12 - White Blood Cells, Lymph Nodes, Spleen, and Thymus

Drug toxicity

Most common cause of neutropenia

Immune destruction

Etiopathogenesis of neutropenia in SLE

Lymphopenia

Type of leukopenia observed in advanced HIV

Leukemoid reaction

Increased WBC count ( ≥ 50×109/L) in the absence of myeloproliferative neoplasm

Leukocyte alkaline phosphatase (LAP) (Normal LAP score in leukemoid reaction; Low in CML)

A cytochemical stain used to differentiate leukemoid reaction from CML

Follicular hyperplasia

Form of lymphadenitis in a patient with rheumatoid arthritis who present with chronic painless lymph node enlargement

Paracortical hyperplasia

Expansion of interfollicular (T-cell) zones in lymph nodes during a viral infection

Leukemia

A 7-year-old male presents with pallor, recurrent infections, and easy bruising. CBC showed leukocytosis with elevated bands, anemia, and thrombocytopenia. What is the most likely initial diagnosis?

Acute lymphoblastic leukemia/lymphoma

Most common cancer in children

Tdt (terminal deoxynucleotidyl transferase)

Immunostain used to identify immature lymphoid process

Acute myeloid leukemia

A patient presented with the following results: PBS - (+) Auer rods, (+) ****** cells. Immunostain - (+) MPO

Disseminated intravascular coagulation

Hematologic emergency associated with acute promyelocytic leukemia

Chronic lymphocytic leukemia (CLL)

Most common leukemia in adults in the Western world

Smudge cells

Fragile lymphocytes that are flattened in the process of smearing blood of CLL patients

Richter syndrome

Transformation of CLL to Diffuse Large B-cell Lymphoma

t(9;22)→BCR::ABL1 fusion (Tyrosine kinase)

Etiology of Chronic Myeloid Leukemia (CML)

Blast phase

A known CML patient refuses to undergo treatment. 5 years later, PBS showed ≥20% blasts. Which phase is the patient currently in?

Hairy cell leukemia

Dry tap on bone marrow is common in this type of leukemia due to marrow fibrosis or increased reticulin fiber deposition; Immunostain: (+) TRAP

Reed-Sternberg cells

Cells with Large, multiple nuclei or single with multiple lobes; each with nucleolus ("Owl-eye nucleus")

Hodgkin Lymphoma

Reed-Sternberg cells are seen in which type of lymphoma

Nodular sclerosis (NSHL)

Most common Hodgkin Lymphoma subtype

Lymphocyte-depleted (LDHL)

Least common Hodgkin Lymphoma subtype but has the worst prognosis; seen in HIV patients

Ann-Arbor stage

Staging system used in the prognosis of lymphoma

Mantle cell lymphoma

Type of non-Hodgkin lymphoma (NHL) associated with lymphomatous polyposis of the GI tract

Follicular lymphoma

Most common form of indolent NHL

Diffuse Large B-cell Lymphoma

Most common NHL

Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue (MALToma)

Type of NHL associated with chronic inflammatory disorders such as H. pylori gastritis, Hashimoto thyroiditis

Burkitt Lymphoma

Type of NHL with bimodal distribution. Typical PBS show starry sky pattern or sheets of medium-sized atypical lymphocytes) with tingible body macrophages

Plasma cells

Type of lymphocytes elevated in Multiple Myeloma

CRAB -HyperCalcemia, Renal failure, Anemia, Bone lesions

Myeloma-defining events

Bence-Jones protein

Protein detected in urine of multiple myeloma patients

Monoclonal gammopathy (IgG)

Serum protein electrophoresis finding in multiple myeloma

Dysplasia in one or more myeloid lineages

Hallmark of myelodysplastic syndromes or defective hematopoietic maturation

JAK2 V617F mutation

Common mutation in myeloproliferative neoplasms

Polycythemia vera

Most likely diagnosis in a patient with facial plethora (redness). pruritus worsened by bathing, and elevated Hgb

Dacryocyte

In primary myelofibrosis, RBCs assume this teardrop-shaped poikilocyte due to squeezing from fibrotic marrow

Liver cirrhosis

Chronic venous congestion of the spleen occurs in the setting of

Thymic Aplasia

Thymic disorder seen in DiGeorge Syndrome

Thymic follicular hyperplasia

Most common thymic disorder associated with myasthenia gravis

Thymoma

Most common thymic epithelial tumor

Myasthenia gravis

Immune paraneoplastic syndrome associated with thymoma

Squamous cell carcinoma

Most common histology of thymic carcinoma