BCSE Pathology 3

Question 1

A 25-year-old woman presents with a painless neck mass. Biopsy shows lymphocytes, plasma cells, eosinophils, and Reed-Sternberg cells. What is the most likely diagnosis?

Accepted Answer

Hodgkin lymphoma

Answer

Reed-Sternberg cells (large binucleate cells with prominent 'owl-eye' nucleoli) are the pathognomonic hallmark of Hodgkin lymphoma.

Question 2

Which type of hypersensitivity reaction underlies contact dermatitis caused by poison ivy?

Accepted Answer

Type IV (delayed/cell-mediated)

Answer

Contact dermatitis is a Type IV (delayed-type) hypersensitivity reaction mediated by sensitized CD4+ T cells, not antibodies.

Question 3

A newborn has ambiguous genitalia. Karyotype is 46,XX. Serum 17-hydroxyprogesterone is markedly elevated. Which enzyme deficiency is most likely?

Accepted Answer

21-hydroxylase

Answer

21-hydroxylase deficiency is the most common cause of congenital adrenal hyperplasia and causes virilization of female fetuses due to androgen excess.

Question 4

On histology, a thyroid nodule shows cells arranged in follicles with 'Orphan Annie eye' nuclei and nuclear grooves. What is the diagnosis?

Accepted Answer

Papillary carcinoma

Answer

Papillary thyroid carcinoma is characterized by 'Orphan Annie eye' (empty-appearing) nuclei, nuclear grooves, and psammoma bodies.

Question 5

A 70-year-old man is found to have a left renal mass on CT. Microscopically the tumor shows clear cells with abundant lipid and glycogen. What is the most likely diagnosis?

Accepted Answer

Clear cell renal cell carcinoma

Answer

Clear cell renal cell carcinoma is the most common renal malignancy in adults and shows characteristic clear cytoplasm due to lipid and glycogen accumulation.

BCSE - Basic and Clinical Sciences Examination Practice Test

BCSE - Basic and Clinical Sciences Examination Practice Test

BCSE Pathology 3