Ch. 25 - B-cell lymphoma and lymphocytic leukemia

Question 1

How do cutaneous B-cell neoplasms compare to nodal B-cell neoplasms?

Answer 1

Generally have a better prognosis.

Question 2

Primary cutaneous marginal zone lymphoma

Question 3

Primary cutaneous follicle center cel lymphoma

Answer 3

Follicles with reduced or absent mantle zones and tingible body macrophages. Lack of polarity. CD20+, CD79+, BCL2-, BCL6+. t(14;18) is uncommon in cutaneous.

Question 4

Distinguish between nodal and primary cutaneous follicle center cell lymphomas.

Answer 4

In primary cutaneous, BCL2 expression is rare. Positivity suggests a nodal primary with secondary skin involvement.

Question 5

Cutaneous diffuse large B-cell lymphoma, leg type

Answer 5

Dense diffuse infiltrate of large round immunoblast-type cells with prominent nucleoli and no centrocytes. CD20+, CD79a+, BCL2+, MUM1+.

Question 6

Cutaneous diffuse large B-cell lymphoma, other than leg-type

Answer 6

Monomorphous population of centroblast-like cells with benign mixed background. Usually BCL6+.

Question 7

Intravascular large B-cell lymphoma

Answer 7

Partial occlusion of vessels by large round tumor cells (hobnailing) and fibrin. CD20+, CD79a+. Can produce neurologic deficits! Aggressive.

Question 8

Lymphomatoid granulomatosis

Answer 8

EBV-associated angiocentric infiltrate. May have granulomatous inflammation.

Question 9

CLL/SLL

Answer 9

Mature round monotonous lymphocytes in dermis often with Grenz zone. May have prolymphocytes. CD5+, CD19+, CD20 (weak), CD23/43+, CD10/D1-.

Question 10

Mantle cell lymphoma

Answer 10

Usually nodal-primary. Intermediate-sized lymphocytes with irregular nuclei. CD5+, CD20+, BCL2+, CD23-. t(11;14)/CyclinD1 overexpression.

Question 11

Burkitt lymphoma

Answer 11

Usually not cutaneous primary. “Starry-sky” diffuse growth with macrophages phagoctizing necrotic tumor. CD19/20+, CD79a+, MIB-1 100%.

Question 12

B-cell lymphoblastic lymphoma/leukemia

Answer 12

Lymphoblasts slightly larger than mature lymphocytes with inconscpicuous nucleoli and scant cytoplasm. Starry-sky tingible pattern. TdT+, CD34+, CD79a+.

Question 13

Answer 13

Primary cutaneous marginal zone lymphoma

Question 14

Answer 14

Primary cutaneous follicle center cell lymphoma

Question 15

Answer 15

Cutaneous DLBCL, leg type

Question 16

Answer 16

Cutaneous DLBCL, other than leg type

Question 17

Answer 17

Intravascular large B-cell lymphoma

Question 18

Answer 18

CLL/SLL