Effusion Cytology — MCQs
Best marker for distinguishing reactive from neoplastic mesothelial proliferation?
A patient's skin biopsy shows a box-shaped or square-shaped pattern of inflammatory infiltrate, as shown in the image. What is the most likely diagnosis?
A CT scan shows the 'crazy paving' pattern in both lungs. Which bronchoalveolar lavage finding would confirm pulmonary alveolar proteinosis?
All the following in the Light's criteria are suggestive of exudative pleural effusion except.
Which of the following is a primary pleural tumor?
Which histological type of lung cancer is most commonly associated with metastasis?
A 10yr old boy with a known case of nephrotic syndrome since 4 years on treatment brought to the pediatric OPD with chief complaint of difficulty in breathing. There is no history of fever. On examination, respiratory system was normal except slightly reduced breath sounds on right infra-axillary region. Paediatrician thinks of pleural effusion. What is next best modality of investigation to detect pleural effusion?
Which of the following has the minimal chance of causing mesothelioma?
TTF-1 (Thyroid Transcription Factor-1) immunohistochemical marker is most commonly seen in which of the following?
In a patient with breast cancer, the following are poor prognostic factors except
Effusion Cytology Indian Medical PG Practice Questions and MCQs
Question 1: Best marker for distinguishing reactive from neoplastic mesothelial proliferation?
- A. Calretinin
- B. WT1
- C. D2-40
- D. BAP1 loss (Correct Answer)
Explanation: ***BAP1 loss*** - Biallelic **BAP1 inactivation**, detected as a loss of nuclear BAP1 immunoreactivity, is a highly specific marker for distinguishing **malignant mesothelioma** from benign reactive mesothelial proliferations. - While other markers confirm mesothelial lineage, only **BAP1 loss** directly points towards malignancy in this context. *Calretinin* - **Calretinin** is a sensitive marker for **mesothelial differentiation**, meaning it is expressed in both reactive and neoplastic mesothelial cells. - Therefore, it cannot differentiate between **benign reactive mesothelium** and **malignant mesothelioma**. *WT1* - **WT1 (Wilms Tumor 1)** is another valuable marker for **mesothelial lineage**, showing nuclear staining in both reactive and neoplastic mesothelial cells. - Like calretinin, its presence indicates mesothelial origin but does not distinguish between **benign and malignant processes**. *D2-40* - **D2-40 (podoplanin)** is a cell surface glycoprotein that is reliably expressed by normal and neoplastic mesothelial cells. - It is used to confirm the **mesothelial nature** of a proliferation but is not specific for malignancy.
Question 2: A patient's skin biopsy shows a box-shaped or square-shaped pattern of inflammatory infiltrate, as shown in the image. What is the most likely diagnosis?
- A. Lichen planus (Correct Answer)
- B. Lichen amyloidosis
- C. Morphea
- D. Lichen nitidus
Explanation: ***Lichen planus*** - The image shows a characteristic **"box-shaped" or "square-shaped" infiltrate** of lymphocytes at the dermal-epidermal junction, obscuring the basal layer. - Other features consistent with lichen planus include **hypergranulosis**, **sawtooth rete ridges**, and **Civatte bodies** (apoptotic keratinocytes) in the basal layer. *Lichen amyloidosis* - This condition is characterized by deposition of **amyloid material** in the papillary dermis, often associated with keratinocyte necrosis. - While it can present with pruritic papules similar to lichen planus, the histology specifically shows **amyloid deposits**, not the typical basal cell damage or band-like infiltrate seen in the image. *Morphea* - Morphea is a form of localized scleroderma, characterized by **thickening of collagen bundles** in the dermis and subcutaneous tissue, leading to hardened skin plaques. - Histologically, it involves **sclerosis** and homogenization of collagen, with a sparse inflammatory infiltrate, which is distinct from the dense band-like infiltrate and epidermal changes shown. *Lichen nitidus* - Lichen nitidus is characterized by **small, discrete granulomas** within the papillary dermis (the "ball-and-claw" appearance), with epithelial extensions embracing the inflammatory infiltrate. - It involves a more **localized inflammatory process** and distinct granulomatous appearance, rather than the broad, band-like infiltrate seen across the dermal-epidermal junction in this image.
Question 3: A CT scan shows the 'crazy paving' pattern in both lungs. Which bronchoalveolar lavage finding would confirm pulmonary alveolar proteinosis?
- A. Milky fluid with PAS-positive material (Correct Answer)
- B. Hemosiderin-laden macrophages
- C. Eosinophilia >25%
- D. CD4/CD8 ratio >3.5
Explanation: ***Milky fluid with PAS-positive material*** - A **milky, turbid bronchoalveolar lavage (BAL) fluid** is characteristic of **pulmonary alveolar proteinosis (PAP)** due to the accumulation of lipoproteinaceous material [1]. - **Periodic Acid-Schiff (PAS) staining** confirms the presence of this **glycoprotein-rich surfactant material**, which reacts positively [1]. *Hemosiderin-laden macrophages* - These are indicative of **pulmonary hemorrhage**, not PAP. - They are commonly seen in conditions like **Goodpasture syndrome** or **idiopathic pulmonary hemosiderosis**. *Eosinophilia >25%* - Significant **eosinophilia in BAL fluid** is a hallmark of **eosinophilic pneumonia**, a different interstitial lung disease. - It suggests an **allergic or hypersensitivity reaction** in the lungs. *CD4/CD8 ratio >3.5* - An **elevated CD4/CD8 ratio** in BAL fluid is highly suggestive of **sarcoidosis**, a granulomatous inflammatory disease. - This ratio reflects the **lymphocyte population** in the alveoli, not lipoproteinaceous accumulation. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 703-705.
Question 4: All the following in the Light's criteria are suggestive of exudative pleural effusion except.
- A. Pleural fluid LDH : serum LDH ratio > 0.6
- B. Pleural fluid ADA < 16 (Correct Answer)
- C. Pleural fluid protein : serum protein ratio > 0.5
- D. Pleural fluid LDH > two-thirds of the upper limit of serum LDH
Explanation: ***Pleural fluid ADA < 16*** - **Adenosine deaminase (ADA)** levels are used to diagnose **tuberculous pleural effusions**, with high levels (>40 U/L) suggesting exudate. [1] - A pleural fluid ADA of < 16 U/L is indicative of a **transudative effusion**, as it rules out tuberculosis. [1] *Pleural fluid LDH : serum LDH ratio > 0.6* - This criterion, where the ratio of **pleural fluid LDH** to **serum LDH** is greater than 0.6, is one of the classic **Light's criteria** for identifying an exudative effusion. [1] - An exudate typically has higher protein and enzyme content due to increased capillary permeability or local production. [1] *Pleural fluid protein : serum protein ratio > 0.5* - This indicates that the **protein concentration** in the pleural fluid is significantly higher than in the serum. [1] - This ratio is a key component of **Light's criteria** and suggests an inflammatory or exudative process. [1] *Pleural fluid LDH > two-thirds of the upper limit of serum LDH* - This is another major criterion in **Light's criteria** for defining an exudative pleural effusion. [1] - An elevated **pleural fluid LDH** suggests increased cellular activity or cell breakdown within the pleural space, characteristic of an exudate. [1]
Question 5: Which of the following is a primary pleural tumor?
- A. Mesothelioma (Correct Answer)
- B. Myxoma
- C. Lipoma
- D. None of the options
Explanation: ***Mesothelioma*** - Mesothelioma is a **primary malignant tumor** of the pleura [1], commonly associated with **asbestos exposure** [2]. - It typically presents with symptoms like **pleuritic chest pain**, dyspnea, and pleural effusion. *Myxoma* - Myxoma is a **benign tumor** primarily found in the **heart**, particularly in the left atrium, not in the pleura. - It does not arise from pleural tissue and lacks the **malignant characteristics** of mesothelioma. *All* - This option suggests that multiple tumors can be primary pleural tumors, which is incorrect as only mesothelioma is recognized as such. - Other tumors like myxoma and lipoma do not originate in the pleura and thus cannot be classified as primary pleural tumors. *Lipoma* - Lipoma is a **benign tumor** made up of adipose tissue [3] and is typically found in *subcutaneous tissue*, not the pleural cavity. - It does not have the malignant potential or association with pleural disease that characterizes mesothelioma. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 728-729. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Respiratory Tract Disease, pp. 339-340. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Bones, Joints, and Soft Tissue Tumors, p. 1222.
Question 6: Which histological type of lung cancer is most commonly associated with metastasis?
- A. Small cell carcinoma (Correct Answer)
- B. Squamous cell carcinoma
- C. Adenocarcinoma
- D. Large cell carcinoma
Explanation: ***Squamous cell CA*** - Known for its **aggressive nature** and propensity to metastasize, particularly in later stages. - Typically arises in the **central part of the lungs**, often associated with smoking and leads to local invasion and distant spread. *Alveolar-carcinoma* - Rarely found and tends to be **less aggressive** compared to squamous cell carcinoma. - Usually has a more localized effect without the same potential for widespread metastasis. *Small cell carcinoma* - Although it is **highly metastatic**, it is less common than squamous cell carcinoma in terms of overall lung cancer incidence. - Characterized by its rapid growth and early metastasis [1], but mostly associated with a specific subtype of lung cancer cases. *Adenocarcinoma* - Generally presents as a **peripheral lung lesion** and has **less propensity for early metastasis** compared to squamous cell carcinoma. - More common in non-smokers and tends to have a less aggressive metastatic pattern. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Respiratory Tract Disease, pp. 337-338.
Question 7: A 10yr old boy with a known case of nephrotic syndrome since 4 years on treatment brought to the pediatric OPD with chief complaint of difficulty in breathing. There is no history of fever. On examination, respiratory system was normal except slightly reduced breath sounds on right infra-axillary region. Paediatrician thinks of pleural effusion. What is next best modality of investigation to detect pleural effusion?
- A. Lateral view Chest X-ray
- B. USG (Correct Answer)
- C. Erect Chest X-ray PA view
- D. Lateral decubitus view
Explanation: ***USG*** - **Ultrasound** is the **best first-line investigation** for detecting **pleural effusions** in children due to its **non-invasive nature**, lack of radiation exposure, and ability to detect even small effusions (as little as 5-10 mL). - It can effectively differentiate between pleural fluid and other pathologies (e.g., consolidation, masses) and guide aspiration if needed. - **Real-time bedside availability** makes it ideal for pediatric patients. *Lateral view Chest X-ray* - A lateral Chest X-ray only detects pleural effusion if the fluid volume is at least **75-100 mL**, which might miss smaller effusions. - While it can provide additional information about the lungs and mediastinum, it is not as sensitive as ultrasound for detecting small effusions. *Erect Chest X-ray PA view* - An erect Chest X-ray PA view requires a minimum of **200-300 mL of fluid** to blunt the **costophrenic angle**, potentially missing smaller effusions. - It involves **ionizing radiation**, a concern in pediatric patients, and is less sensitive than ultrasound for early detection. *Lateral decubitus view* - A lateral decubitus view is useful for confirming the presence of **free-flowing pleural fluid** and differentiating it from loculated effusions, typically after an initial effusion is suspected. - While sensitive for detecting small effusions (as little as **50 mL**), it is typically performed as a secondary investigation and involves radiation exposure, unlike ultrasound.
Question 8: Which of the following has the minimal chance of causing mesothelioma?
- A. Amphibole
- B. Amosite
- C. Tremolite
- D. Chrysotile (Correct Answer)
Explanation: ***Crysolite*** - Crysolite, also known as **chrysotile**, has a significantly lower carcinogenic potential compared to other asbestos types like amphibole asbestos. - It is the most commonly used asbestos type but is associated with a **minimal risk of mesothelioma** [1]. *Amesolite* - Amesolite is an **amphibole asbestos** known to have a higher associated risk for mesothelioma due to its fiber structure [1]. - It has been implicated in **asbestosis** and lung cancer, making it a stronger carcinogen compared to crysolite. *Tremolite* - Tremolite is another type of **amphibole asbestos** that is highly toxic and strongly associated with mesothelioma [1]. - The **risk of malignant pleural mesothelioma** is significantly increased with exposure to tremolite fibers. *Ampholite* - Ampholite is a group of amphibole asbestos which has a high risk for both **lung cancers** and **mesothelioma** due to its fibrous nature [1]. - Similar to other amphibole types, it poses a greater carcinogenic risk than crysolite. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 697-698.
Question 9: TTF-1 (Thyroid Transcription Factor-1) immunohistochemical marker is most commonly seen in which of the following?
- A. Squamous Cell Carcinoma (SCC)
- B. Lung adenocarcinoma (Correct Answer)
- C. Large cell lung cancer
- D. Papillary thyroid carcinoma
Explanation: ***Lung adenocarcinoma*** - **TTF-1 (Thyroid Transcription Factor-1)** is a nuclear transcription factor that is highly expressed in adenocarcinomas of the lung. Positivity for TTF-1 is a key marker used in the diagnosis of primary lung adenocarcinoma, distinguishing it from other lung cancers and metastatic tumors. - While TTF-1 can also be positive in thyroid follicular and papillary carcinomas, its strong association with **lung adenocarcinoma** makes it a crucial diagnostic marker in this context, especially when differentiating between primary lung tumors and metastases or other lung cancer types. *Squamous Cell Carcinoma (SCC)* - **Squamous cell carcinoma of the lung** is generally **negative for TTF-1**. It typically expresses markers like p40 and CK5/6. - TTF-1 has very low sensitivity and specificity for squamous cell carcinoma, making it a poor choice for identifying this type of lung cancer. *Large cell lung cancer* - **Large cell lung carcinoma** is a diagnosis of exclusion and is typically **negative for TTF-1**, as well as other specific markers for adenocarcinoma or squamous cell carcinoma. - This type of cancer is characterized by large, anaplastic cells that lack features of other specific lung cancer types when viewed under a microscope. *Papillary thyroid carcinoma* - While **papillary thyroid carcinoma** is also **TTF-1 positive**, the question asks for the most common context in which TTF-1 is seen, and TTF-1 is a highly valuable marker for confirming a lung primary in the setting of lung masses. - TTF-1's utility in lung cancer diagnostics is particularly significant for differentiating primary lung adenocarcinomas from metastatic tumors and other lung cancer subtypes.
Question 10: In a patient with breast cancer, the following are poor prognostic factors except
- A. Aneuploid status
- B. Age less than 35 years
- C. High grade
- D. Absence of epidermal growth factor receptor (Correct Answer)
Explanation: ***Absence of epidermal growth factor receptor*** - The **absence of epidermal growth factor receptor (EGFR/HER1) overexpression** is associated with a **better prognosis** in breast cancer. - **EGFR overexpression** is more commonly seen in aggressive breast cancers, particularly **triple-negative breast cancers** (ER-negative, PR-negative, HER2-negative), and is associated with poor outcomes [2]. - When EGFR is absent or not overexpressed, the tumor tends to have less aggressive biological behavior. *Aneuploid status* - **Aneuploid status** (abnormal chromosome number) is a well-recognized **poor prognostic factor** in breast cancer, indicating genetic instability and aggressive tumor behavior [2]. - It is associated with **increased risk of recurrence** and poorer response to therapy. *Age less than 35 years* - **Younger age** (less than 35 years) at diagnosis is a **poor prognostic factor** for breast cancer. - This is often due to more aggressive tumor biology, **higher grade tumors**, hormone receptor negativity, and delayed diagnosis in younger women. *High grade* - A **high histological grade** (Grade III) indicates a more aggressive tumor with rapid cell division, marked nuclear pleomorphism, and poor differentiation, signifying a **poor prognosis** [1]. - High-grade tumors are more likely to metastasize and have higher recurrence rates. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 458-459. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Breast, pp. 1064-1066.
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