Morphology week summary.
Our followers were correct in suggesting these were plasma cells, one of which is binucleate on the second picture. Thrombocytopenia was also noted. This would be in keeping with a diagnosis of plasma cell leukaemia. Immediate investigations would include:
- CRAB features – hypercalcaemia, renal dysfunction, anaemia, bone involvement
- Serum electrophoresis, paraprotein screen and serum free light chains
- Peripheral blood could be sent for flow cytotmetry to confirm diagnosis
- Bone marrow aspirate+trephine +/- flow and cytogenetic
Blood film features: abnormal pleomorphic lymphocytes with condensed nuclear chromatin, irregular nuclear outlines, basophilic cytoplasm, irregularities of cytoplasm margin, some villous projections seen, occasional larger cells with prominent nucleoli. Thrombocytopenia.
The majority of followers picked up that this was a proposed lymphoproliferative disease with the most common differential being mantle cell or CLL
Flow cytometry :
Cyclin D1 expression (11:14)(q13:32)negative
The flow results gives a CLL score of 1/5, making CLL an unlikely diagnosis. Mantle cell is also less likely given the negative cyclin D1 expression, although it could be atypical mantle cell. SOX11 positivity would help confirm this diagnosis. The diagnosis in this case was actually splenic marginal zone lymphoma. The patient had splenomegaly and no lymphadenopathy on exam. CD5 expression is well recognised in SMZL, and has no pathological difference from CD5- cases, except a higher white cell count at presentation. Thrombocytopenia is a common finding in SMZL and may be due to a number of causes, including splenic sequestration of platelets, reduced production due to marrow infiltration or immune-mediated phenomena.
Case C and D
These cases also looked at patients with a clonal lymphoid population, testing our morphology skills when trying to determine a more definitive diagnosis.
The blood film shows small to medium sized lymphocytes, which have a uniform appearance. There is scanty cytoplasm which has a regular border. The nuclear:cytoplasmic ratio is high. The nucleus has a regular border and condensed chromatin. Smear cells can also be seen although not noted in this part of the film. Of note this film also shows a myelocytes (top of the film), red cells are macrocytic and platelet numbers are low.
Result 1 from the flow cytometry was correct with the diagnosis of CLL with a CLL score of
CD 23 ++
This blood film shows medium sized lymphocytes with non-condensed chromatin with a cleaved irregular nucleus outline. This film also demonstrated thrombocytopenia.
Result 2 – suggested that the diagnosis in this case was that of mantle cell lymphoma which would fit with the morphology.
CD 23 –
cyclin D1 positive
Cases B to D were a test of our morphology skills. Although we now often have the luxury of flow cytometry to determine the final diagnosis, it is always useful to have a provisional diagnosis in mind following film review. The table below may help with reviewing flow cytometry
The following table helps when assessing morphology
The final case was a patient that had presented with a vasculitis and a diagnosis of cryoglobulinaemia was pick on blood film review. The film shows cryoglobulin deposits indicated by the arrow. Multiple deposits were found throughout the film.
1. Dacie and Lewis Practical Haematology. BJ.Bain, I.Bates, M.A.Laffan. 12th edition.
2. The Hematologist. Diagnostic approach to lymphocytosis. American Society of hematology. November to December 2015, volume 12 issue 6.