Pg Blazer - NEET Pg Mini Mock Test 1 (USMLE Based)

1. A 42-year-old woman, gravida 2, para 2, comes for a routine examination. She has type 2 diabetes mellitus well controlled with glyburide. She has a history of vulvar condylomata acuminata successfully treated with laser ablation 12 years ago. She does not smoke. She drinks a six-pack of beer nightly. She is sexually active and uses a diaphragm with spermicide for contraception. Her mother had breast cancer at the age of 65 years. The patient is 157 cm (5 ft 2 in) tall and weighs 100 kg (220 lb); BMI is 40 kg/m2. Physical examination shows no other abnormalities. Pelvic examination shows a 2-cm ulcer on the cervix. A biopsy specimen of the cervical lesion shows invasive squamous cell carcinoma. Which of the following is the most significant predisposing factor for this patient's cervical cancer?

Alcohol use

Diaphragm and spermicide use

Heredity

Human papillomavirus infection

Obesity

Parity

Type 2 diabetes mellitus

Human papilloma virus infection is the most important risk factor for development of cervical cancer.

Explanation

Human papilloma virus infection is the most important risk factor for development of cervical cancer.

2. A 55-year-old man who has alcoholic cirrhosis is brought to the emergency department because he has been vomiting blood for 2 hours. He has a 2-month history of abdominal distention, dilated veins over the anterior abdominal wall, and internal hemorrhoids. Which of the following veins is the most likely origin of the hematemesis?

Inferior mesenteric veins

Left gastric vein

Periumbilical veins

Superior rectal vein

Superior vena cava

This is a case of bleed from esophageal varices due to portal hypertension
Venous drainage from the esophagus occurs via 2 routes
Major portion of the blood is drained via esophageal veins which drain into the azygos vein which in turn drains into the superior vena cava.
These vessels have no role in development of varices
The remaining blood drains via the superficial veins in the esophageal mucosa into the left gastric vein which in turn drains into the portal vein
These vessels become dilated and form varices in portal hypertension

Explanation

This is a case of bleed from esophageal varices due to portal hypertension
Venous drainage from the esophagus occurs via 2 routes
Major portion of the blood is drained via esophageal veins which drain into the azygos vein which in turn drains into the superior vena cava.
These vessels have no role in development of varices
The remaining blood drains via the superficial veins in the esophageal mucosa into the left gastric vein which in turn drains into the portal vein
These vessels become dilated and form varices in portal hypertension

3. A 1-day-old newborn is evaluated for possible sepsis. Blood cultures grow gram-positive cocci in pairs and chains that agglutinate with group B antiserum. The most likely epidemiologic risk factor for this infection involves bacterial colonization of which of the following?

Mother’s vagina

Newborn’s gastrointestinal tract

Newborn’s nasopharynx

Placenta

Umbilical cord remnant

This is a case of early onset sepsis in a newborn. The organism involved is Group B streptococci (gram-positive cocci in pairs and chains that agglutinate with group B antiserum). The source of infection is probably the mother’s vagina.

Explanation

This is a case of early onset sepsis in a newborn. The organism involved is Group B streptococci (gram-positive cocci in pairs and chains that agglutinate with group B antiserum). The source of infection is probably the mother’s vagina.

4. A 52-year-old woman comes to the physician because of a 2-day history of fever and left flank pain. She has been treated for multiple episodes of pyelonephritis during the past 3 years. Her temperature is 37.8°C (100.1°F). Physical examination shows left flank tenderness. Urinalysis shows 12–18 WBC/hpf with occasional lymphocytes and mononuclear cells with features of macrophages. Cultures of urine grow 80,000 colonies/mL of Proteus mirabilis. An x-ray of the abdomen shows a 3-cm mass in the lower pole of the left kidney. Gross examination of the mass after it has been resected shows that it is yellow, 3.2-cm in diameter, and centrally but not marginally necrotic. Histologic examination of the mass shows a predominance of epithelioid cells with partially clear and granular-to-foamy cytoplasm. Nuclei are eccentric, normochromic, symmetric, and without significant pleomorphism. Scattered lymphocytes and plasma cells are intermixed. Which of the following is the most likely diagnosis?

Acute pyelonephritis

Malacoplakia

Renal cell carcinoma, clear cell type,intermediate grade

Renal cell carcinoma, granular cell type

Xanthogranulomatous pyelonephritis

The patient's history of recurrent pyelonephritis, fever, left flank pain, and the presence of Proteus mirabilis in the urine culture are consistent with a diagnosis of xanthogranulomatous pyelonephritis. The gross and histologic examination findings of a yellow, centrally necrotic mass with epithelioid cells containing partially clear and granular-to-foamy cytoplasm, along with the presence of lymphocytes and plasma cells, further support this diagnosis. Xanthogranulomatous pyelonephritis is a chronic inflammatory condition characterized by the destruction of renal parenchyma and the formation of granulomas containing lipid-laden macrophages.

Explanation

The patient's history of recurrent pyelonephritis, fever, left flank pain, and the presence of Proteus mirabilis in the urine culture are consistent with a diagnosis of xanthogranulomatous pyelonephritis. The gross and histologic examination findings of a yellow, centrally necrotic mass with epithelioid cells containing partially clear and granular-to-foamy cytoplasm, along with the presence of lymphocytes and plasma cells, further support this diagnosis. Xanthogranulomatous pyelonephritis is a chronic inflammatory condition characterized by the destruction of renal parenchyma and the formation of granulomas containing lipid-laden macrophages.

5. A 21-year-old man is brought to the emergency department by friends because of blurred vision, headache, abdominal pain, nausea, and vomiting for 30 minutes. His friends say that he drank 60 mL of wood alcohol 1 hour ago after a bet at a fraternity house party. His pulse is 58/min and regular, respirations are 28/min and shallow, and blood pressure is 130/72 mm Hg. Physical examination shows no other abnormalities. Laboratory studies show: Serum
Na+ – 139 mEq/L
Cl− – 85 mEq/L
K+ – 4.5 mEq/L
HCO3− – 13 mEq/L Urine
pH – 5
Crystals – none Arterial blood gas analysis on room air:
pH – 7.28
PO2 – 108 mm Hg
PCO2 – 22 mm Hg Which of the following is the most appropriate initial treatment for this patient?

Intravenous ethanol therapy

Intravenous sodium bicarbonate therapy

Oral acetylcysteine therapy

Oral activated charcoal therapy

Hemodialysis

This is a case of methyl alcohol posioning. Intravenous ethanol is administered to prevent toxicity and complications like blindness.

Explanation

This is a case of methyl alcohol posioning. Intravenous ethanol is administered to prevent toxicity and complications like blindness.

6. A 25-year-old woman has a 3-day history of vomiting and diarrhea. She has postural hypotension and poor tissue turgor. Her serum sodium concentration is 130 mEq/L. Which of the following findings is most likely?

Decreased serum aldosterone concentration

Increased serum atrial natriuretic peptide concentration

Increased effective circulating volume

Increased serum ADH (vasopressin) concentration

Urine osmolality less than serum osmolality

ADH secretion is increased during fluid depletion. Excluding the other options: A) Aldosterone’s function is to conserve water by increasing reabsorption. Hence the concentration will be increased. B) ANP is released in response to high BP to reduce water and sodium circulatory load. Hence it is not increased in this case. C) Since there is water loss with hypotension, circulating fluid volume will be low. E) Because body is conserving water urine osmolality will always be more than serum osmolality.

Explanation

ADH secretion is increased during fluid depletion. Excluding the other options: A) Aldosterone’s function is to conserve water by increasing reabsorption. Hence the concentration will be increased. B) ANP is released in response to high BP to reduce water and sodium circulatory load. Hence it is not increased in this case. C) Since there is water loss with hypotension, circulating fluid volume will be low. E) Because body is conserving water urine osmolality will always be more than serum osmolality.

7. A 72-year-old man who is a retired construction worker comes to the physician because he has had a lesion on his face for 3 months. Physical examination shows a 6-mm, red, ulcerated lesion with heaped borders. A biopsy specimen of the lesion shows atypical, dysplastic keratinocytes within the epidermis and dermis. Which of the following is the most likely diagnosis?

Actinic keratosis

Discoid lupus erythematosus

Melanoma

Mycosis fungoides

Squamous cell carcinoma

History of sun exposure (UV light), morphology and histology are characteristic of squamous cell carcinoma.

Explanation

History of sun exposure (UV light), morphology and histology are characteristic of squamous cell carcinoma.

8. A patient being treated with clindamycin for aspiration pneumonia develops diarrhea. The stool contains a toxin that kills cultured epithelial cells. Stool culture grows an anaerobic gram-positive rod. The same organism is cultured from his bedpan. Which of the following is most likely to sterilize the bedpan?

Boiling for 45 minutes

Exposure to benzalkonium chloride for 1 hour

Exposure to ethyl alcohol for 1 hour

Exposure to saturated steam (121°C) for 15 minutes

Heating in an oven at 150°C for 30 minutes

Proper autoclave treatment (Exposure to saturated steam (121°C) for 15 minutes) will inactivate all fungi, bacteria, viruses and also bacterial spores, which can be quite resistant. Although benzalkonium chloride is effective against the vegetative state, it is ineffective against the spores.

Explanation

Proper autoclave treatment (Exposure to saturated steam (121°C) for 15 minutes) will inactivate all fungi, bacteria, viruses and also bacterial spores, which can be quite resistant. Although benzalkonium chloride is effective against the vegetative state, it is ineffective against the spores.

9. Three weeks after traveling to California to study desert flowers, a 32-year-old man develops a fever, chest pain, and sore muscles. Two days later, red tender nodules appear on the shins, and the right ankle is painful and tender. An x-ray of the chest shows a left pleural effusion. Which of the following is the most likely diagnosis?

Blastomycosis

Coccidioidomycosis

Histoplasmosis

Mycobacterium marinum infection

Mycoplasma pneumoniae infection

Coccidioidomycosis – also known as “California disease”, “Desert rheumatism”, “San Joaquin valley fever” and “Valley fever” is a fungal disease caused by Coccidioides immitis or C. posadasii. The disease is usually mild, with flu-like symptoms and rashes. Serious complications include severe pneumonia, lung nodules, and disseminated disease, where the fungus spreads throughout the body. The disseminated form of valley fever can devastate the body, causing skin ulcers, abscesses, bone lesions, severe joint pain, heart inflammation, urinary tract problems, meningitis, and often death.

Explanation

Coccidioidomycosis – also known as “California disease”, “Desert rheumatism”, “San Joaquin valley fever” and “Valley fever” is a fungal disease caused by Coccidioides immitis or C. posadasii. The disease is usually mild, with flu-like symptoms and rashes. Serious complications include severe pneumonia, lung nodules, and disseminated disease, where the fungus spreads throughout the body. The disseminated form of valley fever can devastate the body, causing skin ulcers, abscesses, bone lesions, severe joint pain, heart inflammation, urinary tract problems, meningitis, and often death.

10. A 50-year-old man with a history of alcoholism has difficulty with short-term memory. He is unable to recall the date and cannot remember what he ate for breakfast this morning. He thinks the examiner is a long-lost friend and carries on a conversation with the examiner as if they have known each other for years. His long-term memory appears intact. The patient dies shortly thereafter of a myocardial infarct. Pathologic examination of his brain is most likely to disclose an abnormality involving which of the following?

Amygdala

Caudate nucleus

Hippocampus

Locus caeruleus

Mammillary bodies

The given history is suggestive of Wernicke’s encephalopathy (alcoholism, short term memory loss). The pathological changes seen in Wernicke’s encephalopathy are concentrated in the mammillary bodies, cranial nerve nuclei III, IV, VI and VIII, the thalamus, hypothalamus, periaqueductal grey, cerebellar vermis, and the dorsal nucleus of the vagus nerve.

Explanation

The given history is suggestive of Wernicke’s encephalopathy (alcoholism, short term memory loss). The pathological changes seen in Wernicke’s encephalopathy are concentrated in the mammillary bodies, cranial nerve nuclei III, IV, VI and VIII, the thalamus, hypothalamus, periaqueductal grey, cerebellar vermis, and the dorsal nucleus of the vagus nerve.