Lymph node and spleen

Question 1

Lymph node effaced by nodules of mixed inflammation divided by broad fibrous bands, with lacunar cells (Reed–Sternberg cells suspended in a retracted space or halo).

Answer 1

Classical Hodgkin’s lymphoma (nodular sclerosing type)

Differential diagnosis:
Nodular lymphocyte predominant Hodgkin lymphoma

Plan:
Correlate with clinical history and radiology
IPX to support Dx: CD30 and 15, CD20 and 45, PAX5, CD3, EBER (expect positivity with CD30 and 15 with weak PAX5 positivity, nodular lymphocyte predominant would be CD30/15 negative, CD230 and 45 positive)
Next steps: Discuss at MDT

Question 2

Bone lesion with clusters, nodules or sheets of plasma cells which may be atypical

Answer 2

Plasma cell myeloma

Differential diagnosis:
Solitary plasmacytoma of bone
Lymphoplasmacytic lymphoma
Reactive plasmacytosis

Plan:
Correlate with clinical history and radiology (?hypercalcaemia ?renal impairment ?anaemia ?presence of multiple lytic bone lesions ?serum/urine monoclonal protein ?bone marrow trephine findings)
IPX to support Dx: CD138, CD38, kappa and lambda light chains (expect positive, with light chain restriction)
IPX to discount DDx: CD20, PAX5 (for lymphoma).
Next steps: Synoptic report, discuss at MDT

Question 3

Lymph node effaced by a nodular proliferation of back to back follicles, which contain a mixture of centrocytes (small lymphocytes with cleaved nuclei) and centroblasts (larger with vesicular chromatin and nucleoli). Follicles lack tingible body macrophages.

Answer 3

Follicular lymphoma

Differential diagnosis:
Mantle cell lymphoma
Marginal zone lymphoma
Reactive follicular hyperplasia

Plan:
Correlate with clinical history and radiology (?lymphadenopathy ? involvement of other organs ?blood counts)
Correlate with concurrent flow cytometry findings
Examine further sections (e.g. for pattern of involvement, presence of diffuse growth, grade)
IPX to support Dx: CD20, CD10, BCL2, BCL6 (expect positive). CD23 (may show disrupted FDC meshwork)
IPX to discount DDx: Cyclin D1, CD5 (mantle cell lymphoma), CD45 (marginal zone lymphoma),
Molecular: PCR or FISH for IGH-BCL-2 translocation
Next steps: Synoptic report, discuss at MDT

Question 4

Lymph node effacted by a diffuse, homogenous population of small lymphocytes with round, regular nuclei with ‘soccer ball’ clumped chromatin. May have vague pseudofollicles (proliferation centres) containing slightly larger prolymphocytes.

Answer 4

Small cell lymphoma / chronic lymphocytic leukemia

Differential diagnosis:
Mantle cell lymphoma
Marginal zone lymphoma
Follicular lymphoma

Plan:
Correlate with clinical history and blood tests (?circulating lymphocytosis)
Correlate with concurrent flow cytometry findings
IPX to support Dx: CD20 and PAX5, CD5, CD23 (expect positive)
IPX to discount DDx: Cyclin D1, CD10, BCL6, BCL2, CD43
Next steps: Synoptic report, discuss at MDT.

Question 5

Lymph node with large suppurative (containing neutrophils) necrotising ‘stellate’ granulomas

Answer 5

Cat-scratch disease (Bartonella henselae)

Differential diagnosis:
Other infectious agents (e.g. TB, and atypical mycobacteria, fungi, tularemia, syphilis)
Kikuchi lymphadenitis

Plan:
Correlate with clinical history and radiology (?cat exposure ?distribution of lymphadenopathy)
Correlate with concurrent microbiologic testing - if not done, parrafin block can be used for PCR
Special stains: Warthin-Starry (may highlight organisms). Also gram stain, PAS and GMS, ZN and modified ZN (Wade-Fite) - to look for other organisms.
IPX to support Dx: B. henselae

Question 6

Lymph node effaced by sheets of large cells with pleomorphic nuclei with vesicular chromatin and prominent nucleoli.

Answer 6

Diffuse large B cell lymphoma

Differential diagnosis:
Metastatic melanoma
Metastatic poorly differentiated carcinoma
Other specifically defined lymphomas:
-Burkitt lymphoma
-High-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements (“double-hit” or “triple-hit” lymphoma)
-EBV, ALK, or HHV8 positive DLBCL
-Grade 3 follicular lymphoma, blastoid mantle cell lymphoma
-Large B cell lymphomas defined by organ (e.g. primary mediastinal)
-T cell lymphomas

Plan:
Correlate with clinical history and radiology (?site /distribution of disease ?previous lymphoma Dx)
Correlate with concurrent flow cytometry
IPX to support Dx:
CD20, PAX5 (confirm B cell)
CD10, MUM1, BCL6 (Hans Algorithm)
BCL2, MYC (possible rearrangements)
Ki67
IPX to discount DDx:
S100, SOX10, Melan A
AE1/AE3, CAM5.2
EBER, ALK, HHV8
CD21, CD23 (preserved dendritic meshwork in FL)
CD5 and cyclin D1 (blastoid mantle cell lymphoma)
CD3 (T cell lymphomas)
Molecular: FISH for BCL2, BCL6, MYC rearrangements
Next steps: Synoptic report, discuss at MDT

Question 7

Stomach, salivary gland, or thyroid infiltrated with monocytoid lymphocytes (with a rim of pale cytoplasm) and plasma cells, with frequent infiltration of lymphocytes into epithelium (lymphoepithelial lesion)

Answer 7

MALT lymphoma

Differential diagnosis:
Reactive lymphoid hyperplasia (e.g. chronic gastritis, sialadenitis, lymphocytic thyroiditis)
Other mature B cell lymphomas: Follicular, mantle cell, SLL/CLL

Plan:
Correlate with clinical history and radiology (?H pylori in stomach ?Hashimoto in thyroid ?Sjogren’s in salivary gland)
IPX to support Dx: CD20 and PAX5, BCL2, CD43 (may be positive)
IPX to discount DDx: CD23 (SLL), cyclin D1 (mantle cell), CD5 (both), CD10 and BCL6 (follicular)
Next steps: Synoptic report, discuss at MDT

Question 8

Lymph node with increased vascularity between follicles, with individual follicles having expanded mantle zone with concentrically arranged lymphocytes (‘onion skin’) and atrophic germinal centre replaced with hyalinization / hyalinized blood vessels. Germinal centres of adjacent follicles may fuse ‘twinning’ and a blood vessel traversing the mantle into the hyalinized germinal centre may create a ‘lollipop’ sign.

Answer 8

Castleman’s disease (hyaline vascular type)

Plan:
Correlate with clinical history and radiology (?lymphadenopathy ?immunosupression ?unicentric or multicentric)
Correlate with concurrent flow cytometry findings
IPX: Not required (morphologic diagnosis)

Question 9

Lymph node containing a tumour of bland spindle cells arranged in short fascicles with nuclear pallisading, surrounded by hypocellular areas containing collagen bundles (so-called amianthoid fibers), often with extravasated red blood cells and hemosiderin deposition.

Answer 9

Intranodal palisaded myofibroblastoma

Differential diagnosis: Schwannoma

Plan:
Correlate with clinical history and radiology
IPX to discount DDx: S100
No further action required for this benign diagnosis

Question 10

Name of collagen bundles in intranodal palisaded myofibroblastoma?

Answer 10

Amianthoid fibres

Question 11

Spleen with well demarcated, unencapsulated nodule composed of anastomosing vascular channels lined by plump, cuboidal to tall endothelial cells which may form papillae or tufts projecting into the lumen and frequently contain hemosiderin pigment.

Answer 11

Littoral cell angioma of spleen

Plan:
Correlate with clinical history and radiology (?assiociated malignancy or autoimmune disease)
Examine further blocks (e.g. for size, relation to margins)
IPX to support Dx: CD34, CD31, CD68 (expect CD34 negative, CD31 and CD68 positive)
Advice to clinician: Benign, but may be assiociated with a variety of malignancies and autoimmune conditions. Clinical correlation is required.