Hematology PB Smears and Plasma Cells

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Questions and Answers

What is the most striking feature observed on PB smears?

High white blood cell count

Presence of blast cells

Rouleaux formation (correct)

Leucoerythroblastic picture

Rouleaux formation is related to which of the following?

Severity of anemia

Increased platelet count

Number of lymphocytes

Quantity and type of M protein (correct)

Which picture may be observed in some cases along with Rouleaux formation?

Hemolytic anemia picture

Leucoerythroblastic picture (correct)

Granulocytic picture

Thrombocytopenic picture

Which factor is NOT typically associated with Rouleaux formation?

Lack of white blood cells Signup and view all the answers

What does Rouleaux formation indicate about the blood's composition?

Abnormal aggregation of red blood cells Signup and view all the answers

What can be said about the variation of plasma cells in the observed cases?

They fluctuate with a range from almost unchanged to over 90%. Signup and view all the answers

What is the upper limit of plasma cell variation reported?

90% Signup and view all the answers

What is the minimum change reported for plasma cells?

Barely increased. Signup and view all the answers

What is observed in trephine biopsy sections in certain instances?

More PCs Signup and view all the answers

In which month was the update regarding plasma cells reported?

November Signup and view all the answers

Which feature may be present alongside increased PCs in trephine biopsy sections?

Focal clusters or nodular aggregates Signup and view all the answers

What is implied about the consistency of plasma cell increase across cases?

It shows significant variability. Signup and view all the answers

What types of arrangements of PCs might be evident in trephine biopsy sections?

Focal clusters or sheets of PCs Signup and view all the answers

Besides PCs, which of the following is NOT mentioned as potentially being observed in trephine biopsy sections?

Necrotic tissue Signup and view all the answers

Which of the following correctly describes the plasma cell distribution possible in trephine biopsy sections?

More concentrated with focal clusters or sheets Signup and view all the answers

What does a bone marrow trephine biopsy indicate?

Infiltration by clusters of plasma cells Signup and view all the answers

What characteristic is seen in some plasma cells according to the biopsy results?

Increased size with cytologic atypia Signup and view all the answers

Which type of infiltration is indicated by the biopsy findings?

Diffuse and massive infiltration by plasma cells Signup and view all the answers

What does the presence of clusters of plasma cells in the biopsy suggest?

Possibility of malignancy Signup and view all the answers

What type of cells shows cytological atypia in the bone marrow biopsy?

Plasma cells Signup and view all the answers

What is an important use of MRI imaging in clinical assessment?

Assessing extramedullary disease Signup and view all the answers

In which scenario would MRI imaging be particularly beneficial?

Assessing suspected cord compression Signup and view all the answers

When is detailed imaging of a symptomatic area necessary using MRI?

When extramedullary disease is suspected Signup and view all the answers

What condition can MRI help assess that involves the spinal cord?

Cord compression Signup and view all the answers

Which of the following is NOT a reason to utilize MRI imaging?

Capturing standard x-ray images Signup and view all the answers

What primarily defines a phenotypically aberrant plasma cell population?

Presence of CD56 and lack of CD19 Signup and view all the answers

Which marker is used to confirm the clonal plasma cell population?

Light chain restriction Signup and view all the answers

What does the presence of normal residual plasma cells indicate?

Normal hematological function Signup and view all the answers

What color represents the phenotypically aberrant plasma cell population in the description?

Red Signup and view all the answers

Which statement accurately describes the distinction between aberrant and normal plasma cells?

Aberrant plasma cells are CD19 negative and CD56 positive. Signup and view all the answers

Study Notes

Multiple Myeloma - 2024 Update

Multiple myeloma is a clonal plasma cell disorder, characterized by an abnormal increase in monoclonal immunoglobulins.
It accounts for 1% of all cancers and approximately 10% of hematological malignancies.
Slightly more common in men than women, and twice as common in African-Americans compared to Caucasians.
Median age at diagnosis is approximately 65 years.

Disease Overview

Unlike other malignancies that metastasize to bone, osteolytic lesions in MM don't exhibit new bone formation. Bone disease is the primary cause of morbidity.
Other major clinical manifestations include anemia, hypercalcemia, renal failure, and an increased risk of infections.
Extramedullary disease (EMD) occurs in approximately 1-2% of patients at initial diagnosis, and 8% develop EMD later.

Symptoms of Multiple Myeloma

Hypercalcemia
Renal dysfunction
Anemia
Bone pain

Monoclonal Gammopathy of Undetermined Significance (MGUS)

Almost all myeloma patients originate from MGUS, a pre-malignant, asymptomatic stage.
MGUS occurs in approximately 5% of the population over 50, and is two-fold higher in blacks versus whites.
MGUS progresses to multiple myeloma at a rate of 1% per year. Over half of those diagnosed with MGUS have had the condition for more than 10 years before clinical diagnosis.
An intermediate stage, called smoldering multiple myeloma (SMM), can exist between MGUS and active myeloma.

Smoldering Multiple Myeloma (SMM)

SMM is prevalent in approximately 0.5% of the general population aged 40 or older.
It progresses to multiple myeloma at an approximate rate of 10% in the first 5 years after diagnosis, then 3% in the next 5 years, and 1.5% per year thereafter.
Cytogenetic abnormalities (e.g., t(4;14), del(17p), gain(1q)) are associated with a higher risk of progression to multiple myeloma.

Diagnosis

Diagnosis necessitates the presence of one or more myeloma-defining events (MDE) in conjunction with evidence of at least 10% clonal plasma cells in a bone marrow examination or a biopsy-proven plasmacytoma.
Myeloma-defining events (MDE): established CRAB features (hypercalcemia, renal failure, anemia, and/or lytic bone lesions), along with 3 specific biomarkers.
- Clonal bone marrow plasma cells >60%
- Serum free light chain (FLC) ratio >100 (with involved FLC level ≥100 mg/L and urinary monoclonal protein excretion ≥200 mg/24hrs)
- More than one focal lesion on MRI
All criteria must be met for diagnosis:
- Clonal bone marrow plasma cells ≥10% or biopsy-proven bony or extramedullary plasmacytoma
- Any one or more of the following myeloma-defining events (MDE): hypercalcemia, renal insufficiency, etc.

Other Tests

24-hour urine collection for protein electrophoresis and immunofixation to monitor urine M protein levels and detect possible renal complications.
Serum free light chain assay is valuable for patients lacking measurable M protein (with abnormal FLC ratio and involved FLC level ≥100 mg/L).

Biochemical Tests

Monitoring M protein level in serum and urine (≥1 g/dL in serum or ≥200 mg/day in urine) and by serum FLC assay (monitored monthly during therapy and every 3-4 months when off-therapy).

Imaging Studies

Low-dose whole-body CT or PET/CT scans are the preferred imaging methods for assessing bone disease.
MRI is helpful to evaluate suspected SMM, extramedullary disease, or suspected cord compression.

Bone Marrow Study

Typically hypercellular
Morphology of plasma cells (PCs) varies
Classical PCs are oval with an eccentric nucleus and abundant basophilic cytoplasm.
In some cases, plasma cells may show atypical features (e.g., Mott cells, plasmacytoses).

Other Plasma Cell Disorders

Includes Non-IgM MGUS, characterized by serum monoclonal protein <3g/dL, clonal bone marrow plasma cells <10%, and absence of CRAB features.
Also includes smoldering myeloma, characterized by serum monoclonal protein (and/or monoclonal protein in urine) and/or clonal bone marrow plasma cells (10-60%) without evidence of CRAB .

Clinical Presentation/Diagnosis

A few cases may have insufficient BM aspirate or focal distribution of myeloma in the marrow, resulting in less than 10% PCs.

Solitary Plasmacytoma

Criteria require a biopsy-proven solitary lesion of bone or soft tissue, with evidence of clonal plasma cells and a normal bone marrow with no clonal plasma cells.
No evidence of other myeloma defining events or amyloidosis . A normal skeletal survey and MRI (except for the primary solitary lesion) of the spine and pelvis.

Solitary Plasmacytoma with Minimal Marrow Involvement

Meets the criteria for solitary plasmacytoma, but with less than 10% clonal bone marrow plasma cells.

Molecular Cytogenetic Classification (Table 1)

Classifies multiple myeloma based on affected genes/chromosomes. This includes hyperdiploid myeloma, IgH translocated myeloma, and others.

Prognosis and Risk Stratification

Overall survival in transplant-eligible patients is >10 years. However, for elderly ( >75 years) patients, median survival is approximately 5 years.
Prognosis factors include the clinical stage of disease, cytogenetic abnormalities (e.g., t(4;14), del(17p), and gain (1q), host characteristics, and response to therapy.
The Durie-Salmon staging system and the International Staging System (ISS) are used to assess tumor burden and predict prognosis.

Disease Biology

Reflected by multiple myeloma subtype (table 1), the presence/absence of secondary cytogenetic abnormalities (del17p, gain1q, del1p), elevated lactate dehydrogenase, and the presence of plasma cell leukemia in peripheral blood smear.

Risk Groups of Multiple Myeloma

Standard risk: trisomies, t(11;14), and t(6;14)
High risk: t(4;14), t(14;16), t(14;20), del(17p), and gain(1q), del(1p)
Double and Triple-Hit Multiple Myeloma: Combination of these high risk factors

References

https://onlinelibrary.wiley.com/doi/full/10.1002/ajh.27422
WHO Haematolymphoid Tumours (5th edition).

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Description

This quiz tests your knowledge on the features observed in peripheral blood (PB) smears, specifically focusing on Rouleaux formation and plasma cells. Explore the implications of these findings and variations in plasma cell counts. Answer questions to further your understanding of hematological assessments.