Quick Facts

Question 1

Marginal zone markers

Answer 1

CD43, Lef1, CD5

Question 2

Mantle cell markers

Answer 2

Cyclin D1, Lef1, CD5, SOX11

Question 3

Lef1 in hematopathology

Answer 3

Almost always positive in CLL/SLL

Can be positive in most small B cell lymphomas (SLL, mantle cell, marginal zone)

Question 4

TFH markers in hematopathology

Answer 4

ICOS
PD1
BCL6
CD10
CXCL13

Question 5

Two times to consider gray zone lymphoma

Answer 5

1. Too many Hodgkinoid cells with Hodgkinoid immunophenotype (loss of pan-B-cell program markers)
2. Hodgkinoid distribution of neoplastic B cells, but pan-B-cell program markers are maintained.

Question 6

Answer 6

Acute myelomonocytic leukemia

Abundant, gray-blue cytoplasm with vacuoles

Question 7

Answer 7

Pseudo-gaucher cells

Histiocytes with rounded, blue, lamellar cytoplasm resembling “onion skin” that can be found in up to 40% of the bone marrow of patients with CML, but may occur more rarely in other leukemias as well.

Question 8

Most common post-transplant NK/T cell LPD

Answer 8

Hepatosplenic T-cell lymphoma

Question 9

What percentage of post-transplant LPD is NK/T cell in type?

What percentage of NK/T cell PTLD is associated with EBV?

Answer 9

15% of PTLD is NK/T cell in type.

Only 1/3 of NK/T cell PTLD is EBV associated (while most B cell PTLD is EBV associated).

Question 10

ATLL immunophenotype

Answer 10

A CD3 positive, CD5 positive, CD7 negative, CD4 positive, CD8 negative, and CD25 positive phenotype is characteristic of ATLL.

Question 11

What is the most common site for extramedullary plasmacytoma?

Answer 11

The upper respiratory tract

80% of extramedullary plasmacytomas occur here

Question 12

Most common disorder of the erythroid glycolytic pathway

Answer 12

Pyruvate kinase deficiency

Accounts for 90% of cases

Question 13

Most common disorder of the erythroid pentose phosphate pathway

Answer 13

G6PD deficiency

Question 14

What lymphoma likes to involve the bone marrow as paratrabecular infiltrates?

Answer 14

Follicular lymphoma

Question 15

MDS with del5q mostly affects

Answer 15

Middle aged to older women

Question 16

Some believe that progressive transformation of germinal centers is a precursor lesion to. . .

Answer 16

. . . NLPHL

Since they are often found in the same lymph node.

Question 17

Mutations in which gene are associated with adverse prognosis in AML with normal karyotype?

Answer 17

FLT3

Especially in the context of NPM1 mutated AML

Question 18

Basophilic stippling represents. . .

Answer 18

precipitated ribosomal RNA

Basophilic stippling can be seen in thalassemias, myelodysplastic neoplasms, and lead poisoning.

Question 19

Therapy-related myeloid neoplasia in association with aklylating agents tends to present as. . .

Answer 19

MDS with cytogenetic abnormalities seen in de novo MDS

Question 20

Therapy-related myeloid neoplasia in association with topoisomerase inhibitors tends to present as. . .

Answer 20

MDS or AML with 11q23 or MLL gene abnormalities

Question 21

Extranodal marginal zone lymphoma involving the lacrimal gland or orbit is associated with which bacteria?

Answer 21

Chlamydia psittaci

Question 22

Answer 22

Parvovirus B19 inclusions

They are lightly basophilic and smudy compared to the background chromatin in erythroblasts, as seen here.

Question 23

Effects of lithium on bone marrow

Answer 23

Lithium can drive a myeloid hyperplasia with maturation

Question 24

ALK prognostication in ALCL

Answer 24

ALCL cases associated with t(2;5) translocation and ALK protein overexpression (ALCL, ALK-positive) are generally associated with a more favorable prognosis compared to ALK-negative ALCL. ALK-positive ALCL tends to be seen in pediatric and young adults, whereas the ALK-negative ALCL tends to occur in adults.

Question 25

Most cases of ALCL also express. . .

Answer 25

. . . cytotoxicity markers

Granzyme B, perforin, TIA-1

Question 26

Answer 26

Toxoplasmal pseudocyst