February 12, 2020 | Pathology Review for USMLE

Questions 143-145: Hematopathology

Question 143

A 63-year-old male with a past medical history of well-controlled hypertension reports to his family physician that over the past 6 months he has had increasing fatigue, weakness, a lack of appetite with a resultant 10 lb. weight loss, and a generalized malaise. A complete blood cell count reveals:

Hemoglobin: 12.2 g/dL
Hematocrit: 36%
White blood cell count: 45 x 103 cells/mm3
Platelet count: 600,000/mm3

The doctor suspects a chronic leukemia, but would like to rule out a leukemoid reaction caused by a smoldering infection. Which of the following laboratory tests would best assist in this distinction?

A. Serum protein electrophoresis
B. Lactate dehydrogenase
C. Leukocyte alkaline phosphatase
D. Repeat the white blood cell count
E. Alanine aminotransferase

Answer for Question 143

Answer: C (Leukocyte alkaline phosphatase)

Explanation: In a leukemoid reaction, the white blood cell count can be markedly elevated, and 45,000 cells/mm3 would be easily possible. In a leukemoid reaction, the white blood cells are functioning normally and an increased amount of leukocyte alkaline phosphatase would be expected; however, in CML the leukocyte alkaline phosphatase is commonly low.

Question 144

A 61-year-old male with a past medical history of well-controlled hypertension and hyperlipidemia reports to his family physician that over the past 12 months he has had increasing fatigue, weakness, and a lack of appetite with a resultant 20 lb. weight loss. A complete blood cell count reveals:

Hemoglobin: 11.8 g/dL
Hematocrit: 38%
White blood cell count: 52 x 103 cells/mm3
Platelet count: 560,000/mm3

Physical examination reveals mild splenomegaly. A peripheral smear would reveal which of the following?

A. An increased number of mature and maturing granulocytes
B. Blasts with a minimal amount of cytoplasm
C. Blasts with a prominent amount of cytoplasm
D. Numerous plasma cells
E. Schistocytes
F. Bite cells
G. Red blood cells with parasites

Answer for Question 144

Answer: A (An increased number of mature and maturing granulocytes)

Explanation: The clinical scenario (an older male) presenting over time with a disease process, with an elevated white blood cell count, elevated platelet count, and mild anemia, and with splenomegaly on the physical examination is consistent with a chronic leukemia. An increased number of mature and maturing granulocytes is consistent with chronic myeloid leukemia. Blasts would be consistent with an acute leukemia, which would present over the course of days to weeks. Numerous plasma cells could indicate multiple myeloma; however, these patients often present with bone pain or signs/symptoms related to hypercalcemia or renal disease.

Question 145

A pathologist is reviewing a blood smear. Numerous red blood cells on the slide have a single peripheral extension from the edge of the cell. Of the following, what is the most likely diagnosis for the patient?

A. Cirrhosis of the liver
B. End-stage kidney disease
C. Myelofibrosis
D. Disseminated intravascular coagulation
E. Hereditary spherocytosis

Answer for Question 145

Answer: C (Myelofibrosis)

Explanation: Red blood cells with a single peripheral extension from the edge of the cell are tear drop cells (i.e., dacrocyte). Tear drop cells are most commonly associated with bone marrow fibrosis. Both burr cells and spur cells (i.e., acanthocytes) have extensions from the periphery of the cell, but the extensions are numerous. Burr cells have regularly distributed extensions and are seen most commonly as artifact; however, they also occur in liver disease and uremia. Spur cells have numerous extensions but they are irregularly distributed. Spur cells are seen in liver disease, abetalipoproteinemia, and McLeod syndrome. Schistocytes have extensions of at least two ends (or, at least two ends of the cell are pointed) and are fragmented. They are associated with DIC. In hereditary spherocytosis, the red blood cells are smaller and contracted with no central pallor.

Questions 140-142: Hematopathology

Question 140

A 54-year-old female with a long-standing history of Sjogren syndrome develops a slowly growing mass in her left submandibular gland. Genetic analysis of the mass is most likely to reveal which of the following translocations?

A. t(8;14)
B. t(9;22)
C. t(11;18)
D. t(12;21)
E. t(15;17)

Answer for Question 140

Answer: C (t(11;18))

Explanation: Patients with autoimmune diseases are at risk for extranodal marginal zone lymphoma, and patients with Sjogren syndrome can develop the lymphoma in a salivary gland. t(11;18) as well as t(14;18) are associated with extranodal marginal zone lymphomas. t(8;14) is associated with Burkitt lymphoma; t(9;22) with CML and ALL; t(12;21) with ALL, and t(15;17) with acute promyelocytic leukemia.

Question 141

Over the past two days, a 13-year-old boy has had one week of diarrhea and abdominal cramping, and then has not passed feces for 2 days. His parents are concerned and have brought him to the emergency room for evaluation. A CT scan of the abdomen reveals a mass at the ileocecal junction and a distended small intestine. Resection of the mass reveals a monomorphous population of large cells with interspersed macrophages containing cellular debris. Of the following, which would genetic analysis of the tumor cells reveal?

A. t(8;14)
B. t(9;22)
C. t(11;14)
D. t(14;18)
E. t(15;17)

Answer for Question 141

Answer: A (t(8;14))

Explanation: The clinical scenario is consistent with Burkitt lymphoma, which most often occurs in children and young adults, and is often found at the ileocecal junction and can cause a bowel obstruction. The histologic description is consistent with Burkitt lymphoma, with the interspersed macrophages containing cellular debris representing the characteristic starry sky pattern. t(8;14) as well as t(2;8) and t(8;22) are associated with Burkitt lymphoma. The MYC protooncogene is on chromosome 8 and the Ig heavy chain gene is on 14, resulting in increased production of MYC.

Question 142

A 57-year-old male with a past medical history of type II diabetes reports to his family physician that over the past 6 months he has felt increasingly tired and unable to complete tasks at work or at home without resting. Occasionally, he has had a fever. He has also lost 15 lbs., which he knows is good for his diabetes. A complete blood cell count reveals:

Hemoglobin: 12.2 g/dL
Hematocrit: 36%
White blood cell count: 45 x 103 cells/mm3
Platelet count: 600,000/mm3

A physical examination reveals an enlarged spleen. Genetic analysis reveals a t(9;22). Of the following, what is the most likely diagnosis?

A. Acute lymphoblastic leukemia
B. Chronic lymphoblastic leukemia
C. Acute myelogenous leukemia
D. Chronic myeloid leukemia

Answer for Question 142

Answer: D (Chronic myeloid leukemia)

Explanation: Given the slow development of symptoms (i.e., their insidious nature), an acute leukemia is not very likely, as these present acutely over days to weeks, and usually not months. While the demographics are consistent with both CLL and CML, as is the splenomegaly, the t(9;22) is found in CML. t(9;22) is also found in adult ALL; however, given the slow development of the symptoms, an acute process is not likely; also, acute leukemia tends to present with pancytopenia, whereas this patient has an elevated platelet count as can be found in CML.

Questions 137-139: Hematopathology

Question 137

During a routine appointment, a 60-year-old man’s dentist palpates some lymph nodes on the right side of the neck. A follow-up physical with a family practitioner reveals additional lymph nodes in the right axilla and the left femoral region. The lymph nodes are painless but rubbery to palpation. Biopsy of the lymph nodes is most likely to reveal which of the following?

A. A starry sky pattern
B. Reed-Sternberg cells
C. Granulomas
D. Nodular effacement of the architecture
E. Metastatic glioblastoma multiforme

Answer for Question 137

Answer: D (Nodular effacement of the architecture)

Explanation: The clinical presentation (painless enlargement of lymph nodes in non-contiguous locations) is consistent with non-Hodgkin lymphoma. Nodular effacement of the architecture describes follicular lymphoma, which is a common non-Hodgkin lymphoma in older patients. A starry sky pattern is characteristic of Burkitt lymphoma, which normally presents in a younger population. Reed-Sternberg cells are characteristic of Hodgkin lymphoma, which involves contiguous groups of lymph nodes. CNS tumors very rarely metastasize. The history does not support a granulomatous process, such as tuberculosis or a non-typical infection, and sarcoid just involving a group of lymph nodes without additional organ involvement would be unlikely.

Question 138

During a yearly physical examination, the primary care physician for a 60-year-old man palpates lymph nodes on both sides of the neck and in the right femoral region. A subsequent biopsy of the lymph nodes is most likely to reveal a nodular effacement of the architecture. Genetic testing would reveal which of the following?

A. t(8;14)
B. t(8;21)
C. t(9;22)
D. t(14;18)
E. t(12;21)
F. t(15;17)

Answer for Question 138

Answer: D (t(14;18))

Explanation: The involvement of non-contiguous lymph nodes is consistent with a non-Hodgkin lymphoma. Nodular effacement of the architecture is a description that is consistent with a follicular lymphoma, which involves older adults. Follicular lymphoma is associated with a t(14;18), which moves the bcl-2 gene adjacent to the Ig heavy chain gene. t(8;14) is associated with Burkitt lymphoma; t(8;21) and t(15;17) with acute myeloid leukemia; t(9;22) with CML and ALL; and t(12;21) with ALL.

Question 139

A 61-year-old male for the past year has had multiple infections, including two episodes of pneumonia and two abscesses in the skin requiring drainage. Prior to that, he had been very healthy, only requiring treatment for hypertension that developed 5 years ago. A physical examination reveals palpable lymph nodes in the left femoral region and right axilla. Of the following, which test is likely to disclose the cause for his repeated infections?

A. Serum ferritin
B. Serum protein electrophoresis
C. CT scan of the chest to assess the thymus
D. EKG
E. Thyroid function testing

Answer for Question 139

Answer: B (Serum protein electrophoresis)

Explanation: The finding of enlarged lymph nodes in non-contiguous locations is consistent with a non-Hodgkin lymphoma. Non-Hodgkin lymphoma of certain types (e.g., SLL) can be associated with a hypogammaglobulinemia. Patients with a hypogammaglobulinemia can be at risk for serious bacterial infections. A serum protein electrophoresis or a urine protein electrophoresis can identify a hypogammaglobulinemia.