General Surgery Principles Practice Questions

Q: What is the most common lesion found in the middle mediastinum?

Congenital cyst. **Explanation:** The mediastinum is traditionally divided into anterior, middle, and posterior compartments. The **middle mediastinum** contains the heart, pericardium, great vessels, trachea, and major bronchi. **Why "Congenital Cyst" is correct:** Congenital cysts are the most common primary lesions of the middle mediastinum. These include **bronchogenic cysts** (most common), pericardial cysts, and enteric cysts. They arise from abnormal budding of the primitive foregut during embryogenesis. On imaging, they typically appear as well-circumscribed, fluid-filled masses near the carina or paratracheal region. **Analysis of Incorrect Options:** * **Lipoma (A):** While lipomas can occur anywhere in the mediastinum, they are rare and most frequently found in the anterior mediastinum or cardiophrenic angles. * **Aneurysm (B):** Aortic aneurysms are common vascular pathologies of the middle mediastinum; however, they are categorized as vascular abnormalities rather than primary mediastinal "lesions" or tumors. * **Germ Cell Tumour (D):** These (along with the "4 Ts": Thymoma, Teratoma, Thyroid, and Terrible Lymphoma) are the hallmark lesions of the **Anterior Mediastinum**. **High-Yield Clinical Pearls for NEET-PG:** * **Anterior Mediastinum:** Most common site for mediastinal masses overall. Most common lesion: **Thymoma**. * **Middle Mediastinum:** Most common lesion: **Congenital/Bronchogenic Cyst**. Lymphadenopathy (sarcoid, lymphoma, or metastasis) is also frequently seen here. * **Posterior Mediastinum:** Most common lesion: **Neurogenic tumours** (e.g., Schwannoma, Neurofibroma). * **Imaging Gold Standard:** Contrast-Enhanced Computed Tomography (CECT) is the investigation of choice for characterizing mediastinal masses.

Q: Which tumour is not typically found in the anterior mediastinum?

Neurofibroma. ### Explanation The mediastinum is anatomically divided into compartments, each associated with specific characteristic pathologies. The **anterior mediastinum** is the space bounded by the sternum anteriorly and the pericardium/great vessels posteriorly. #### Why Neurofibroma is the Correct Answer **Neurofibroma** is a nerve sheath tumor. In the mediastinum, neurogenic tumors (including neurofibromas, schwannomas, and ganglioneuromas) are almost exclusively found in the **posterior mediastinum**, arising from the paravertebral sympathetic chain or intercostal nerves. Therefore, it is not a typical finding in the anterior compartment. #### Analysis of Incorrect Options (The "4 Ts" of Anterior Mediastinum) The differential diagnosis for an anterior mediastinal mass is classically remembered by the mnemonic **"The 4 Ts"**: * **Thymic Tumours (Option B):** The most common primary anterior mediastinal neoplasm in adults (e.g., Thymoma, Thymic carcinoma). * **Teratoma (Option A):** Represents Germ Cell Tumors (GCTs). Mature teratomas are the most common GCTs found in this region. * **Thyroid Tumours (Option C):** Specifically "Retrosternal Goiter." Ectopic thyroid tissue or an extension of a cervical goiter frequently occupies the superior-anterior mediastinum. * **"Terrible" Lymphoma:** The fourth "T," often presenting with bulky lymphadenopathy. #### NEET-PG High-Yield Pearls * **Most common mediastinal mass overall:** Neurogenic tumors (but specifically in the **posterior** compartment). * **Most common anterior mediastinal mass:** Thymoma. * **Imaging Gold Standard:** Contrast-Enhanced CT (CECT) is the investigation of choice to delineate the compartment and characteristics of the mass. * **Myasthenia Gravis Association:** Approximately 15% of patients with Myasthenia Gravis have a thymoma, while 65-75% have thymic hyperplasia.

Q: Which one of the following conditions can complicate as hyperchloremic acidosis?

Ureterosigmoidostomy. **Explanation:** **Hyperchloremic Metabolic Acidosis (Normal Anion Gap Acidosis)** occurs when there is a loss of bicarbonate ($HCO_3^-$) from the body, which is compensated by an increase in serum chloride ($Cl^-$) to maintain electroneutrality. **1. Why Ureterosigmoidostomy is Correct:** In this surgical procedure, the ureters are diverted into the sigmoid colon. The colonic mucosa is exposed to urine for prolonged periods. The intestinal epithelium actively reabsorbs chloride ions from the urine in exchange for bicarbonate ions (via the $Cl^-/HCO_3^-$ exchanger). This chronic loss of bicarbonate into the urine and excessive absorption of chloride leads to **Hyperchloremic Metabolic Acidosis**. **2. Analysis of Other Options:** * **Vomiting:** Causes loss of gastric $HCl$, leading to **Hypochloremic Metabolic Alkalosis**. * **Ileoplasty:** While urinary diversions using ileal segments (like an Ileal Conduit) can cause similar electrolyte shifts, the surface area and contact time in a sigmoid diversion are significantly higher, making Ureterosigmoidostomy the classic textbook association for this complication. * **Diarrhea:** While diarrhea *does* cause hyperchloremic metabolic acidosis (due to loss of alkaline intestinal secretions), **Ureterosigmoidostomy** is the more specific surgical complication often tested in this context. *Note: In many clinical scenarios, both B and D are correct, but B is the classic surgical "high-yield" answer.* **Clinical Pearls for NEET-PG:** * **Mnemonic for Normal Anion Gap Acidosis (USED CARP):** **U**reterosigmoidostomy, **S**aline infusion, **E**ndocrine (Addison’s), **D**iarrhea, **C**arbonic anhydrase inhibitors, **A**mmonium chloride, **R**enal tubular acidosis, **P**ancreatic fistula. * **Ureterosigmoidostomy** is rarely performed today due to this metabolic risk and the long-term risk of **adenocarcinoma** at the site of anastomosis.

Q: True about malignant melanoma?

Lymphatic spread. **Explanation:** **Malignant Melanoma** is a highly aggressive cutaneous malignancy arising from melanocytes. **1. Why Option A is Correct:** The most common route of initial metastasis for malignant melanoma is via the **lymphatics** to regional lymph nodes. While hematogenous spread occurs later (leading to distant metastases in the lungs, liver, and brain), the predictable lymphatic progression is the basis for staging and surgical management. **2. Why Other Options are Incorrect:** * **Option B:** Lymph node biopsy (specifically Sentinel Lymph Node Biopsy - SLNB) is **not always done**. It is generally indicated for intermediate-thickness lesions (Breslow thickness 0.8 mm to 4.0 mm) or thinner lesions with high-risk features (e.g., ulceration). It is not required for *in situ* melanoma or very thin lesions (<0.8 mm). * **Option C:** Modern surgical practice has shifted away from routine **Completion Lymph Node Dissection (CLND)** even if the sentinel node is positive. Large trials (MSLT-II) showed that CLND improves regional control but does not improve overall survival compared to nodal observation with ultrasound. * **Option D:** While **Microsatellitism** (microscopic nests of tumor cells near the primary lesion) is a known pathological feature and a poor prognostic indicator, it is a *feature* of the disease rather than a defining "true" statement in the context of general surgical principles compared to the primary mode of spread. **High-Yield Clinical Pearls for NEET-PG:** * **Breslow Depth:** The most important prognostic factor (measured from the granular layer to the deepest tumor cell). * **ABCDE Criteria:** Asymmetry, Border irregularity, Color variegation, Diameter >6mm, Evolving. * **Commonest Site:** Back in men; Lower limbs in women. * **Most Common Subtype:** Superficial Spreading Melanoma. * **Most Aggressive Subtype:** Nodular Melanoma.

Q: Multiple pencil ulcers are seen in all except?

Carcinomatous ulcers. **Explanation:** The term **"Pencil Ulcers"** (also known as "punched-out" or "shallow" ulcers) refers to multiple, small, discrete, and painful ulcerations typically seen in inflammatory or infective conditions of the oral mucosa. **Why Carcinomatous Ulcer is the Correct Answer:** Carcinomatous ulcers (Malignant ulcers) are characterized by an **everted (rolled-out) edge** and a hard, **indurated base**. They are typically **solitary**, progressive, and painless in the early stages. They do not present as multiple small "pencil" ulcers; instead, they represent a single focus of uncontrolled cellular proliferation and tissue destruction. **Analysis of Incorrect Options:** * **Aphthous Ulcers:** These are the most common cause of multiple small, painful, shallow ulcers with a yellowish-grey floor and a surrounding red halo. They fit the "pencil ulcer" description perfectly. * **Herpes Ulcers:** Viral infections like Herpes Simplex (Herpetic Gingivostomatitis) present as clusters of small vesicles that rupture to form multiple, shallow, "punched-out" circular ulcers. * **Tuberculous Ulcers:** While rare, secondary TB of the oral cavity presents as multiple, shallow, extremely painful ulcers with **undermined edges**. In clinical practice, these are often grouped with small, multiple inflammatory ulcers. **NEET-PG High-Yield Pearls:** * **Edge Characteristics:** * *Everted:* Squamous Cell Carcinoma. * *Undermined:* Tuberculosis. * *Punched-out:* Syphilis (Gummatous) or Trophic ulcers. * *Sloping:* Healing ulcer. * *Rolled-in/Beaded:* Basal Cell Carcinoma (Rodent ulcer). * **Induration** is the clinical hallmark of malignancy. * **Aphthous ulcers** are associated with HLA-B51 (Behçet’s disease).

Q: In a multilayered wound, the deep layer is sutured by chromic gut. This is done because chromic gut sutures have:

Delayed resorption. **Explanation:** The correct answer is **C. Delayed resorption.** **Medical Concept:** Chromic gut is a natural absorbable suture derived from the submucosa of sheep intestine or serosa of bovine intestine. Plain catgut is absorbed rapidly (7–10 days) due to proteolytic enzymatic digestion. To improve its clinical utility, the gut is treated with **chromium salts (chromic acid)**. This treatment causes cross-linking of collagen fibers, which makes the suture more resistant to enzymatic degradation. Consequently, chromic gut maintains its tensile strength for a longer period (14–21 days) and takes longer to be completely resorbed (up to 90 days) compared to plain gut. In multilayered closures, the deep layers require prolonged support to prevent dehiscence while the tissue heals. **Analysis of Incorrect Options:** * **A. Increased strength:** While chromic treatment preserves strength for a longer duration, it does not significantly increase the initial knot-pull strength compared to plain gut of the same gauge. * **B. Increased ease of use:** Chromic gut is often stiffer and has more "memory" than plain gut, making it slightly more difficult to handle and knot securely. * **D. Less tissue irritation:** Being a foreign animal protein, chromic gut actually causes a **marked inflammatory tissue reaction**. Synthetic absorbable sutures (like Vicryl) are preferred when minimal irritation is required. **High-Yield NEET-PG Pearls:** * **Mechanism of Absorption:** Natural sutures (Gut) are absorbed by **proteolysis/enzymatic digestion**, whereas synthetic sutures (Vicryl, PDS) are absorbed by **hydrolysis**. * **Contraindication:** Never use chromic gut in infected tissues or the biliary/urinary tracts, as it can act as a nidus for stone formation or degrade prematurely. * **Fastest absorbing suture:** Plain catgut. * **Longest strength retention (Absorbable):** PDS (Polydioxanone).

Q: Which type of ulcer is likely to develop in a long-standing chronic venous ulcer?

Marjolin ulcer. ### Explanation **Correct Answer: A. Marjolin ulcer** A **Marjolin ulcer** refers to a squamous cell carcinoma (SCC) that arises in areas of chronic inflammation, long-standing scars, or non-healing wounds. The most common precursors are **chronic venous stasis ulcers**, old burn scars (cicatrix), and chronic osteomyelitis sinuses. The underlying pathophysiology involves constant cellular turnover and chronic irritation, which eventually leads to malignant transformation. These ulcers are typically painless (as they destroy local sensory nerves) but are characterized by everted edges and a foul-smelling discharge. **Why the other options are incorrect:** * **B. Aphthous ulcer:** These are small, painful, shallow ulcers found on the mucous membranes of the mouth (canker sores). They are not associated with chronic venous disease or malignancy. * **C. Bazin ulcer (Erythema Induratum):** This is a form of panniculitis (inflammation of subcutaneous fat) associated with Tuberculosis. It typically presents as tender, nodules on the calves of young women that may ulcerate. * **D. Aerial ulcer:** This is not a standard medical term for a specific type of chronic or malignant ulcer. **High-Yield Clinical Pearls for NEET-PG:** * **Most common histological type:** Squamous Cell Carcinoma (SCC) is the most frequent, though Basal Cell Carcinoma (BCC) can rarely occur. * **Characteristic Feature:** Marjolin ulcers are generally **more aggressive** and have a higher rate of metastasis compared to primary SCC of the skin. * **Diagnosis:** Any chronic ulcer showing sudden growth, everted edges, or bleeding should undergo an **edge biopsy** to rule out malignancy. * **Latency:** The average time for malignant transformation is 25–30 years.

Q: Splenectomy is indicated in:

Hereditary spherocytosis. **Explanation:** **Hereditary Spherocytosis (HS)** is the correct answer because it is the most common hemolytic anemia for which splenectomy is indicated. In HS, a defect in red blood cell (RBC) membrane proteins (like spectrin or ankyrin) results in spherical, rigid cells. These spherocytes are prematurely trapped and destroyed by splenic macrophages in the cords of Billroth. Splenectomy does not cure the membrane defect but significantly increases RBC lifespan, effectively resolving the anemia and preventing complications like pigment gallstones. **Why other options are incorrect:** * **Sickle Cell Anemia:** Splenectomy is rarely indicated because these patients undergo "autosplenectomy" due to repeated infarctions by early childhood. Surgery is only considered for specific complications like acute splenic sequestration or a rare splenic abscess. * **Haemoglobin C Disease:** This usually presents as a mild hemolytic anemia that rarely requires surgical intervention. * **Hodgkin’s Lymphoma:** Historically, "staging laparotomy" with splenectomy was common. However, with modern PET-CT imaging and advanced chemotherapy protocols, splenectomy is no longer a standard part of management. **Clinical Pearls for NEET-PG:** * **Timing:** In HS, splenectomy is ideally deferred until age 5–6 to reduce the risk of Overwhelming Post-Splenectomy Infection (OPSI). * **Vaccination:** Patients must receive vaccinations against encapsulated organisms (*S. pneumoniae, H. influenzae, N. meningitidis*) at least 2 weeks before elective surgery. * **Peripheral Smear:** Post-splenectomy, look for **Howell-Jolly bodies**, Pappenheimer bodies, and Heinz bodies. * **Concomitant Procedure:** Always screen for gallstones in HS patients; if present, a cholecystectomy should be performed during the same session.

Question 1

What is the most common lesion found in the middle mediastinum?

Accepted Answer

Congenital cyst

Answer

Lipoma

Answer

Aneurysm

Answer

Germ cell tumour

Question 2

Which statement is true regarding a hydatid cyst of the lung?

Accepted Answer

More common in lower lobes.

Answer

Never ruptures.

Answer

Calcification is common.

Answer

Always associated with a cyst in the liver.

Question 3

Which tumour is not typically found in the anterior mediastinum?

Accepted Answer

Neurofibroma

Answer

Teratoma

Answer

Thymic tumours

Answer

Thyroid tumours

Question 4

Which one of the following conditions can complicate as hyperchloremic acidosis?

Accepted Answer

Ureterosigmoidostomy

Answer

Vomiting

Answer

Ileoplasty

Answer

Diarrhoea

Question 5

Which of the following is most ideal when sealing a vessel?

Accepted Answer

Continuous low-voltage waveforms

Answer

Continuous high-voltage waveforms

Answer

Intermittent low-voltage waveforms

Answer

Intermittent high-voltage waveforms

Question 6

True about malignant melanoma?

Accepted Answer

Lymphatic spread

Answer

Lymph node biopsy is always done

Answer

Block dissection is done when sentinel node is involved

Answer

Microsatellitism

Question 7

Multiple pencil ulcers are seen in all except?

Accepted Answer

Carcinomatous ulcers

Answer

Aphthous ulcers

Answer

Herpes ulcers

Answer

Tuberculous ulcers

Question 8

In a multilayered wound, the deep layer is sutured by chromic gut. This is done because chromic gut sutures have:

Accepted Answer

Delayed resorption

Answer

Increased strength

Answer

Increased ease of use

Answer

Less tissue irritation

Question 9

Which type of ulcer is likely to develop in a long-standing chronic venous ulcer?

Accepted Answer

Marjolin ulcer

Answer

Aphthous ulcer

Answer

Bazin ulcer

Answer

Aerial ulcer

Question 10

Splenectomy is indicated in:

Accepted Answer

Hereditary spherocytosis

Answer

Sickle cell anaemia

Answer

Haemoglobin C disease

Answer

Hodgkin's lymphoma

General Surgery Principles — MCQs

General Surgery Principles — MCQs

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