HTL Histopathology & Diagnostic Techniques 2

Question 1

Which immunohistochemical marker is most useful for identifying neuroendocrine differentiation in a poorly differentiated carcinoma?

Accepted Answer

Synaptophysin

Answer

Synaptophysin is a pan-neuroendocrine marker expressed in neuroendocrine tumors and is highly sensitive for identifying neuroendocrine differentiation.

Question 2

In the Congo red stain for amyloid, what is the characteristic appearance under polarized light?

Accepted Answer

Apple-green birefringence

Answer

Amyloid deposits stained with Congo red exhibit apple-green birefringence under polarized light, a hallmark diagnostic feature.

Question 3

A biopsy shows cells with pale cytoplasm, perinuclear clearing, and 'raisinoid' nuclei. Which condition does this pattern suggest?

Accepted Answer

Koilocytic change from HPV infection

Answer

Koilocytes — cells with perinuclear halos and wrinkled ('raisinoid') nuclei — are the cytopathic effect of HPV infection seen in squamous epithelium.

Question 4

The Warthin-Starry stain is specifically used to identify which type of organism in tissue sections?

Accepted Answer

Spirochetes and small gram-negative bacteria

Answer

The Warthin-Starry silver stain visualizes spirochetes (e.g., Treponema pallidum) and small bacteria such as Helicobacter pylori and Bartonella species.

Question 5

Which histological feature best distinguishes invasive ductal carcinoma of the breast from ductal carcinoma in situ (DCIS)?

Accepted Answer

Tumor cells penetrating through the basement membrane

Answer

The defining feature of invasive carcinoma is breach of the basement membrane with tumor cells infiltrating surrounding stroma.

(HTL) Histotechnology Certification Practice Test

(HTL) Histotechnology Certification Practice Test

HTL Histopathology & Diagnostic Techniques 2