Case Study 42Henry Armah, M.D., M.Phil.

Question 1Clinical history: 80-year-old male with past medical history of malignant non-Hodgkin’s lymphoma, diffuse large B-cell type, of the left flank soft tissue and abdominal wall post chemotherapy 10 months prior. He also had past medical history significant for status post pacemaker placement, colorectal carcinoma, aortic valve replacement, diabetes mellitus, chronic obstructive pulmonary disease and coronary artery disease. He presented with confusion and unsteady gait. MRI was not done because the patient had a pacemaker. Describe the abnormal findings of this cranial CT scan with contrast?

Ax CT+C

AnswerBilateral thalamic and mesial temporal contrast enhancing masses.

Question 2What are your differential diagnoses based on the patients’ age, past medical history, and the radiological findings?

Answer1. Malignant Lymphoma

2. High-grade Glioma

3. Metastatic carcinoma

4. Abscess

Question 3The neurosurgeon performs a CT-guided stereotactic biopsy of the mass, and requested an intraoperative consultation. Describe the microscopic findings on this touch preparation slide?

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AnswerBlood and scattered atypical cells.

Question 4

What is your intraoperative diagnosis? (A: Category such as Defer, Reactive/Non-neoplastic, or Neoplastic; B: More specific diagnosis or statement)

AnswerA. Defer

B. Atypical cells with hemorrhage

Question 5The permanent section has returned from histology. Describe the microscopic findings on this H&E slide?

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AnswerFragments of brain tissue extensively and diffusely infiltrated by angiocentric dense atypical lymphoid infiltrates. The majority of the lymphoid cells are large with moderate pleomorphism and occasional mitosis. The interface between the diffuse lymphoid infiltrate and the adjacent brain parenchyma show reactive gliosis.

Question 6What additional studies would you need to confirm the final diagnosis in this case?

Answer1. CD20 (L26)

2. CD5

3. CD10

4. BCL-2

5. MUM-1

6. Ki-67 (MIB-1)

7. CD3

8. Cyclin D1

9. CD21

10.EBER (EBV Insitu Hybridization)

Question 7What do you see on this CD20 (L26) immunostain slide?

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AnswerCD20 (L26) is strongly and diffusely positive in the neoplastic lymphoid cells.

Question 8What do you see on this CD5 immunostain slide?

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AnswerCD5 is strongly and diffusely positive in the neoplastic lymphoid cells.

Question 9What do you see on this CD10 immunostain slide?

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AnswerCD10 is strongly and diffusely positive in the neoplastic lymphoid cells.

Question 10What do you see on this BCL-2 immunostain slide?

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AnswerBCL-2 is strongly and diffusely positive in tumor cells.

Question 11What do you see on this MUM-1 immunostain slide?

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AnswerMUM-1 is strongly and diffusely positive in tumor cells.

Question 12What do you see on this Ki-67 (MIB-1) immunostain slide?

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AnswerKi-67 (MIB-1) is positive in the nuclei of greater than 90% of the neoplastic lymphoid cells.

Question 13What do you see on this CD3 immunostain slide?

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AnswerCD3 is negative in the neoplastic lymphoid cells, but highlights scattered reactive T-lymphocytes at the interface between the lesion and the adjacent brain parenchyma.

Question 14What do you see on this Cyclin D1 immunostain slide?

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AnswerCyclin D1 is negative in the neoplastic lymphoid cells, but highlights rare admixed lesional cells most probably infiltrating reactive lymphocytes.

Question 15What do you see on this CD21 immunostain slide?

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AnswerCD21 is negative in the neoplastic lymphoid cells.

Question 16What do you see on this EBER (EBV Insitu Hybridization) slide?

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AnswerEBER (EBV Insitu Hybridization) is negative in the neoplastic lymphoid cells.

Question 13What is your final diagnosis in this case?

AnswerMalignant Non-Hodgkin’s Lymphoma, Diffuse Large B-Cell Type