LATEST PATHOLOGY CERTIFICATION -
ANATOMIC & CLINICAL EXAM OFFERED BY
AMERICAN BOARD OF PATHOLOGY |
COMPLETE EXAM Q&A WITH RATIONALES
1. A 55-year-old man with a 40-pack-year smoking
history presents with a lung mass. Biopsy shows
nests of malignant cells with peripheral palisading
and central necrosis. The cells are positive for
cytokeratin 7, TTF-1, and synaptophysin. What is the
most likely diagnosis?
A) Squamous cell carcinoma
B) Adenocarcinoma
C) Small cell carcinoma
D) Large cell neuroendocrine carcinoma
Correct answer: C
Rationale: Small cell carcinoma shows nests of small
blue cells with nuclear molding, granular chromatin,
scant cytoplasm, and necrosis. Neuroendocrine
markers (synaptophysin, chromogranin) are positive.
TTF-1 is positive in 90% of small cell carcinoma.
2. A 32-year-old woman presents with a breast mass.
Core needle biopsy shows a tumor composed of
,spindle cells surrounded by lymphocytes. The tumor
cells are positive for CK5/6, EGFR, and p63 but
negative for ER, PR, and HER2/neu. What is the most
likely diagnosis?
A) Fibroadenoma
B) Invasive ductal carcinoma
C) Metaplastic carcinoma
D) Medullary carcinoma
Correct answer: D
Rationale: Medullary carcinoma is a subtype of triple-
negative breast cancer with syncytial growth,
pushing borders, lymphocytic infiltration, and high-
grade nuclei. It has a better prognosis than other
triple-negative carcinomas despite high-grade
features.
3. A 45-year-old man with HIV presents with multiple
cutaneous violaceous plaques on the lower
extremities. Biopsy shows a dermal proliferation of
spindle cells forming slit-like vascular spaces with
extravasated red blood cells. The spindle cells are
positive for HHV-8 LNA-1. What is the most likely
diagnosis?
A) Bacillary angiomatosis
B) Kaposi sarcoma
,C) Angiosarcoma
D) Pyogenic granuloma
Correct answer: B
Rationale: Kaposi sarcoma (KS) is caused by HHV-8
and presents in HIV patients as violaceous
plaques/nodules. Histology shows spindle cells
forming slit-like vascular spaces (prominent in
patch/plaque stage). HHV-8 LNA-1 immunostain is
diagnostic.
4. A 60-year-old woman undergoes right
hemicolectomy for a cecal mass. Gross examination
shows a fungating, ulcerated mass. Microscopy
shows malignant glands with abundant dirty necrosis
and a desmoplastic stromal response. The neoplastic
cells are CK7 negative, CK20 positive, and CDX2
positive. What is the most likely primary site?
A) Lung
B) Breast
C) Colorectum
D) Ovary
Correct answer: C
Rationale: Colorectal adenocarcinoma is typically
CK7 negative, CK20 positive, and CDX2 positive (95%
, of cases). Dirty necrosis and a garland pattern are
characteristic. CK7+/CK20- pattern suggests lung or
breast primary.
5. A 25-year-old woman presents with a painless,
rubbery lymph node in the neck. Excisional biopsy
shows effacement of the nodal architecture by a
proliferation of large B-cells in a background of small
lymphocytes. The large cells are CD20+, CD30+,
CD15-, and EBV+ with a "moth-eaten" appearance on
Giemsa stain. What is the most likely diagnosis?
A) Hodgkin lymphoma, nodular sclerosis type
B) Hodgkin lymphoma, mixed cellularity type
C) Nodular lymphocyte predominant Hodgkin
lymphoma
D) Diffuse large B-cell lymphoma
Correct answer: C
Rationale: Nodular lymphocyte predominant Hodgkin
lymphoma (NLPHL) is characterized by popcorn cells
(lymphocyte predominant cells) that are CD20+,
CD30-, CD15-, and EBV-. It has an indolent course
and often presents as localized cervical adenopathy
in young adults.
ANATOMIC & CLINICAL EXAM OFFERED BY
AMERICAN BOARD OF PATHOLOGY |
COMPLETE EXAM Q&A WITH RATIONALES
1. A 55-year-old man with a 40-pack-year smoking
history presents with a lung mass. Biopsy shows
nests of malignant cells with peripheral palisading
and central necrosis. The cells are positive for
cytokeratin 7, TTF-1, and synaptophysin. What is the
most likely diagnosis?
A) Squamous cell carcinoma
B) Adenocarcinoma
C) Small cell carcinoma
D) Large cell neuroendocrine carcinoma
Correct answer: C
Rationale: Small cell carcinoma shows nests of small
blue cells with nuclear molding, granular chromatin,
scant cytoplasm, and necrosis. Neuroendocrine
markers (synaptophysin, chromogranin) are positive.
TTF-1 is positive in 90% of small cell carcinoma.
2. A 32-year-old woman presents with a breast mass.
Core needle biopsy shows a tumor composed of
,spindle cells surrounded by lymphocytes. The tumor
cells are positive for CK5/6, EGFR, and p63 but
negative for ER, PR, and HER2/neu. What is the most
likely diagnosis?
A) Fibroadenoma
B) Invasive ductal carcinoma
C) Metaplastic carcinoma
D) Medullary carcinoma
Correct answer: D
Rationale: Medullary carcinoma is a subtype of triple-
negative breast cancer with syncytial growth,
pushing borders, lymphocytic infiltration, and high-
grade nuclei. It has a better prognosis than other
triple-negative carcinomas despite high-grade
features.
3. A 45-year-old man with HIV presents with multiple
cutaneous violaceous plaques on the lower
extremities. Biopsy shows a dermal proliferation of
spindle cells forming slit-like vascular spaces with
extravasated red blood cells. The spindle cells are
positive for HHV-8 LNA-1. What is the most likely
diagnosis?
A) Bacillary angiomatosis
B) Kaposi sarcoma
,C) Angiosarcoma
D) Pyogenic granuloma
Correct answer: B
Rationale: Kaposi sarcoma (KS) is caused by HHV-8
and presents in HIV patients as violaceous
plaques/nodules. Histology shows spindle cells
forming slit-like vascular spaces (prominent in
patch/plaque stage). HHV-8 LNA-1 immunostain is
diagnostic.
4. A 60-year-old woman undergoes right
hemicolectomy for a cecal mass. Gross examination
shows a fungating, ulcerated mass. Microscopy
shows malignant glands with abundant dirty necrosis
and a desmoplastic stromal response. The neoplastic
cells are CK7 negative, CK20 positive, and CDX2
positive. What is the most likely primary site?
A) Lung
B) Breast
C) Colorectum
D) Ovary
Correct answer: C
Rationale: Colorectal adenocarcinoma is typically
CK7 negative, CK20 positive, and CDX2 positive (95%
, of cases). Dirty necrosis and a garland pattern are
characteristic. CK7+/CK20- pattern suggests lung or
breast primary.
5. A 25-year-old woman presents with a painless,
rubbery lymph node in the neck. Excisional biopsy
shows effacement of the nodal architecture by a
proliferation of large B-cells in a background of small
lymphocytes. The large cells are CD20+, CD30+,
CD15-, and EBV+ with a "moth-eaten" appearance on
Giemsa stain. What is the most likely diagnosis?
A) Hodgkin lymphoma, nodular sclerosis type
B) Hodgkin lymphoma, mixed cellularity type
C) Nodular lymphocyte predominant Hodgkin
lymphoma
D) Diffuse large B-cell lymphoma
Correct answer: C
Rationale: Nodular lymphocyte predominant Hodgkin
lymphoma (NLPHL) is characterized by popcorn cells
(lymphocyte predominant cells) that are CD20+,
CD30-, CD15-, and EBV-. It has an indolent course
and often presents as localized cervical adenopathy
in young adults.
