Usmle – tests

1. A 69-year-old male with a 45 pack-year smoking history presents with hemoptysis, 20 lb. weight loss, and proximal muscle weakness that improves throughout the day. A bronchoscopy reveals malignant cells with dark nuclei and little cytoplasm. Which of the following is the most likely diagnosis?

A. Adenocarcinoma of the lung
B. Mesothelioma
C. Non-Hodgkin’s lymphoma
D. Small cell lung cancer
E. Squamous cell lung cancer

See Explanation
D is the correct answer.
(82% of users answered this question correctly)

Both small cell and squamous cell cancer of the lung are strongly linked to smoking history and often present with paraneoplastic syndromes. Small cell cancer can present with Lambert-Eaton Syndrome, a type of paraneoplastic syndrome which resembles myasthenia gravis, although symptoms generally improve over the course of the day, while they worsen in myasthenia. The other cancers listed are not commonly associated with

paraneoplastic syndromes.

2. A 25-year-old woman presents with 6 months of lethargy, sensitivity to cold temperatures, and an elevated serum TSH. What is the most appropriate management for this patient?

A. Fluoxetine
B. Hydrocortisone
C. Levothyroxine
D. Propylthiouracil
E. Radioactive iodine treatment

See Explanation
C is the correct answer.
(93% of users answered this question correctly)

This woman complains of symptoms of hypothyroidism with an elevated TSH. Levothyroxine, a synthetic form of thyroid hormone, is the most appropriate choice.

(A) Fluoxetine is an SSRI could be used for depression. Serum TSH would be normal in depression.

(B) Hydrocortisone is a steroid that could be used for Addison’s Disease (chronic adrenal insufficiency). Serum TSH should be normal in Addison’s.

(D) Propylthiouracil and (E) radioactive iodine treatment are used in hyperthyroidism. Serum TSH would be low in hyperthyroidism. Propylthiouracil inhibits the enzyme thyroperoxidase, thus resulting in decreased thyroxine production. It also inhibits the peripheral deiodination of T4 to T3 (T3 is more active). In radioactive iodine treatment, there is thyroid uptake of the radioactive isotope iodine-131, which results in cytotoxic radiation delivered to some thyroid cells.

3. A 22-year-old college student that is confused and lethargic is brought to the emergency room. His roommates say he was complaining of a severe headache and neck stiffness last night. Vital signs are remarkable for a temperature of 104.3, blood pressure of 80/60 and heart rate of 120. Physical exam reveals a purpuric rash on the patient’s chest. Lumbar puncture reveals a high neutrophil count.
What treatment should be given to his roommates as prophylaxis?

A. Acyclovir
B. Ceftriaxone
C. Doxycycline
D. Rifampin
E. Vancomycin

See Explanation
D is the correct answer.
(60% of users answered this question correctly)

The patient described has acute bacterial meningitis, the cause of which is most likely N. meningitidis (given the patients age, clinical history, and the characteristic purpuric rash of DIC.) Rifampin is indicated for prophylaxis of close contacts of patients with meningococcal meningitis.
Ceftriaxone is indicated for the treatment of meningococcal meningitis, but not the prophylaxis of contacts.

Vancomycin is not indicated in this situation as it only covers gram positive organisms.

Acyclovir is also not indicated in this situation as the lumbar puncture results suggest this patient’s meningitis is bacterial and not due to a virus.

Usmle – tests