Pathology Lab-WBC Disorders Flashcards
A 6-year-old girl is weak and lethargic at school. Her mother notices a “rash” on her daughter’s arms and legs and also reports that her child has been running a low-grade fever. No history of allergies or dermatologic problems. One episode of “strep throat” responded well to penicillin treatment. An older brother is very susceptible to poison ivy. The parents are both in good health. This child is pale and exhibits multiple petechiae on both arms. Her spleen is palpable and tenderness is noted over the long bones. HCT 28%, RBC indices normal. WBC 54,000/mm with 56% blast cells, 4% bands, 10% polys, 8% monocytes, 22% mature lymphocytes and 4 nRBCs/100 RBCs. The platelet count is 22,000/ mm3. What is the most likely diagnosis?
sceptible to poison ivy. The parents are both in good health. This child is pale and exhibits multiple petechiae on both arms. Her spleen is palpable and tenderness is noted over the long bones. HCT 28%, RBC indices normal. WBC 54,000/mm with 56% blast cells, 4% bands, 10% polys, 8% monocytes, 22% mature lymphocytes and 4 nRBCs/100 RBCs. The platelet count is 22,000/ mm3. What is your diagnosis? Note the patient has nucleated red cells and a depleted platelet count due to bone marrow replacement by lymphoblasts. B-cell ALL is the most common pediatric malignancy.
A 22-year-old sailor was transferred from the port of Baltimore to the NNMC by helicopter. He had been complaining of weakness and sweating at night. He had a recent episode of heavy epistaxis. As far as he could recall this never occurred before. Temp 38C, Pulse 110, Resp 22, BP 115/75. There was a grade I systolic murmur. Petechial hemorrhages appeared on his arm after the BP reading and were scattered over both thighs and legs. Hb 10 g/dL, WBC 4,500 cells/mm . The differential count showed mostly blast cells with a few promyelocytes, 20% bands or neutrophils, 6% monocytes, and 16% lymphocytes. The platelet count was 12,000 mm3. Urine positive for myeloperoxidase (MPO). What is the most likely diagnosis?
Note the MPO, this tells you that you have a myeloid leukemia. Platelets are low and he is anemic, indicating marrow replacement by neoplastic cells. 58% blasts tells you that this is an acute leukemia. He most likely has acute myelogenous leukemia (AML).
A 45-year-old Navy commander reported for his annual physical exam. He has an appendectomy at age 25. Review of previous records showed a weight loss of 15 lbs. His father suffered prostate cancer and died at age 71. Questions elicit a history of “fullness” after meals, and he admitted to excessive daytime fatigue. Vital signs were normal. Conjunctival pallor is evident. The spleen is palpated one hand breadth below the left costal margin. The liver is also enlarged. Hb: 11.1 g/dL, HCT 34%, RBC indices normal. WBC: 56,000/ mm3 with 5% blasts, 5% promyelocytes, 5% myelocytes, 5% metamyelocytes, 10% bands, 42% polys, 5%, basophils, 3% eosinophils, 15% lymphocytes, 5% monocytes, Platelets 550,000/ mm3. The leukocyte alkaline phosphatase (LAP) was decreased. FISH and PCR results were diagnostic. What is the most likely diagnosis?
Note that most myeloid cells are elevated, with only 5% blasts, indicating a myeloproliferative disorder with a degree of differentiation. The pleuripotent stem cell has undergone a t(9;22), which causes malignancy in all hematopoietic cells (elevated platelets and WBC count). The increased basophil count and these findings are specific for CML.
A 65 y/o medical officer came with complaints of mild anorexia and progressively increasing weakness and fatigue. Comparison to his previous records disclosed a recent weight loss of 10 lb. He is of European ancestry. His father died at age 80 with a “blood disease”. Further history revealed occasional episodes of gum bleeding which he said were unusual for him. Vital signs were normal but he appeared pale and lethargic. A shotty enlargement of cervical axillary and inguinal lymph nodes was palpated. The liver margin and spleen tip were palpable. Hb 10.1 gm/dL, HCT 30.5%, MCV 90 mm, WBC 56,000/mm with 20% polys and 80% small uniform lymphocytes. Platelet count = 68,000 cells/mm. Retic count within normal range. Flow cytometry showed a large subpopulation of cells positive for CD20 and CD5. A chest radiograph shows enlarged hilar lymph nodes. A direct Coombs test is positive. Cytogenetic analysis of bone marrow cells shows a chromosome 13q deletion as the only abnormality. PCR shows mutation of the IgM gene. What is the most likely diagnosis?
Note marked lymphocytosis w/small lymphocytes, CD20 marks B cells, aberrant CD5 B cells, elderly male, gum bleeding and gradual depletion of bone marrow (indicated by platelet count and his bone marrow biopsy). This is al indicative of CLL.
A 55-year-old African-American Coast Guard officer complains of increasing low back pain. The patient had a positive test for sickle hemoglobin in childhood. The father recently developed prostate cancer. The patient reports some loss of appetite and difficulty with urination. The pulse is increased and the patient has a low grade fever. Some pulmonary rales are noted. There is tenderness over the lower back but no kyphosis or scoliosis. The prostate gland is tender and enlarged. Hb 10.2 gm/dL with normochromic, normocytic indices. WBC 7,800 with 55% polys, 5% monocytes, 12% monocytes, 26% mature lymphocytes and 2% atypical large or plasmacytic lymphocytes. PSA is 7 ng/ml. Serum alkaline phosphatase is 297 U/L. A urine sample is 1+ positive for protein. Serum creatinine is 3.7 mg/dl and the BUN is 35 mg/dL. The total serum protein is 9.3 g/dL with albumin 4.1 g/dL. Serum protein electrophoresis (SPEP) detects a monoclonal “spike” in the gamma globulin region. IgG heavy chains and kappa, but no lambda chains are detected on immunostaining of electrophoresis gels. A deep cough sputum sample is positive for S. pneumoniae. A bone scan shows lesions in the Radiographs show a partial collapse of T11 and several 0.5-1 cm sharply defined “punched out” lytic lesions in the calvarium. CT scan shows no evidence of a primary tumor in the breast, lung or gastrointestinal tract. What is the most likely diagnosis in this patient?
This patient has multiple myeloma. This is a plasma cell neoplasm, these cells only make one type of immunoglobulin type, accounting for the monoclonal spike on SPEP. Note the bone pain, hypercalcemia
What do you see in the bone marrow aspirate shown below?
This is an immature blast. Note that it is larger than red cells, has diffuse loose chromatin, high N:C ratio and multiple punched out nucleoli. Note that it is not possible to distinguish between a lymphoblast or a myeloblast at this stage.
What would you expect to see on bone marrow biopsy in a patient with low platelets, nucleated red cells and blasts in the peripheral blood?
Hypercellular bone marrow
Why is TdT a good marker for immature lymphocytes?
TdT is involved in the rearrangement of heavy and light chains in B cells and gamma and beta chains in T cells. Hence, once surface Ig is put on the cell, you no longer need tDt and it will be absent in mature lymphocytes.
Pan B cell markers
CD19 and CD20 stay with the B cells throughout their differentiation
Hallmark of CLL markers
CD20 and abberent T cell CD5. Note that most developing T cells will express CD5.
Markers present on all mature T-cells
CD2,3
Poor prognostic sign for ALL
T cell leukemia, kids and elderly, Philadelphia chromosome t(9;22) in older people
What type of cell are we looking at in this study?
This is a precursor B-cell marker (CD10, 19 are B cell markers, TdT marks immature cells), typically found in ALL.
Why do you need to get a lumbar puncture and how do you need to treat a kid with B cell ALL?
Check for lymphoblasts in the CSF. Intrathecal and testicular chemotherapy in addition to normal chemotherapy. If you don’t these regions protected from the blood can become a sanctuary for the neoplastic B cells and cause a blast crisis (big B cells cause vascular thrombosis and cerebrovascular hemorrhages).
What do you need to keep in mind about a patient’s white count and leukemia?
You can still have a normal white count.
What condition is indicated by the image below?
Marrow stress, not the nucleated red cell (yellow arrow) and bands (blue arrows).
M0-M3 AML
M0 = undifferentiated. M3 = mostly promyelocytes. M2 is in between.
M4 AML
Myelomonocytic
Where does MPO come from? Why don’t cells in AML have LAP?
The primary azurophilic granules. Leukocyte alkaline phosphatase is produced in the secondary granules and is only seen in cells that are present due to a leukemoid reaction?
When are you most likely to see these?
Note that there is more cytoplasm relative to the nucleus and Auer rods. These are seen in more differentiated myeloid cells, M3.
What type of leukemia has the worst prognosis?
AML
What is the mechanism for development of AML? How does this dictate how we treat AML?
t(15;17) that generates an abnormal retinoic acid receptor. ATRA (all trans retinoic acid) causes activation of the retinoic acid receptor and causes the cells to differentiate.
What would you expect to see on peripheral blood smear in this patient with leukemia?
Note the bean-shaped nuclei, this usually indicates a monocytic cell. This patient most likely has an M4 AML. Myelomonocytic cells infiltrate tissue and present with gum bleeding.
What condition is this very specific for?
Note that after pressing the skin lesion, it turns green. This is a chloroma. These are rare, but very specific for AML. They represent focal collections of AML cells in the underlying skin. They turn green because when you press down, you push the blood out and reveal the underlying MPO which is actually green.
How do you distinguish CML from a leukemoid reaction?
Absent LAP in CML.
What is concerning about splenomegaly?
Possible rupture, increased extravascular hemolysis because RBCs get trapped in the enlarged spleen and a possible indicator for infection (EBV)
What mutation is associated with all forms of CML?
t(9;22). c-abl (oncogene) on 9 and BCR on 22 form a fusion gene that activates tyrosine kinase and the JAK/STAT pathway.
How do you treat CML?
Gleevic. It targets the tyrosine kinase activated by t(9;22). This allows for long-term remission of CML.
How do we currently diagnose and follow CML?
FISH and PCR (both shown below)
What cells would you expect to see on bone marrow biopsy in a patient with CLL?
Mature B cells (won’t have TdT, will have surface Ig) with clumped chromatin. You can also see smudge cells because the old cells burst when you prepare the slide.
What indicates a poor prognosis for CLL?
Immature B-cell (does not have IgM mutation) and positive for ZAP-70.
What is CLL in a lymph node?
Small lymphocytic lymphoma
How is this different from CLL? What is its marker?
This is Hairy Cell Leukemia. It occurs in younger people and has a much better prognosis. Marker = CD11c. It is stained with TRAP (shown below)
Where does CLL like to infiltrate?
Portal tract
What type of splenomegaly does hairy cell leukemia cause?
Red pulp hypertrophy.
What would you see on bone marrow biopsy of a patient who has multiple myeloma?
Neoplastic plasma cell proliferation (some have 2 nuclei)
How does multiple myeloma cause damage?
The plasma cells infiltrate the tissue around the body. They produce RANKL activating factor that activates RANK which causes osteolytic lesions. Excess kappa light chain also gets into the renal tubules and causes toxic kidney damage. Macrophages eat up the light chain and deposit amyloid in the kidney. Rapid cell turnover increases uric acid and causes uric acid deposition in the kidney.
Monoclonal IgM spike. What clinical sign does this lead to?
Waldenstrom’s Macroglobulinemia. Elevated Ig decreases RBC surface charge and causes hyperviscosity leading to thrombosis, hypoxia and edema.
A 28-year-old laboratory technician noted painless swelling on the left side of her neck. She had an episode of infectious mononucleosis in graduate school. Her parents are both professionals and her brother is in college. She complains of occasional episodes pruritis with no apparent cause. An isolated 3 cm diameter cervical lymph node is firm to palpation. A large anterior mediastinal mass is detected radiographically. The cervical lymph node is excised. The cut surface shows broad bands of fibrosis that subdivide the parenchyma. H&E stained paraffin sections of the tumor shows mixed cellularity with lymphocytes, histiocytes, some plasma cells, some eosinophils and lacunar spaces containing multinucleate Reed-Sternberg cells separated by dense fibrous tissue. A immunohistochemical reaction for CD15 is positive. What is the most likely diagnosis?
Immunohistochemical staining show R-S cells. He also has a mediastinal mass. Although he has mixed cellularity he most likely has nodular sclerosis variant Hodgkin lymphoma. Note the lacunar R-S cell characteristic of nodular sclerosis variant Hodgkin lymphoma.
A 14-year-old adolescent male complains of cough and wheezing. His pediatrician made a diagnosis of asthma, but the problem becomes increasingly severe despite use of antihistamines. The patient describes rapid enlargement of lumps in his neck. Physical examination reveals conjunctival and dermal pallor, there is evidence of facial swelling. Several cervical lymph nodes are firm and palpable, Breathing appears labored with nasal flaring and intercostal retractions. CBC: Hb 11 g/dL . Normochromic, normocytic. WBC 18,000/ mm3 with 70% lymphocytes, 28% polys, 2% monocytes. platelets 36,000 / mm3. A chest radiograph shows a large mass involving the anterior mediastinum. A needle aspiration is performed: the lesion consists of densely packed lymphocytes of uniform size with round- ovoid nuclei, delicate chromatin, and small nucleoli. Many mitotic figures are evident. What is the most likely diagnosis?
Note that he has facial swelling, difficulty breathing and a mediastinal mass, indicating SVC syndrome. Note the fine chromatin pattern with small nucleoli (indicating immature cells). This is a common presentation for lymphoblastic T-cell lymphoma.
What would you expect to see on histology of this biopsy?
This is follicular lymphoma
Which of these are from an infection and which is from nodular lymphoma?
The left image is a germinal center reaction w/tingible body macrophages that are phagocytosing apoptotic B cells. The right image shows nodules infiltrating the lymph node and going out into the perinodal fat (shown below).
What happens to the nuclei of the B-cells in follicular lymphoma?
They have a cleaved nucleus, slightly larger than a red cell…”small cleaved cells”
What is the pathogenesis of follicular lymphoma?
In normal follicles, Bcl2 is absent in the germinal center and present in the mantle zone. Apoptosis occurs in the germinal center. In follicular lymphoma, all cells are Bcl2 positive because of t(14;18), which makes all germinal center B-cells resistant to apoptosis.
What would you expect to see on histological examination of this lymph node?
Note the fleshy cut surface typical of DLBCL. You would see very large cells with prominent nucleoli and a thick nuclear membrane with a nuclear clearing. You would also see mitosis.
Key presentations of DLBCL?
Nodal and extranodal presentations (may sometimes be confused with metastatic carcinoma).
What abnormal rearrangement are seen in the conditions below?
Nodular = t(14;18), Diffuse = Bcl6 rearrangements. Mantle = overexpression of cyclin D1.
When are tingible body macrophages a presentation of a pathological condition?
In Burkitt lymphoma tingible body macrophages are scattered in a diffuse sea of lymphocytes.
Where does Burkitt lymphoma typically infiltrate in the GI tract?
Submucosa
What type of reactive cells are seen in mono?
Reactive CD8+ T-cells
What would you expect to see on biopsy of this patient?
Masses of lymphocytes with R-S cells in lacunae.
Types of Hodgkin lymphomas that generally present at stages I and II, with a 90% cure rate with therapy?
Lymphocyte predominant and nodular sclerosis variants of Hodgkin lymphoma.
Types of Hodgkin lymphomas that generally present at stages III and IV, with a < 75% cure rate?
Lymphocyte poor and mixed cellularity variants of Hodgkin lymphoma.
What must you see to diagnose Hodgkin lymphoma?
R-S cells.
What would you expect to see on biopsy of adult T-cell leukemia/lymphoma with a terrible prognosis?
HTLV-1 infection can cause this cancer and presents with a flower-petal appearance.
