gram-positive bacteria further supports this. *Staphylococcus aureus* - While **_Staphylococcus aureus_** can cause pneumonia, it is less common than _Streptococcus pneumoniae_ in community-acquired cases in healthy children and often associated with more severe, necrotizing forms or post-viral infections. - While it is a **Gram-positive bacterium**, its clinical presentation would not be the most likely first choice for typical pneumonia symptoms in this age group. *Propionibacterium acnes* - **_Propionibacterium acnes_** (now *Cutibacterium acnes*) is primarily associated with **acne vulgaris** and, less commonly, opportunistic infections related to implanted devices or some rare soft tissue infections. - It is not a typical cause of primary respiratory infections like pneumonia. *Streptococcus pyogenes* - **_Streptococcus pyogenes_** (Group A Streptococcus) is known for causing **pharyngitis** (strep throat), skin infections (impetigo, cellulitis), and scarlet fever. - While it can rarely cause pneumonia, it is not a common cause, and the constellation of symptoms points more strongly to _Streptococcus pneumoniae_.

Q: HBsAg is based on which principle

ELISA. ***ELISA*** - **Enzyme-linked immunosorbent assay (ELISA)** is a widely used laboratory test to detect and quantify antigens (like HBsAg) or antibodies in a sample. - It involves an enzyme-linked antibody that reacts with a substrate to produce a detectable signal, making it highly sensitive and specific for **HBsAg detection**. *Immunochromatography assays* - These are typically **rapid diagnostic tests (RDTs)** that provide quick qualitative results, often used for point-of-care testing. - While they can detect HBsAg, they generally have lower sensitivity and specificity compared to ELISA. *Chemiluminescence* - This is a detection method used in some immunoassays where a chemical reaction emits light, often providing higher sensitivity than colorimetric detection. - While it can be incorporated into HBsAg testing platforms, it is a *detection principle* rather than the primary assay principle like ELISA itself. *Immunofluorescence* - This technique uses **fluorescently labeled antibodies** to visualize antigens in cells or tissues under a fluorescence microscope [1]. - It is used for localization and identification of antigens, but not typically the primary method for routine quantitative HBsAg serology [1]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 259-260.

Q: In which type of lung carcinoma is the p53 mutation most commonly observed?

Squamous cell carcinoma (SCC). ***Small cell carcinoma*** - **Small cell lung carcinoma (SCLC)** has the highest frequency of **p53 mutations**, occurring in approximately **90-95%** of cases. - These mutations are associated with the **aggressive nature** and **poor prognosis** of SCLC, contributing to its rapid growth and early metastasis. *Adenocarcinoma* - **Adenocarcinoma** has p53 mutations in approximately **50-60%** of cases, which is less frequent than SCLC. - This subtype is more commonly associated with **EGFR mutations** and **ALK rearrangements**, particularly in non-smokers. *Squamous cell carcinoma (SCC)* - **Squamous cell carcinoma** shows p53 mutations in about **70-80%** of cases, but still lower than SCLC. - It is more strongly associated with **smoking** and often displays mutations in **CDKN2A** and **PIK3CA** pathways. *Large cell carcinoma* - **Large cell carcinoma** has variable p53 mutation rates, typically **40-60%** of cases. - This subtype is less well-characterized molecularly and represents a **diagnosis of exclusion** among lung cancers.

Q: Identify the condition in the image below?

Lacunar infarct. ***Lacunar infarct*** - The image displays a small, well-demarcated **hypodensity** (darker area) in the basal ganglia region, characteristic of a lacunar infarct. - Lacunar infarcts are typically caused by **occlusion of small perforating arteries** and result in small, deep infarcts, often appearing as precise, round or ovoid lesions on CT. *Embolic infarct* - Embolic infarcts tend to be **larger**, wedge-shaped, and often extend to the cortical surface, unlike the deep, small lesion seen. - They are commonly associated with a **cardiac source** or large artery atherosclerosis leading to distal embolization. *Thrombotic infarct* - Thrombotic infarcts are usually **larger** areas of infarction due to occlusion of a major artery, often preceded by symptoms like TIAs. - While they also appear hypodense, they are typically **more extensive** and less precisely defined than a lacunar infarct in the early stages. *Intracerebral hemorrhage* - Intracerebral hemorrhage would appear as a **hyperdense** (bright white) area on a non-contrast CT scan due to the presence of acute blood. - The image clearly shows a **hypodense lesion**, ruling out acute hemorrhage.

Question 1

Identify the type of joint in the image provided.

Accepted Answer

Synovial joint

Answer

Syndesmosis

Answer

Synarthrosis

Answer

Symphysis

Question 2

Identify the marked structure in the image.

Accepted Answer

Cerebellum

Answer

Cerebrum

Answer

Brain stem

Answer

Corpus callosum

Question 3

Identify the type of skin lesion shown in the image.

Accepted Answer

Macule

Answer

Papule

Answer

Patch

Answer

Nodule

Question 4

An 11-year-old boy presented with a cough for 15 days. On examination, he was found to have cervical lymphadenopathy. Lymph node biopsy showed the following findings. What could be the diagnosis?

Accepted Answer

Tuberculosis

Answer

Leprosy

Answer

Sarcoidosis

Answer

Syphilis

Question 5

Which of the following is a known risk factor for cholangiocarcinoma?

Accepted Answer

Clonorchis sinensis infestation

Answer

Giardia lamblia (intestinal protozoa) infection

Answer

Ascaris lumbricoides (roundworm) infection

Answer

Paragonimus westermani infestation

Question 6

A 6-year-old boy presents with fever and chills, cough, rapid breathing, difficulty breathing, and chest pain. A culture from a respiratory sample shows Gram-positive bacteria. What is the most likely organism causing this infection?

Accepted Answer

Streptococcus pneumoniae

Answer

Streptococcus pyogenes

Answer

Staphylococcus aureus

Answer

Propionibacterium acnes

Question 7

HBsAg is based on which principle

Accepted Answer

ELISA

Answer

Chemiluminescence

Answer

Immunofluorescence

Answer

Immunochromatography assays

Question 8

In which type of lung carcinoma is the p53 mutation most commonly observed?

Accepted Answer

Squamous cell carcinoma (SCC)

Answer

Adenocarcinoma

Answer

Large cell carcinoma

Answer

Small cell carcinoma

Question 9

Identify the condition in the image below?

Accepted Answer

Lacunar infarct

Answer

Embolic infarct

Answer

Thrombotic infarct

Answer

Intracerebral hemorrhage

Question 10

A 40-year-old male with a head injury presents with a GCS of 8, BP of 90/60, and HR of 120. A CT scan shows an epidural hematoma. What are the immediate management priorities?

Accepted Answer

Intubation and ventilation

Answer

Administer mannitol for intracranial pressure management

Answer

Perform immediate craniotomy

Answer

Administer intravenous fluids and monitor vital signs

INI-CET 2024

Anatomy

Dermatology

Internal Medicine

Microbiology

Pathology

Radiology

Surgery