Anatomic and Clinical Pathology Flashcards

A 45-year-old patient's urine sediment shows waxy casts with low-power refractility and broad diameter. These casts are most indicative of which condition?

Answer: Advanced chronic renal failure

Broad waxy casts form in dilated, damaged tubules and indicate end-stage renal disease with markedly reduced urine flow.

On a bone marrow biopsy, you find sheets of plasma cells with eccentrically placed nuclei and 'clock-face' chromatin comprising 40% of marrow cellularity. Which additional laboratory finding would confirm multiple myeloma?

Answer: Monoclonal protein (M-spike) on serum protein electrophoresis

Multiple myeloma is confirmed by identifying a monoclonal immunoglobulin (M-protein) on serum or urine protein electrophoresis in conjunction with clonal plasma cell proliferation.

A 30-year-old woman has a thyroid nodule. Fine needle aspiration cytology shows follicular cells arranged in a papillary configuration with nuclear features including ground-glass nuclei, nuclear grooves, and pseudoinclusions. What is the diagnosis?

Answer: Papillary thyroid carcinoma

Papillary thyroid carcinoma is diagnosed by its characteristic nuclear features: Orphan Annie eye nuclei (ground-glass), nuclear grooves, and intranuclear pseudoinclusions.

Flow cytometry of a lymph node biopsy from a 60-year-old shows a B-cell population co-expressing CD5 and CD23 with weak surface immunoglobulin. What is the most likely diagnosis?

Answer: Chronic lymphocytic leukemia/small lymphocytic lymphoma

CLL/SLL is characterized by co-expression of CD5 and CD23 with dim surface Ig, distinguishing it from mantle cell lymphoma which is CD5+ but CD23-.

A 25-year-old male presents with a mediastinal mass. Biopsy shows large cells with bilobed nuclei and prominent eosinophilic 'owl-eye' nucleoli in a background of lymphocytes, eosinophils, and plasma cells. What is the diagnosis?

Answer: Nodular sclerosis Hodgkin lymphoma

Reed-Sternberg cells with owl-eye nucleoli in an inflammatory background define classical Hodgkin lymphoma, with nodular sclerosis being most common in young adults with mediastinal involvement.

A 40-year-old with history of ulcerative colitis undergoes colectomy. The specimen shows dysplastic crypts with complex back-to-back glands and nuclear stratification confined to the mucosa. What is the most appropriate diagnosis?

Answer: High-grade dysplasia

High-grade dysplasia in inflammatory bowel disease is characterized by complex architectural distortion and marked nuclear atypia without invasion through the muscularis mucosae.

A CBC shows hemoglobin of 7.2 g/dL with MCV of 115 fL, and the peripheral smear reveals hypersegmented neutrophils (>5 lobes). What is the most likely underlying cause?

Answer: Vitamin B12 or folate deficiency

Macrocytic anemia with hypersegmented neutrophils is the hallmark of megaloblastic anemia caused by vitamin B12 or folate deficiency impacting DNA synthesis.