Skip to main content

Low grade lymphoma

(This is another final part of the Sabah lymphoma talk: Part One, Two, Three.)

I. Marginal zone B cell lymphoma

  • Types: Nodal, extranodal, splenic.
  • Immunohistochemically different from mantle cell lymphoma, follicular lymphoma, and small lymphocytic lymphoma.
  • Differential diagnosis: Reactive monocytoid B-cell hyperplasia.
  • Patterns:
    • Diffuse pattern: diffuse sheets of neoplastic cells with effacement of nodal architecture.
    • Nodular pattern: distinct nodules, well-demarcated.
    • Interfollicular pattern: neoplastic cells in interfollicular areas that surround residual germinal centres.
    • Perifollicular pattern: annular distribution of neoplastic cells around the uninvolved normal secondary follicles.
  • Histology:
    • Vague nodules with sclerosed blood vessels.
    • Stromal sclerosis which compartmentalize the small groups of neoplastic cells.
    • Monocytoid / plasmacytoid cells, singly distributed or in clusters.
    • Increased large cells with nuclear pleomorphism (not seen in mantle cell lymphoma)
  • Immunohistochemistry:
    • CD20 and CD43 positive.
    • Weakly positive CD23.
    • Negative for CD5.
    • Follicular dendritic cells are distrupted with presence of interfollicular nests.
    • Low Ki-67.
II. Follicular lymphoma
  • Composed of centrocytes and centroblasts.
  • Must have at least a focal follicular pattern.
  • Follicles are crowded; may have presence of mantle zone with lack of polarization.
  • Germinal centre type with positivity for BCL-2 (85%)/
  • May have interfollicular CD10-positive cells.
  • Immunohistochemistry: Positive for CD10, BCL-6 and BCL-2
    • BCL-2 is positive in all low-grade lymphomas.
  • Variants:
    1. Paediatric
    2. Primary intestinal
    3. Extranodal
    4. Follicular lymphoma in situ (interfollicular)
  • Follicular lymphoma post Rituximab treatment:
    • CD20 negative, CD79a positive.
    • Must use more than one antibody marker.
III. Mantle cell lymphoma
  • Usually small or medium-sized.
  • Slightly irregular or cleaved nuclei.
  • Spectrum: lymphocyte-like, large cleaved, or lymphoblast-like.
  • Centroblasts and immunoblasts are rare.
  • CD5 and Cyclin D1 positive
  • Diagnostic pitfall: mantle cell lymphoma with features of marginal zone lymphoma.
IV. Small lymphocytic lymphoma (SLL)
  • Diffuse or vague nodular patter (due to proliferation center)
  • May have plasmacytoid differentiation.
  • 10% of cases may have Richter's transformation.
  • Immunohistochemistry: weak CD20 positivity, positive for CD5, CD3 and CD43.  Negative for BCL-6 and Cyclin D1.
V. Lymphoplasmacytic lymphoma
  • Also known as immunocytoma.
  • Diffuse infiltrate of LP cells and plasma cells with intrasinusoidal pattern.
  • Now considered as marginal zone lymphoma (immunohistochemistry is the same as marginal zone lymphoma)

Labels

Labels:

Comments

Post a Comment

Popular posts from this blog

8 L's and DRUGS

I am so happy that I found an educational gem by Sullivan Nicolaides Pathology , a private pathology lab in Australia.  There are some videos of live lectures that one can find here.  I am particularly excited (and maybe starstruck) to find Professor  David Weedon's lectures here -- as I am particularly fond for Dermatopathology. A particular thing I learned today from Professor David Weedon was a checklist mnemonic for perivascular infiltrate in the skin: 8L's and DRUGS Light reaction Lymphoma (and pseudo) Leprosy Lues Lichen striatus Lupus erythematosus Lipoidica (and incomplete granuloma annulare) Lepidoptera (arthropods etc) Dermatophyte Reticular erthymatous mucinosis Urticaria Gyrate erythema Scleroderma
Post a Comment
Read more

Reactive Conditions of the Lymph Node

(This is a continuation of the notes I have taken from the Sabah Lymphoma talk ) I. Lymphadenopathies Lymphadenopathies are divided into three: 1. Reactive lymphoid hyperplasia 2. Atypical lymphoid hyperplasia 3. Progressive transformation of germinal centre 1. Reactive lymphoid hyperplasia Has a follicular pattern OR may present as diffuse paracortical hyperplasia. Characteristics: architecture preserved, capsule intact, enlarged germinal centre, mitotically active, tingible body macrophages, mantle zone present . Main differential of follicular pattern: follicular lymphoma. 2.  Progressive transformation of germinal centre Mainly in adolescent males. Numerous follicules in different stages with follicular hyperplasia. Late stage: small lymphocytes infiltrating germinal centres, germinal centre disrupted. II. Castleman's disease 1.  Hyaline vascular variant Can be unilocular or multiple places. Numerous follicles with small germinal centre, on...
1 comment
Read more

Autopsy exam

Autopsy exam is a necessity for a trainee anatomic pathologist to pass the final exam, but it is quite a pain to study for it.  I found some brief notes (and possible exam questions) to survive the exam. Assessment: History Gross findings Dissect all organs Make sure dissection area is clean. Cause of death and correlation. How does one diagnose pneumothorax on autopsy? Dissect out the circle of Willis. How to measure ventricular thickness. Answer: 1 cm below the atrioventricular valve How to differentiate between kidney abscess and pyonephrosis. Kidney abscess is usually located at the renal cortex. How to take swabs (from any sites) How to take blood samples. Answer: from femoral vein or right atrium. How to take urine sample. Answer: suprapubic Spleen may also show hyaline arteriosclerosis, like kidneys (hypertensive change). Renal papillary necrosis is common in diabetes mellitus. ARDS (adult respiratory distress syndrome) is a manifestation of ...
Post a Comment
Read more