Anatomic Pathology Flashcards

Which of the following is the most common type of lung cancer in the United States?

Answer: Non-small cell lung cancer

Lung cancer is broadly divided into two main types: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Non-small cell lung cancer accounts for approximately 85% of all lung cancers in the United States, encompassing subtypes like adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Its prevalence makes it the most common type.

What is the characteristic histologic feature of Crohn’s disease?

Answer: Granulomas

Crohn's disease is a chronic inflammatory bowel disease that can affect any part of the gastrointestinal tract. A characteristic histologic feature, though not always present, is the presence of non-caseating granulomas in the bowel wall. These granulomas are aggregates of epithelioid macrophages and lymphocytes, distinguishing Crohn's disease from ulcerative colitis.

Which of the following is the most common site of metastasis for prostate cancer?

Answer: Bone

Prostate cancer frequently metastasizes, and the most common site for its spread is the bone, particularly the axial skeleton (spine, pelvis, ribs). These bone metastases are typically osteoblastic, meaning they stimulate new bone formation, and can cause significant pain and complications. Early detection and treatment are crucial to prevent such spread.

Which type of skin cancer is associated with the highest mortality rate?

Answer: Melanoma

While basal cell carcinoma and squamous cell carcinoma are more common, melanoma is the most aggressive and deadliest form of skin cancer. It has a high propensity for metastasis to distant organs if not detected and treated early, leading to a significantly higher mortality rate compared to other skin cancers. Early diagnosis is critical for improving prognosis.

What is the most common genetic mutation in colorectal cancer?

Answer: KRAS mutation

Colorectal cancer development is often driven by a series of genetic mutations. Among these, mutations in the KRAS gene are one of the most common, occurring in approximately 30-50% of colorectal cancers. KRAS mutations are significant as they activate downstream signaling pathways that promote cell growth and proliferation, and they also have implications for targeted therapy selection.

Which of the following is the hallmark feature of hepatic cirrhosis on histopathological examination?

Answer: Portal fibrosis

Hepatic cirrhosis is a chronic liver disease characterized by diffuse fibrosis and the formation of regenerative nodules, leading to architectural distortion of the liver. On histopathological examination, the hallmark feature is extensive bridging fibrosis, particularly portal fibrosis, which connects portal tracts to central veins, disrupting normal liver structure and function.

What is the most common type of thyroid cancer?

Answer: Papillary thyroid cancer

Papillary thyroid cancer is by far the most common type of thyroid malignancy, accounting for approximately 80-85% of all thyroid cancers. It typically has an excellent prognosis, especially when detected early, and is characterized histologically by distinctive nuclear features such as 'orphan Annie eye' nuclei and nuclear grooves. Its prevalence makes it the most frequently encountered thyroid cancer.

Which of the following findings is most characteristic of a myocardial infarction on histology within the first 24 hours?

Answer: Coagulative necrosis

Myocardial infarction involves ischemic cell death due to lack of blood flow. Within the first 24 hours of an acute myocardial infarction, the most characteristic histological finding is coagulative necrosis. This type of necrosis is typical of ischemia in solid organs like the heart, where the cell's architecture is preserved but nuclei are lost and cytoplasm becomes intensely eosinophilic, indicating irreversible cell injury before significant inflammatory response or repair processes begin.

Which of the following is a key histopathologic feature of Alzheimer's disease?

Answer: Neurofibrillary tangles

Neurofibrillary tangles are a hallmark histopathological feature of Alzheimer's disease. These intracellular aggregates are composed of hyperphosphorylated tau protein, which disrupts neuronal transport and function, leading to neuronal dysfunction and death. While beta-amyloid plaques are also crucial, neurofibrillary tangles correlate more strongly with the degree of cognitive decline and neuronal loss observed in Alzheimer's patients.