Overview Of RBC And WBC Disorders

1.

A 61-year-old male gives a history of back pain for several months. A radiograph of the spine reveals several 1 to 2 cm lytic lesions of the vertebral bodies. He has no LN or splenomegaly. His serum BUN & creatinine are steadily rising. He recently developed a cough productive of yellowish sputum; sputum culture grew Streptococcus pneumoniae. BM smear is shown here. Which of the following is the most likely diagnosis?

A.

DIC
B.

Primary myelofibrosis
C.

CML
D.

AIDS
E.

Multiple myeloma

Correct Answer
E. Multiple myeloma

Explanation
A. Incorrect. Elevated D-dimers are seen in DIC associated with AML-M3.
B. Incorrect. Tear drop cells are seen in primary myelofibrosis on the peripheral smear. Bone marrow aspirate would be hypocellular and biopsy shows fibrosis.
C. Incorrect. CML shows decreased LAP score, massive splenomegaly and does not show lytic lesions of bone.
D. Incorrect. Patients with AIDS show low CD4 counts.
E. Correct. Plasma cell increase in the bone marrow, lytic bone lesions and elevated BUN and creatinine are diagnostic of MM.

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2.

A 61-year-old man has had dull, constant back pain for 3 months. He recently developed a cough productive of yellowish sputum. Physical examination reveals crackles at right lung base. A plain X-ray film of spine reveals several 1- 2 cm lytic lesions of vertebral bodies. Lab. studies show BUN 49 mg/dL, creatinine 5 mg/dL and Bence-Jones proteinuria. Sputum culture grows Strepto. pneumoniae. Which of the following pathologic findings is most likely to be seen in a BM biopsy from this man?

A.

Scattered small granulomas
B.

Nodules of small mature lymphocytes
C.

Occasional Reed-Sternberg cells
D.

Numerous plasma cells
E.

Hypercellularity with many myeloblasts

Correct Answer
D. Numerous plasma cells

Explanation
(D) Correct. Findings suggest multiple myeloma. Renal failure and increased risk for encapsulated bacterial infections is typical.
(A) Incorrect. Granulomas are unlikely to produce lytic lesions, and they are unlikely to be seen in association with bacterial sepsis
(B) Incorrect. CLL or lymphoma involving BM does not produce lytic lesions. Splenomegaly or lymphadenopathy is likely to occur, though.
(C) Incorrect. Reed-Sternberg cells are indicative of Hodgkin disease, which typically does not produce lytic lesions
(E) Incorrect. An acute myeloid leukemia does not produce lytic lesions and is unlikely at his age.

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3.

A 55-year-old man presents with enlarged lymph nodes. Physical examination shows mild hepato-splenomegaly. Lymph node biopsy shows small lymphocytes, plasmocytoid lymphocytes with Russel bodies. Immunohisto-chemistry shows cytoplasmic IgM accumulation. What is your diagnosis?

A.

MGUS
B.

Solitary plasmacytoma
C.

Waldernstrom disease
D.

Multiple myeloma
E.

Burkitt lymphoma

Correct Answer
C. Waldernstrom disease

Explanation
C. Waldenstrom disease is a neoplastic proliferation of small lymphocytes and a variable no. of IgM secreting plasma cells. 80% patients have a monoclonal IgM spike on EP. Usual symptoms are related to hyperviscosity.

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4.

A 62-year-old man has had increasing lethargy for the past 6 months. On physical examination there are no abnormal findings. Laboratory studies show his serum urea nitrogen is 42 mg/dL with creatinine 4.6 mg/dL. A urinalysis shows B-J proteins. Serum protein electrophoresis reveals a 4 gm monoclonal gamma spike. Which of the following laboratory test findings is this man most likely to have?

A.

Lymphocytosis
B.

Elevated erythrocyte sedimentation rate (ESR)
C.

Positive antinuclear antibody (ANA) test
D.

Hypocalcemia
E.

Macrocytic anemia

Correct Answer
B. Elevated erythrocyte sedimentation rate (ESR)

Explanation
B) CORRECT. The gamma globulins with myeloma increase the sedimentation rate of RBC's. Globulins are poorly detected by urinalysis dipsticks, which mainly detect albumin. The plasma cells that secrete immunoglobulins in myeloma are usually well-differentiated. Patients with multiple myeloma and monoclonal gammopathy may develop renal failure.
A). Incorrect. The plasma cells of myeloma are well-differentiated and secrete immunoglobulins. There are no changes to the cellular elements of the blood except for cytopenias from marrow failure.
(C) Incorrect. The monoclonal spike suggests myeloma, and not a hyperglobulinemia from a reactive condition such as an autoimmune disease.
(D) Incorrect. The bone lesions of multiple myeloma lead to hypercalcemia quite often.
E) Incorrect. Patients with multiple myeloma often have anemia, but it is anemia of chronic disease and normocytic.

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5.

A 59-year-old man has experienced fevers and progressive weight loss of 6 kg over the past 7 months. O/E - Febrile. His spleen tip is palpable. There are enlarged non-tender right inguinal lymph nodes. An abdominal CT scan shows splenomegaly and para-aortic lymphadenopathy. An inguinal lymph node biopsy is performed and on microscopic examination there are small lymphocytes, plasma cells, eosinophils, neutrophils, macrophages, and multinucleated cells. The multinucleated cells mark with an immuno-histochemical stain for CD15 and CD30. Which of the following is the most likely diagnosis?

A.

Disseminated tuberculosis
B.

Hodgkin lymphoma
C.

Langerhans cell histiocytosis
D.

Mycosis fungoides
E.

Sarcoidosis

Correct Answer
B. Hodgkin lymphoma

Explanation
(B) CORRECT. He has the mixed cellularity type of Hodgkin lymphoma, the 2nd most common type, which is usually seen in older adult men. There are abundant Reed-Sternberg cells that are CD15 positive. Constitutional 'B' symptoms of fever, night sweats, and weight loss are often present.
A.) Incorrect. There should be granulomas with caseation, and no Reed-Sternberg cells.
(C) Incorrect. Langerhans cell histiocytosis includes CD1a positive cells.
(D) Incorrect. Mycosis fungoides is a CD4 cell proliferation involving the skin.
(E) Incorrect. Sarcoidosis has non-caseating granulomas without Reed-Sternberg cells.

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6.

A 45-year-old man has noted a change in the appearance of his face over the past 7 months. On examination, his facial skin is thickened and reddened. A punch biopsy of skin shows infiltration by neoplastic T lymphocytes. Which of the following is the most likely diagnosis?

A.

Hodgkin disease
B.

Mycosis fungoides
C.

Burkitt lymphoma
D.

Acute lymphocytic leukemia
E.

Hairy cell leukemia

Correct Answer
B. Mycosis fungoides

Explanation
B. Correct. Mycosis fungoides is a cutaneous T cell lymphoma, composed of mature T-lymphocytes. Skin Bx shows lymphocytic infiltrates at dermo-epidermal junction (epidermotropism) and in some cases, intra-epidermal accumulations of tumor cells (Pautrier’s micro-abscesses)

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7.

A 5-year-old girl is brought by her mother who states that the girl has been drinking too much water. On examination, eyes appear protruded. Radiology reveals multiple lytic lesions involving calvarium & base of skull. What is your diagnosis?

A.

Eosinophilic granuloma
B.

Hand-Schuller-Christian disease
C.

Letterer-Siwe disease
D.

Multiple myeloma
E.

Mycosis fungoides

Correct Answer
B. Hand-Schuller-Christian disease

Explanation
B. Correct. Presentation between 2-6 yrs, features of diabetes insipidus and exophthalmos along with multple lytic bone lesions suggest the diagnosis.

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8.

A 2-year-old boy has had a seborrheic eruption over the scalp and trunk over the past month. He then develops a right ear ache. O/E right tympanic membrane is erythematous and bulging. He has hepato-splenomegaly and generalized LN. Hb 9.5 g/dL, Hct 28.7%, MCV 90 fL, platelet count 58,000/µL, WBC count 3540/µL. BM biopsy shows 100% cellularity with extensive infiltration by cells resembling macrophages that express CD1a antigen and, by EM, have prominent Birbeck granules. Which of the following conditions is most likely to produce this boy's findings?

A.

Myeloproliferative disorder
B.

Plasmodium vivax infection
C.

Hodgkin' disease, nodular sclerosis type
D.

Langerhan cell histiocytosis

Correct Answer
D. Langerhan cell histiocytosis

Explanation
The given clinical presentation of seborrheic eruption, right ear ache, hepato-splenomegaly, generalized lymphadenopathy, and abnormal blood counts is consistent with Langerhan cell histiocytosis (LCH). LCH is a rare disorder characterized by the proliferation of abnormal Langerhans cells, which are a type of dendritic cell. The presence of CD1a antigen expression and Birbeck granules on electron microscopy further support the diagnosis of LCH. Myeloproliferative disorder, Plasmodium vivax infection, and Hodgkin's disease are not associated with these specific findings.

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9.

A 21-yr-old woman complains of generalized weakness, blurred vision, difficulty swallowing. CT scan of the chest shows an anterior mediastinal mass. The mass is removed. Microscopy shows epithelial cells and normal lymphocytes. What is the most likely diagnosis?

A.

Hodgkin’s lymphoma
B.

Burkitt lymphoma
C.

Thymoma
D.

Acute lymphoblastic leukemia

Correct Answer
C. Thymoma

Explanation
C. Correct. Thymomas are associated with myasthenia gravis. They comprise of a tumor of thymic epithelial cells, regardless of the no. of lymphocytes.

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Overview Of RBC And Wbc Disorders

A 55-year-old man presents with enlarged lymph nodes. Physical examination shows mild hepato-splenomegaly. Lymph node biopsy shows small lymphocytes, plasmocytoid lymphocytes with Russel bodies. Immunohisto-chemistry shows cytoplasmic IgM accumulation. What is your diagnosis?

A 45-year-old man has noted a change in the appearance of his face over the past 7 months. On examination, his facial skin is thickened and reddened. A punch biopsy of skin shows infiltration by neoplastic T lymphocytes. Which of the following is the most likely diagnosis?

A 5-year-old girl is brought by her mother who states that the girl has been drinking too much water. On examination, eyes appear protruded. Radiology reveals multiple lytic lesions involving calvarium & base of skull. What is your diagnosis?

A 21-yr-old woman complains of generalized weakness, blurred vision, difficulty swallowing. CT scan of the chest shows an anterior mediastinal mass. The mass is removed. Microscopy shows epithelial cells and normal lymphocytes. What is the most likely diagnosis?