MD - Doctor of Medicine Hematology and Oncology Questions and Answers

Question 1

A 28-year-old woman of Mediterranean descent presents with lifelong mild fatigue. A CBC reveals: Hgb 10.5 g/dL, MCV 65 fL, RBC 5.8 million/µL, and a normal RDW. Iron studies show a serum ferritin of 80 ng/mL and a transferrin saturation of 30%. Which of the following is the most likely diagnosis?

Accepted Answer

Beta-thalassemia trait

Answer

The patient presents with microcytic anemia (MCV < 80 fL). Key differentiating features point towards thalassemia trait: a markedly low MCV with a disproportionately high RBC count, a normal RDW, and normal iron studies. The Mentzer Index (MCV/RBC) is < 13 (65/5.8 ≈ 11.2), which is highly suggestive of thalassemia trait rather than iron deficiency anemia, where it is typically > 13. Her Mediterranean ancestry also increases the pre-test probability for beta-thalassemia.

Question 2

A 62-year-old male is undergoing surveillance after a curative resection for Stage III colon cancer one year ago. Which of the following tumor markers is most appropriate to monitor for disease recurrence in this patient?

Accepted Answer

Carcinoembryonic antigen (CEA)

Answer

Carcinoembryonic antigen (CEA) is the standard tumor marker used for surveillance in patients with a history of colorectal cancer after curative treatment. A rising CEA level on serial testing can be the first sign of disease recurrence and should prompt further imaging and investigation. CA 19-9 is associated with pancreatic cancer, AFP with hepatocellular carcinoma and certain germ cell tumors, and PSA with prostate cancer.

Question 3

A 10-year-old boy presents with recurrent episodes of painful, swollen joints (hemarthrosis), particularly in his knees and ankles, after minor trauma. His laboratory studies show a prolonged activated partial thromboplastin time (aPTT) that corrects with a mixing study, a normal prothrombin time (PT), and a normal platelet count. Which of the following is the most likely diagnosis?

Accepted Answer

Hemophilia A

Answer

The clinical presentation of spontaneous hemarthrosis in a male patient, combined with an isolated prolonged aPTT, is classic for Hemophilia A (Factor VIII deficiency) or Hemophilia B (Factor IX deficiency). The aPTT measures the integrity of the intrinsic pathway, which includes Factor VIII. A normal PT and platelet count make DIC and Vitamin K deficiency (which would prolong PT first) less likely. While Von Willebrand disease can sometimes present with a prolonged aPTT due to low Factor VIII levels, it is primarily a disorder of platelet adhesion, typically causing mucocutaneous bleeding rather than deep joint bleeds.

Question 4

A 55-year-old woman is receiving combination chemotherapy for breast cancer. Which of the following agents is most notoriously associated with a dose-dependent, cumulative cardiotoxicity that can lead to congestive heart failure?

Accepted Answer

Doxorubicin

Answer

Doxorubicin, an anthracycline antibiotic, is well-known for causing dose-dependent cardiotoxicity. The risk of developing cardiomyopathy and congestive heart failure increases significantly with higher cumulative doses. Vincristine is associated with peripheral neuropathy, Cisplatin with nephrotoxicity and ototoxicity, and Methotrexate with myelosuppression and mucositis.

Question 5

A pathologist examining a lymph node biopsy from a 24-year-old male with painless cervical lymphadenopathy identifies large, binucleated cells with prominent eosinophilic nucleoli, described as having an 'owl's eye' appearance. These cells are scattered within a background of reactive lymphocytes, eosinophils, and plasma cells. This pathognomonic finding is diagnostic of which malignancy?

Accepted Answer

Classical Hodgkin lymphoma

Answer

The described cell is a classic Reed-Sternberg cell, which is the pathognomonic hallmark of classical Hodgkin lymphoma. The 'owl's eye' appearance is due to its large size, binucleation, and prominent, inclusion-like nucleoli. The presence of these cells within a mixed inflammatory background is essential for the diagnosis.

MD - Doctor of Medicine Practice Test

MD - Doctor of Medicine Practice Test

MD - Doctor of Medicine Hematology and Oncology Questions and Answers