An 83-year-old woman with a history of atrial fibrillation, multiple ischemic strokes, and early dementia is found unresponsive in her apartment at her retirement community. She is believed to have not refilled any of her medications for a month, and it is determined that she passed away from a stroke nearly 2 weeks ago. The family is adamant that she receive an autopsy. Which of the following findings are most likely on brain histology?
Q2
A 64-year-old woman is brought to the emergency department 30 minutes after the onset of right-sided weakness and impaired speech. On admission, she is diagnosed with thrombotic stroke and treatment with alteplase is begun. Neurologic examination four weeks later shows residual right hemiparesis. A CT scan of the head shows hypoattenuation in the territory of the left middle cerebral artery. Which of the following processes best explains this finding?
Q3
A 38-year-old man is admitted to the hospital because of fever, yellowing of the skin, and nausea for 1 day. He recently returned from a backpacking trip to Brazil and Paraguay, during which he had a 3-day episode of high fever that resolved spontaneously. Physical examination shows jaundice, epigastric tenderness, and petechiae over his trunk. Five hours after admission, he develops dark brown emesis and anuria. Despite appropriate lifesaving measures, he dies. Postmortem liver biopsy shows eosinophilic degeneration of hepatocytes with condensed nuclear chromatin. This patient’s hepatocytes were most likely undergoing which of the following processes?
Q4
A 22-year-old man presents with an itchy rash. His physical exam reveals crusting vesicular clusters on an erythematous base with surrounding edema, located on his upper back. Which of the following is the most likely diagnosis?
Q5
A 75-year-old woman with a history of stroke 1 year ago was found unconscious on the floor of her home by her son. The patient was brought to the emergency department by ambulance but expired prior to arrival. An autopsy was performed and showed the cause of death to be a massive ischemic stroke. The coroner also examined sections taken from the area of her prior stroke. Which histologic finding would be prominent in the area of her stroke from one year prior?
Cell injury US Medical PG Practice Questions and MCQs
Question 1: An 83-year-old woman with a history of atrial fibrillation, multiple ischemic strokes, and early dementia is found unresponsive in her apartment at her retirement community. She is believed to have not refilled any of her medications for a month, and it is determined that she passed away from a stroke nearly 2 weeks ago. The family is adamant that she receive an autopsy. Which of the following findings are most likely on brain histology?
A. Cellular debris and lymphocytes
B. Cystic cavitation (Correct Answer)
C. Fat saponification
D. Cellular debris and neutrophils
E. Increased binding of acidophilic dyes
Explanation: **Cystic cavitation**
- A **stroke** that occurred two weeks prior would most likely show **cystic cavitation** as the brain tissue attempts to repair itself after the damage.
- Over time, the necrotic tissue is removed, and a fluid-filled cavity forms, which is the final stage of **infarction resolution**.
*Cellular debris and lymphocytes*
- While **cellular debris** would be present, **lymphocytes** are typically later responders in inflammation, and at two weeks, the most prominent feature would be cavitation.
- **Microglia** and **macrophages** would be the primary cells involved in clearing debris, leading to cavitation.
*Fat saponification*
- **Fat saponification** is a type of **fat necrosis** seen in areas like the pancreas or breast, not typically in the brain after an ischemic stroke.
- This process involves the hydrolysis of triglycerides into fatty acids that combine with calcium, forming a chalky substance.
*Cellular debris and neutrophils*
- **Neutrophils** are characteristic of the very **early stages of acute inflammation**, typically within the first 24-48 hours after an ischemic stroke.
- By two weeks, most neutrophils would have resolved, and mononuclear cells and macrophages would predominate.
*Increased binding of acidophilic dyes*
- **Increased binding of acidophilic dyes** (like eosin) is seen in **early ischemic changes** (e.g., within hours to days), indicating **cell necrosis** like **red neurons**.
- At two weeks, the tissue has progressed beyond this immediate necrotic stage to active removal and cavitation.
Question 2: A 64-year-old woman is brought to the emergency department 30 minutes after the onset of right-sided weakness and impaired speech. On admission, she is diagnosed with thrombotic stroke and treatment with alteplase is begun. Neurologic examination four weeks later shows residual right hemiparesis. A CT scan of the head shows hypoattenuation in the territory of the left middle cerebral artery. Which of the following processes best explains this finding?
A. Liquefactive necrosis (Correct Answer)
B. Caseous necrosis
C. Gangrenous necrosis
D. Coagulative necrosis
E. Fat necrosis
Explanation: ***Liquefactive necrosis***
- This is the characteristic type of necrosis seen in the **central nervous system** following an ischemic insult like a stroke.
- The brain tissue is rapidly digested by hydrolytic enzymes, forming a **cyst-like cavity** filled with fluid (hence "hypoattenuation" on CT), reflecting the accumulation of necrotic cellular debris.
*Caseous necrosis*
- This is a form of cell death typically associated with **tuberculous infections** and some fungal infections.
- It results in the formation of a cheesy, friable material consisting of fragmented cells and granular debris, which is not characteristic of stroke.
*Gangrenous necrosis*
- This type of necrosis is typically seen in the **extremities** and is often associated with a loss of blood supply and subsequent bacterial infection.
- It involves tissue death due to ischemia, often accompanied by signs of putrefaction, making it distinct from a brain infarct.
*Coagulative necrosis*
- This is the most common type of necrosis and occurs in solid organs (e.g., heart, kidney) due to **ischemia**, preserving the architectural outlines of the dead cells for a period.
- Unlike the brain, where rapid liquefaction occurs, coagulative necrosis is not the primary form of cell death observed in the central nervous system after an ischemic stroke.
*Fat necrosis*
- This occurs in **adipose tissue**, usually due to trauma or enzymatic digestion (e.g., in pancreatitis).
- It involves the breakdown of fats into fatty acids, which then combine with calcium to form chalky white areas, which is not relevant to a cerebral infarct.
Question 3: A 38-year-old man is admitted to the hospital because of fever, yellowing of the skin, and nausea for 1 day. He recently returned from a backpacking trip to Brazil and Paraguay, during which he had a 3-day episode of high fever that resolved spontaneously. Physical examination shows jaundice, epigastric tenderness, and petechiae over his trunk. Five hours after admission, he develops dark brown emesis and anuria. Despite appropriate lifesaving measures, he dies. Postmortem liver biopsy shows eosinophilic degeneration of hepatocytes with condensed nuclear chromatin. This patient’s hepatocytes were most likely undergoing which of the following processes?
A. Regeneration
B. Steatosis
C. Necrosis
D. Apoptosis (Correct Answer)
E. Proliferation
Explanation: ***Apoptosis***
- The patient's symptoms (fever, jaundice, epigastric tenderness, petechiae, dark emesis, anuria) and history of travel to endemic areas are highly suggestive of **Yellow Fever**.
- **Eosinophilic degeneration of hepatocytes with condensed nuclear chromatin**, described as **Councilman bodies** or **apoptotic bodies**, is a characteristic histological finding in Yellow Fever and indicates programmed cell death.
*Regeneration*
- This process involves the replacement of damaged tissue with new, healthy tissue, which would contradict the patient's rapidly deteriorating condition and death.
- While regeneration can occur in the liver, the described histological findings of **eosinophilic degeneration** and **condensed nuclear chromatin** are indicative of cell death, not repair.
*Steatosis*
- **Steatosis** refers to the accumulation of fat droplets within hepatocytes, which is usually seen in conditions like alcoholic liver disease or non-alcoholic fatty liver disease.
- This is not consistent with the eosinophilic degeneration and condensed chromatin described, which point to a different type of cellular injury.
*Necrosis*
- **Necrosis** is a form of unregulated cell death often associated with inflammation and cellular swelling; the description of **eosinophilic degeneration** and **condensed nuclear chromatin** points specifically to apoptotic cell death rather than necrotic changes which would typically include cell swelling and rupture.
- While Yellow Fever does cause significant liver damage leading to cell death, the specific histological features (e.g., Councilman bodies) are characteristic of **apoptosis**, not typically seen in necrosis.
*Proliferation*
- **Proliferation** refers to an increase in the number of cells, typically in response to a stimulus or as part of a disease process like cancer.
- The patient's rapid decline and the histological findings of dying cells (eosinophilic degeneration, condensed chromatin) are antithetical to cellular proliferation.
Question 4: A 22-year-old man presents with an itchy rash. His physical exam reveals crusting vesicular clusters on an erythematous base with surrounding edema, located on his upper back. Which of the following is the most likely diagnosis?
A. Herpes simplex virus infection
B. Impetigo
C. Atopic eczema
D. Herpes zoster (Correct Answer)
E. Contact dermatitis
Explanation: ***Herpes zoster***
- The description of **crusting vesicular clusters on an erythematous base with surrounding edema** is highly characteristic of **herpes zoster** (shingles).
- While not explicitly mentioned, herpes zoster typically follows a **dermatomal distribution**, which would explain a localized rash on the upper back.
*Herpes simplex virus infection*
- HSV lesions are also vesicular but usually present as **grouped vesicles on an erythematous base**, often around the mouth (cold sores) or genitals.
- Unlike zoster, HSV **causes** recurrent infections at the same site, and widespread lesions are rare in immunocompetent individuals.
*Impetigo*
- Impetigo is a superficial bacterial infection characterized by **honey-colored crusts** that develop from ruptured vesicles or bullae.
- While it can be vesicular, the primary lesions are typically **pustules** or vesicles that rapidly become crusted, and the characteristic honey-colored crust is a key differentiating feature.
*Atopic eczema*
- Atopic eczema presents with **erythematous, intensely pruritic patches and plaques**, often with lichenification in chronic cases.
- While vesicles can occur during acute flares, the predominant features are usually dry, scaly skin and intense itching, without the prominent clustering of vesicles seen in the patient.
*Contact dermatitis*
- Contact dermatitis manifests as an **itchy, erythematous rash** that appears at the site of contact with an allergen or irritant.
- It can include vesicles, but the rash typically has clear borders reflecting the area of contact and often does not show the highly grouped, clustered pattern characteristic of shingles.
Question 5: A 75-year-old woman with a history of stroke 1 year ago was found unconscious on the floor of her home by her son. The patient was brought to the emergency department by ambulance but expired prior to arrival. An autopsy was performed and showed the cause of death to be a massive ischemic stroke. The coroner also examined sections taken from the area of her prior stroke. Which histologic finding would be prominent in the area of her stroke from one year prior?
A. Necrosis and neutrophils
B. Red neurons
C. Macrophages
D. Cyst formed by astrocyte processes (Correct Answer)
E. Reactive gliosis and vascular proliferation
Explanation: ***Cyst formed by astrocyte processes***
- After a significant ischemic stroke, the brain tissue undergoes liquefactive necrosis. Over time (months to a year), the necrotic tissue is removed by macrophages, leaving behind a fluid-filled cavity or **cyst**.
- This cyst is typically surrounded by a wall of **reactive astrocytes** (gliosis) which form a glial scar to contain the damage.
*Necrosis and neutrophils*
- **Necrosis** is characteristic of acute ischemic injury, but neutrophils are prominent only in the very early stages (hours to days) of inflammation.
- One year after a stroke, neutrophils would no longer be present; the area would have progressed beyond acute inflammation.
*Red neurons*
- **Red neurons** are an early histological sign of irreversible neuronal damage due to ischemia, appearing within **12-24 hours** after the insult.
- They represent acute cell death but would have long been cleared by a year post-stroke.
*Macrophages*
- **Macrophages** (microglia) are actively involved in clearing necrotic debris from the stroke site, primarily within **days to weeks** after the event.
- While still present, they are less prominent than the established cyst and glial scar at **one year**.
*Reactive gliosis and vascular proliferation*
- **Reactive gliosis** (astrocytic activation) is indeed a component of the long-term response to injury, contributing to the formation of the cyst wall.
- However, **vascular proliferation** is more characteristic of subacute infarcts (weeks) and less dominant than the mature cystic lesion at one year.
