Question 125
A 9-year-old male is brought to the emergency room by his parents because he has been sick for the past five days. He has not passed stool in two days. He has not wanted to eat, and has been vomiting anything his parents are able to get him to eat. Physical examination reveals abdominal tenderness associated with guarding and rebound tenderness. He is diagnosed with a perforation of the terminal ileum, and a resection is performed. Examining the pathologic specimen, the pathologist notes a mass. Genetic analysis of the mass would most likely reveal which of the following?
A. t(8;14)
B. t(2; 8)
C. t(15;17)
D. t(11;14)
E. t(8;21)
F. t(9;22)
G. t(14;18)
Answer for Question 125
Answer: A (t(8;14))
Explanation: The boy has a bowel obstruction. The source of the bowel obstruction is a neoplasm. Given his age and the location, Burkitt lymphoma is very likely. Burkitt lymphoma is associated with MYC (chromosome 8). The most common translocation moves MYC adjacent to the heavy chain gene on chromosome 14; thus, t(8;14). A translocation moving the MYC gene adjacent to one of the light chain genes t(2;8) or t(8;22) is also possible, but less common than t(8;14). While AML can present as a mass, this would be much less common than Burkitt lymphoma in this age group; so t(15;17) and t(8;21) are very unlikely. Mantle cell (t(11;14)) and follicular lymphoma (t(14;18)) are much more common in adults. t(9;22) would be associated with CML or ALL, which would be uncommon causes of a mass lesion, and not frequently associated with gastrointestinal manifestations.
Question 126
A 61-year-old female presents to her family physician with complaints that over the past year she has developed several bumps at places around her body. Her sister died of metastatic breast cancer and she is concerned that the same thing may happen to her. Physical examination reveals palpable lymph nodes on the right side of her neck, both axillae, and her left femoral region. A biopsy of one of the lymph node is performed. The pathologist describes a nodular neoplastic proliferation in the lymph node. The neoplastic cells express CD20 and CD10, but do not express CD5. Of the following, which set of features best describes this neoplasm.
Answer for Question 126
Answer: A (t(14;18) is present and involves BCL-2; t(11;14) is absent)
Explanation: The clinical characteristics of follicular lymphoma include generalized lymphadenopathy at presentation, the disease affects older patients (>50 years of age), and males and females are affected about equally. The staining characteristics in this case (CD20 and CD10 positive, and CD5 negative) are consistent with follicular lymphoma, which has a t(14;18) translocation involving the BCL-2 gene. Mantle cell lymphoma has a t(11;14), which involves the cyclin D1 gene, and mantle cell lymphoma is CD 5 positive.
Question 127
A 37-year-old white female who works at a local factory presents to her family physician complaining that over the past 6 months she has been more tired than normal, and when she exerts herself she will get shorter of breath than normal. A complete blood cell count reveals a hemoglobin of 8.5 g/dL, hematocrit of 24%, white blood cells count of 7200 cells/mm3, and platelet count of 250,000/mm3. Examination of the blood smear reveals red blood cells with increased central pallor. Of the following, what is the most likely diagnosis?
A. Iron deficiency anemia
B. Sarcoidosis with involvement of the bone marrow
C. Aplastic anemia due to chemical exposure at work
D. Acute leukemia
E. Parasitic infection
Answer for Question 127
Answer: A (Iron deficiency anemia)
Explanation: Given the fact that there is anemia without a decrease in any other cell line, the disorder is specific to the red blood cells and not from a generalized process involving the bone marrow, which would likely exclude sarcoidosis and acute leukemia; in addition, an acute leukemia would most likely present quicker (weeks to a few months). Aplastic anemia, such as from a chemical exposure, would affect all cell lines, and she should have thrombocytopenia and leukopenia as well. While a parasitic infection of the blood such as babesiosis or malaria could cause anemia, there is no history of travel or other associated findings to suggest this. Heavy menstrual bleeding would be a relatively common occurrence in younger females, and can lead to iron deficiency anemia.