Plasma Cell Dyscrasias

Question 1

Plasma Cell Neoplasms (Dyscrasias)

What happens here?

Answer 1

B-cell clone that usually synthesizes and usually secretes a single homogeneous immunoglobulin or its fragments
Often referred to as plasma cell dyscrasia
Monoclonal Ig in the blood is referred to as “M component”, monoclonal protein, dysproteinemia or paraproteinemia

Rouleaux

Question 2

Bence Jones protein

Answer 2

Neoplastic plasma cells often synthesize excess light or heavy chains along with complete immunoglobulins

Free L (light) chains in the urine are known as Bence Jones protein

Question 3

Clinicopathologic Entities Associated with Monoclonal Gammopathy

Answer 3

Multiple myeloma
Plasmacytoma
Smoldering Myeloma (like pre-myeloma) ~75% per progress to multiple myeloma within 15 years
Heavy (Light) Chain Disease
Waldenstrom Macroglobulinemia:
Primary or immunocyte-associated amyloidosis
Monoclonal gammopathy of undetermined significance (1% per year progress to multiple myeloma)

Question 4

Monoclonal gammopathy of undetermined significance (MGUS):

Answer 4

M components <3 gm/dL identified in blood, but no signs or symptoms
~1% per year progress to multiple myeloma

Question 5

Multiple Myeloma path

Answer 5

more common in Blacks

age 50-80,
renal failure typically kills the patient

Rarely develop plasma cell leukemia

IL-6 drives proliferation
Tumor M1P1α upregulates RANKL

Express CD38, CD138, CD79a and cytoplasmic immunoglobulins

Do not usually express CD19

Loves to go to bones
like upper airway area

Question 6

Solitary plasmacytoma

Answer 6

like multiple myeloma but there’s only one location

Question 7

Plasma Cell Findings Due to Immunoglobulin Accumulation

Answer 7

Russel body – large intracytoplasmic inclusion
Mott cell – multiple smaller intracytoplasmic inclusions
Flame cell – more diffuse cytoplasmic eosinophilia
Dutcher body – intranuclear inclusion

Question 8

Multiple Myeloma Clinical Features:

Answer 8

Lytic bone lesions → pathologic fractures and substantial bone pain
Hypercalcemia (metastatic calcification)
Suppression of humoral immunity recurrent infections
Renal insufficiency

Monoclonal gammopathy: IgG

Question 9

Lymphoplasmacytic Lymphoma

Answer 9

B-cell neoplasm of older adults; presents in 6th & 7th decade
*** Common cause of Waldenstrom Macroglobulinemia (IgM)

Morphology: lymphocytes, plasma cells, and intermediate forms; Immunoglobulin inclusions (Russell bodies –cytoplasm; Dutcher bodies-nucleus)

Genetics: MYD88 mutations leading to NF-κB activation

[Immunophenotype: Positive for CD19, CD79a, surface and cytoplasmic immunoglobulins (IgM, IgD, IgG or IgA); also variable CD20, and CD38]

Question 10

Lymphoplasmacytic Lymphoma Clinical Features

Answer 10

**Lymphadenopathy, hepatomegaly and splenomegaly

**~50% have Hyperviscosity Syndrome from high levels IgM

Visual Impairment
Neurologic problems: dizziness, deafness & stupor
Bleeding
Cryoglobulinemia
No lytic bone lesions
Usually no Bence-Jones proteinuria or amyloidosis

Prognosis: Incurable with median survival 4-6 years from time of diagnosis