Q-51. The diagnostic method of choice for Hirschprung disease is
a) Rectal biopsy
b) Manometry
c) Contrast enema
d) MRI
Answer: Rectal biopsy
Explanation:
During normal fetal development, cells from the neural crest migrate into the large intestine (colon) to form the networks of nerves called Auerbach’s plexus and Meissner’s plexus. In Hirschsprug’s disease, the migration is not complete and part of the colon lacks these nerve bodies that regulate the activity of the colon.
Diagnostic techniques involve ano-rectal manometry, barium enema, and rectal biopsy.
The suction rectal biopsy is considered the current international gold standard in the diagnosis of Hirschsprug’s disease.
A histologic examination of the tissue would show a lack of ganglionic nerve cells.
Q-52. Renal stone associated with Proteus infection
a) Uric acid
b) Xanthine
c) Calcium oxalate
d) Triple phosphate
Answer: Triple phosphate
Explanation:
Urinary infection with urea-splitting bacteria, lead to formation of stones called infection stones or phosphate stones (Calcium phosphate and magnesium ammonium phosphate also called triple phosphate or struvite).
The most common urea-splitting bacteria are called Proteus mirabilis.
Infection stones can grow very large and fill the entire kidney. These large stones are called “stag-horn” stones because they resemble the branched horns of a male deer.
Q-53. Most common tumor in the posterior mediastinum is
a) Neurofibroma
b) Teratoma
c) Lymphoma
d) Bronchogenic cyst
Answer: Neurofibroma
Explanation:
The most common mediastinal masses are neurogenic tumors (20% of mediastinal tumors), usually found in the posterior mediastinum, followed by thymoma (15-20%) located in the anterior mediastinum.
Most common tumor in the posterior mediastinum is neurogenic in origin, and in adults is neural sheath origin including neurilemomas and neurofibromas.
Q-54. All of the following are components of the MEN type 2B syndrome except:
a) Multiple neuromas on the lips, tongue, and oral mucosa
b) Hyperparathyroidism
c) Medullary thyroid carcinoma
d) Pheochromocytoma
Answer: Hyperparathyroidism
Explanation:
Type 2 multiple endocrine neoplasia (MEN 2) is a rare familial cancer syndrome caused by mutations in the RET proto-oncogene. Sipple first described an association between thyroid cancer and pheochromocytoma.
Multiple Endocrine Neoplasia (MEN): Incidence of tumor types
MEN 1 (Wermer Syndrome):
Parathyroid
Pancreatic
Pituitary
Thyroid adenoma
Facial angio-fibromas and collagenomas
MEN 2A (Sipple Syndrome):
Medullary thyroid carcinoma
Pheochromocytoma
Parathyroid
MEN 2B:
Mucosal and GI Ganglio-neuroma
Medullary thyroid carcinoma
Pheochromocytoma
Q-55. MEN 2A and MEN 2B syndromes are associated with germline mutations in:
A. The p53 tumor suppressor gene.
b) H-ras gene.
c) N-myc gene.
d) RET proto-oncogene
Answer: RET proto-oncogene
Explanation:
See above explanation
Q-56. A 35-year-old man has known ulcerative colitis. Which of the following is an indication for total procto-colectomy?
a) Occasional bouts of colic and diarrhea
b) Sclerosing cholangitis
c) Toxic mega-colon
d) Arthritis
e) Iron deficiency anemia
Answer: Toxic mega-colon
Explanation:
Toxic mega-colon is a fulminant exacerbation of ulcerative colitis, causing massive dilatation of the colon with perforation, fecal peritonitis, and death. Emergency total colectomy is indicated.
Q-57. Orchidectomy is not done in
a) Prostate cancer
b) Seminoma
c) Male breast cancer
d) Filarial epididymo-orchitis
Answer: Filarial epididymo-orchitis
Explanation:
Orchidectomy is not done in filarial epididymo-orchitis and treated with DEC.
Orchidectomy is done in male breast cancer to induce remission of metastatic disease.
Prostate cancer and seminoma are well known indication for Orchidectomy.
Prostate cancer- Orchidectomy is done for androgen ablation
Seminoma- Orchidectomy is done for curative as well as diagnostic
Q-58. Most common site of lentigo maligna melanoma is
a) Face
b) Legs
c) Trunks
d) Sole
Answer: Face
Explanation:
Lentigo maligna (LM) is a subtype of melanoma in situ, and it has a slight female preponderance.
Lentigo maligna and lentigo maligna melanoma are associated with higher occupational exposure and lower recreational sun exposure.
Lentigo maligna melanoma is most often found in the head and neck.
In most cases, lentigo maligna should undergo surgical excision.
Other treatments for lentigo maligna may be considered if it is difficult to remove the lesion surgically, or surgery will be very deforming, or there is a major contraindication to surgery: Radiotherapy, Cryotherapy and Imiquimod cream – not yet fully evaluated.
However, these treatments do not offer as high cure rates as complete surgical excision.
Q-59. Parathyroid adenoma most commonly involves which of the following sites
a) Superior parathyroid lobe
b) Inferior parathyroid lobe
c) In the mediastinum
d) In the thyroid
Answer: Inferior parathyroid lobe
Explanation:
Primary hyperparathyroidism (HPT) is a condition characterized by an inappropriate excess of parathyroid hormone (PTH) secretion.
The elevated PTH levels result in hyper-calcemia and hypophosphatemia, with associated medical comorbidities including calculus formation, bone and abdominal pain, polyuria, and depression.
Primary HPT is caused by a single parathyroid adenoma in 90% of patients and multi-gland disease in approximately 10%. Rarely, patients may develop hyperparathyroidism secondary to a parathyroid carcinoma.
The most common site of adenoma is the left inferior parathyroid gland.
Q-60. All of the following are indications for surgery in gastric lymphoma except
a) Bleeding
b) Perforation
c) Intractable pain
d) Residual disease following chemotherapy
Answer: Residual disease following chemotherapy
Explanation:
Surgery plays an important role in the management of gastric lymphoma for the following reasons:
- Removing the lesion relieves symptoms and improves survival;
- Surgery allows not only a correct histological diagnosis but also the accurate staging of the disease;
- It prevents severe complications such as bleeding or perforation.