Pituitary Surgery — MCQs
A patient presents with large sweaty hands, macroglossia, and frontal bossing. What is the best test for confirmation of the diagnosis?
A lady comes to OPD after fall from scooty. Her vitals are stable. She is having continuous, clear watery discharge from nose after 2 days. This is most likely a feature of?
A patient with a known brain tumor learns that his pituitary stalk has been affected. Secretion of which of the following hormones is increased after the sectioning of the pituitary stalk?
Most common tumour of the pituitary is -
Which is the most common functioning tumour of pituitary?
What is the initial treatment for most patients with growth hormone-secreting pituitary adenoma?
A boy has developed epistaxis. What is the treatment of choice?
What is the most common space-occupying lesion in the cerebellopontine angle?
CSF rhinorrhea is most commonly seen in fracture of which of the following bones?
A patient, who underwent lateral skull base surgery a few months prior, presents with complaints of recurrent aspirations. There is no change in voice. Which of the following nerves is most likely injured during the surgery?
Pituitary Surgery Indian Medical PG Practice Questions and MCQs
Question 1: A patient presents with large sweaty hands, macroglossia, and frontal bossing. What is the best test for confirmation of the diagnosis?
- A. GHRH levels
- B. IGF-1 (Correct Answer)
- C. IGF-2
- D. GH levels after glucose suppression
- E. Random GH level
Explanation: ***IGF-1*** - Elevated **IGF-1 (Insulin-like Growth Factor 1)** is the most reliable screening test for acromegaly, reflecting integrated GH secretion over time. - The clinical signs of **large sweaty hands**, **macroglossia**, and **frontal bossing** are classic symptoms of acromegaly, caused by excessive growth hormone (GH) production, which then stimulates IGF-1. *GHRH levels* - **Growth hormone-releasing hormone (GHRH)** levels are typically only measured when investigating ectopic GHRH production as a rare cause of acromegaly, which is not the primary diagnostic step. - While GHRH stimulates GH, its direct measurement is not the standard initial diagnostic test for suspected pituitary-driven acromegaly. *IGF-2* - **IGF-2 (Insulin-like Growth Factor 2)** plays a role in fetal growth and certain tumor-related syndromes, but it is not the primary mediator or diagnostic marker for acromegaly in adults. - IGF-1, not IGF-2, is the main growth factor responsible for the anabolic effects of growth hormone. *GH levels after glucose suppression* - Measuring **GH levels after glucose suppression** (oral glucose tolerance test with 75g glucose) is a confirmatory test for acromegaly, used when IGF-1 levels are equivocal or borderline. - In healthy individuals, glucose suppresses GH secretion to <1 ng/mL, but in acromegaly, GH levels remain elevated (failure to suppress), confirming autonomous GH hypersecretion. *Random GH level* - **Random GH levels** are unreliable for diagnosing acromegaly due to the pulsatile nature of GH secretion, with significant variation throughout the day. - A single normal GH level does not exclude acromegaly, and a single elevated level can occur in healthy individuals during normal secretory peaks, making it inadequate as a diagnostic test.
Question 2: A lady comes to OPD after fall from scooty. Her vitals are stable. She is having continuous, clear watery discharge from nose after 2 days. This is most likely a feature of?
- A. CSF rhinorrhoea (Correct Answer)
- B. Acute respiratory infection
- C. Rhinitis
- D. Middle cranial fossa fracture
Explanation: ***CSF rhinorrhoea*** - **Clear watery discharge** appearing **two days after head trauma** (fall from scooty) is highly suggestive of **cerebrospinal fluid (CSF) rhinorrhoea**. - This occurs due to a breach in the **skull base**, allowing CSF to leak from the subarachnoid space into the nasal cavity. *Acute respiratory infection* - An acute respiratory infection typically presents with symptoms like **fever, cough**, and **nasal discharge** that is often thicker and discolored, not clear and watery. - The onset of discharge two days after trauma without other signs of infection also makes this less likely. *Rhinitis* - Rhinitis involves inflammation of the nasal mucosa, leading to watery discharge, sneezing, and congestion. - However, the traumatic etiology and the specific timing of the discharge make **CSF leak** a more pertinent diagnosis than simple rhinitis. *Middle cranial fossa fracture* - While a **middle cranial fossa fracture** can cause CSF leakage, the discharge from the nose (rhinorrhoea) typically originates from an **anterior cranial fossa fracture**. - A middle cranial fossa fracture is more commonly associated with **otorrhoea** (CSF leakage from the ear) if the temporal bone is involved.
Question 3: A patient with a known brain tumor learns that his pituitary stalk has been affected. Secretion of which of the following hormones is increased after the sectioning of the pituitary stalk?
- A. FSH
- B. Prolactin (Correct Answer)
- C. TSH
- D. ACTH
Explanation: ***Prolactin*** - Prolactin is **unique** among anterior pituitary hormones as it is under **tonic inhibitory control** by dopamine from the hypothalamus. - Sectioning of the pituitary stalk disrupts dopamine delivery via the hypothalamic-hypophyseal portal system. - This leads to a **loss of tonic inhibition**, causing an **increase in prolactin secretion** from the anterior pituitary. - This phenomenon is known as the **"stalk effect"** or **hyperprolactinemia due to stalk section**. *FSH* - **Follicle-stimulating hormone (FSH)** secretion is regulated by **gonadotropin-releasing hormone (GnRH)** from the hypothalamus, which is **stimulatory**. - Stalk section interrupts GnRH delivery via the portal system, leading to a **decrease** in FSH secretion. *TSH* - **Thyroid-stimulating hormone (TSH)** secretion is positively regulated by **thyrotropin-releasing hormone (TRH)** from the hypothalamus. - Interruption of the pituitary stalk reduces TRH delivery, causing a **decrease** in TSH secretion. *ACTH* - **Adrenocorticotropic hormone (ACTH)** secretion is positively regulated by **corticotropin-releasing hormone (CRH)** from the hypothalamus. - Damage to the pituitary stalk diminishes CRH stimulation, resulting in a **decrease** in ACTH secretion.
Question 4: Most common tumour of the pituitary is -
- A. ACTH secreting adenoma
- B. Prolactinoma (Correct Answer)
- C. TSH secreting adenoma
- D. GH secreting adenoma
Explanation: ***Prolactinoma*** - **Prolactinomas** are the most frequently occurring type of pituitary adenoma, accounting for approximately **40-50%** of all pituitary tumors [1]. - They are characterized by the **overproduction of prolactin**, leading to symptoms like **galactorrhea**, **amenorrhea**, and **infertility** [1]. *ACTH secreting adenoma* - This type of adenoma leads to **Cushing's disease** due to excessive **ACTH production**, stimulating adrenal cortisol synthesis [2]. - While significant, **ACTH-secreting adenomas** are less common than prolactinomas, accounting for about **15-20%** of pituitary tumors. *TSH secreting adenoma* - **TSH-secreting adenomas** are extremely rare, making up less than **1%** of all pituitary tumors. - They cause secondary hyperthyroidism due to excessive **thyroid-stimulating hormone (TSH)** secretion. *GH secreting adenoma* - **Growth hormone (GH) secreting adenomas** cause **acromegaly** in adults and **gigantism** in children [1]. - These tumors are less common than prolactinomas, constituting about **15-20%** of pituitary adenomas.
Question 5: Which is the most common functioning tumour of pituitary?
- A. GH secreting tumor
- B. ACTH producing adenoma
- C. Prolactinoma (Correct Answer)
- D. Oncocytoma
Explanation: ***Prolactinoma*** - Prolactinomas are the **most common type of functioning pituitary tumor**, accounting for approximately 40-50% of all pituitary adenomas [1]. - They lead to **hyperprolactinemia**, causing symptoms such as galactorrhea, amenorrhea, and infertility in women, and hypogonadism and erectile dysfunction in men [1]. *GH secreting tumor* - Growth hormone (GH) secreting tumors cause **acromegaly** in adults and **gigantism** in children [2]. - While significant, they are less common than prolactinomas, typically representing about 15-20% of functioning pituitary tumors. *ACTH producing adenoma* - ACTH producing adenomas lead to **Cushing's disease** via excessive cortisol production [3]. - These tumors are less frequent than prolactinomas, accounting for about 10-15% of functioning pituitary adenomas. *Oncocytoma* - Oncocytomas are a **histological classification** of tumors, not typically defined by specific hormone secretion. - Most pituitary oncocytomas are **non-functioning** and detected due to mass effect rather than hormonal excess.
Question 6: What is the initial treatment for most patients with growth hormone-secreting pituitary adenoma?
- A. Transphenoidal surgical resection (Correct Answer)
- B. Somatostatin analogs
- C. Dopamine agonists
- D. GH receptor antagonists
Explanation: ***Transphenoidal surgical resection*** - This is the **preferred initial treatment** for most growth hormone (GH)-secreting pituitary adenomas, as it offers the best chance for **cure** and rapid reduction in GH levels [1]. - Success rates are high, especially for **smaller tumors** (microadenomas), and it can quickly relieve mass effect symptoms [1]. *Somatostatin analogs* - These are typically used as **second-line therapy** if surgery is unsuccessful or contraindicated, or in patients not surgical candidates. - They work by **inhibiting GH secretion** but do not usually achieve a complete cure like surgery. *GH receptor antagonists* - These medications, such as pegvisomant, **block the action of GH** at its receptor, normalizing IGF-1 levels. - They are primarily used when other treatments, including surgery and somatostatin analogs, have failed to control GH excess. *Dopamine agonists* - While dopamine agonists (e.g., cabergoline) can **sometimes reduce GH secretion** in a minority of patients, they are significantly less effective for GH-secreting tumors compared to prolactinomas [1]. - They are occasionally used as **adjunctive therapy** or in specific cases where the GH-secreting tumor also co-secretes prolactin [1].
Question 7: A boy has developed epistaxis. What is the treatment of choice?
- A. Cauterization of vessels
- B. Surgical ligation
- C. Digital pressure (Correct Answer)
- D. Nasal packing
Explanation: ***Digital pressure*** - This is the **initial and most common first-line treatment** for acute epistaxis, especially in children, as most nosebleeds originate from Kiesselbach's plexus in the anterior septum. - Applying firm, continuous pressure to the soft part of the nose for 10-15 minutes can effectively compress the bleeding vessels and promote clot formation. *Cauterization of vessels* - This method is used when **digital pressure fails** to control the bleeding and the bleeding site can be identified, often in the anterior septum. - It involves using chemical (e.g., silver nitrate) or electrical methods to seal the bleeding vessel. *Surgical ligation* - **Surgical ligation** is reserved for severe, posterior epistaxis that is refractory to other methods like nasal packing or embolization. - It involves surgically tying off the major arteries supplying the nose (e.g., internal maxillary, external carotid) and carries greater risks. *Nasal packing* - **Nasal packing** is typically used when direct pressure has failed, and the bleeding site is not easily amenable to cauterization, or in cases of posterior epistaxis. - It involves inserting material into the nasal cavity to apply direct pressure to the bleeding vessel, but it is more invasive and uncomfortable than digital pressure.
Question 8: What is the most common space-occupying lesion in the cerebellopontine angle?
- A. Meningioma
- B. Glioma
- C. Neurofibroma
- D. Acoustic neuroma (Correct Answer)
Explanation: **Explanation:** The **Cerebellopontine Angle (CPA)** is a potential space in the posterior cranial fossa. The correct answer is **Acoustic Neuroma** (also known as Vestibular Schwannoma), which accounts for approximately **80–85%** of all CPA tumors. 1. **Acoustic Neuroma (Correct):** These are benign, slow-growing tumors arising from the Schwann cells of the vestibular nerve (most commonly the inferior vestibular nerve). They typically present with unilateral sensorineural hearing loss, tinnitus, and dysequilibrium. 2. **Meningioma (Incorrect):** This is the **second most common** CPA lesion, accounting for about 10–15% of cases. Unlike acoustic neuromas, they often do not widen the internal auditory canal (IAC) and may show calcification or a "dural tail" on MRI. 3. **Epidermoid Cyst (Incorrect):** These are the third most common CPA lesions (approx. 5%). They are congenital and characterized by a "pearly" appearance and restricted diffusion on MRI. 4. **Neurofibroma (Incorrect):** While associated with Neurofibromatosis Type 1, the tumors in the CPA (specifically in NF-2) are actually **Schwannomas**, not neurofibromas. 5. **Glioma (Incorrect):** These are primary brain parenchyma tumors (e.g., brainstem gliomas) and are rarely primary occupants of the CPA space. **NEET-PG High-Yield Pearls:** * **Gold Standard Investigation:** Contrast-enhanced MRI (Gadolinium) is the investigation of choice. * **Bilateral Acoustic Neuromas:** Pathognomonic for **Neurofibromatosis Type 2 (NF-2)**. * **Audiometry Finding:** Characterized by "Retrocochlear" pathology (Poor speech discrimination score out of proportion to pure tone loss and absence of recruitment). * **Order of Frequency in CPA:** Acoustic Neuroma > Meningioma > Epidermoid > Facial Nerve Schwannoma.
Question 9: CSF rhinorrhea is most commonly seen in fracture of which of the following bones?
- A. Cribriform plate (Correct Answer)
- B. Temporal bone
- C. Nasal bone
- D. Occipital bone
Explanation: **Explanation:** **Cribriform plate (Option A)** is the correct answer because it is the thinnest part of the anterior skull base and is intimately fused with the underlying dura mater. Due to this anatomical fragility, even minor head trauma can result in a dural tear. Since the cribriform plate forms the roof of the nasal cavity, any breach allows Cerebrospinal Fluid (CSF) to leak directly into the nose, manifesting as **CSF rhinorrhea**. **Analysis of Incorrect Options:** * **Temporal bone (Option B):** Fractures here (especially longitudinal) more commonly lead to **CSF otorrhea** (leakage through the ear). While CSF rhinorrhea can occur if the tympanic membrane is intact and fluid drains via the Eustachian tube, it is statistically less common than leaks from the anterior cranial fossa. * **Nasal bone (Option C):** These are the most common facial fractures, but they are extracranial. Unless the fracture extends superiorly into the frontal or ethmoid bones, it does not involve the dural sac. * **Occipital bone (Option D):** Fractures here involve the posterior cranial fossa. These are more likely to cause cranial nerve palsies or cerebellar injury rather than rhinorrhea. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of spontaneous CSF leak:** Tegmen tympani or Ethmoid roof. * **Most common site of traumatic CSF leak:** Cribriform plate/Ethmoid bone. * **Confirmatory Test:** **Beta-2 Transferrin** (most specific) or Beta-trace protein. * **Target Sign/Halo Sign:** Seen when CSF is mixed with blood on a paper/linen (CSF migrates further, forming a clear outer ring). * **Management:** Initial conservative management (bed rest, head elevation, avoiding straining). If persistent, endoscopic endonasal repair is the gold standard.
Question 10: A patient, who underwent lateral skull base surgery a few months prior, presents with complaints of recurrent aspirations. There is no change in voice. Which of the following nerves is most likely injured during the surgery?
- A. Vagus nerve
- B. Glossopharyngeal nerve
- C. Superior Laryngeal Nerve (SLN) (Correct Answer)
- D. Recurrent Laryngeal Nerve (RLN)
Explanation: **Explanation:** The key to this question lies in the dissociation between sensory loss and motor function of the vocal cords. **1. Why Superior Laryngeal Nerve (SLN) is correct:** The SLN divides into the Internal and External branches. The **Internal Laryngeal Nerve** provides sensory innervation to the laryngeal mucosa above the vocal folds. Injury to this nerve leads to **laryngeal anesthesia**, causing a loss of the cough reflex when food or liquid enters the laryngeal inlet. This results in **recurrent silent aspirations**. Since the External branch only supplies the cricothyroid muscle (which tenses the vocal cords), its injury may cause a slight change in pitch but **no hoarseness or loss of voice**, matching the clinical presentation. **2. Why other options are incorrect:** * **Vagus Nerve (Main Trunk):** Injury would involve both the SLN and RLN, leading to both aspiration and significant voice changes (vocal cord paralysis). * **Glossopharyngeal Nerve (CN IX):** While it mediates the gag reflex and oropharyngeal sensation, isolated injury is less likely to cause recurrent aspiration without dysphagia or loss of taste in the posterior third of the tongue. * **Recurrent Laryngeal Nerve (RLN):** This nerve provides motor supply to all intrinsic muscles of the larynx (except the cricothyroid). Injury would cause **vocal cord palsy**, leading to a breathy voice or hoarseness, which is absent in this patient. **Clinical Pearls for NEET-PG:** * **Internal Laryngeal Nerve:** "The Watchdog of the Larynx"—its loss leads to aspiration. * **Cricothyroid Muscle:** The only intrinsic laryngeal muscle supplied by the External Laryngeal Nerve; it is the "tuning fork" (increases pitch). * **Lateral Skull Base Surgery:** High risk for "Lower Cranial Nerve" (IX, X, XI, XII) palsies. Always check for the "Curtain Sign" (deviation of the posterior pharyngeal wall) to assess CN IX and X.
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