Secondary of all following cause osteolytic lesions except \ \ \ \ \ \ \ ? - Chitranjjan National Cancer Institute Kolkata - 2021

Chitranjjan National Cancer Institute Kolkata - 2021

Pathology & Genetics

Easy

Appeared in: Chitranjjan National Cancer Institute Kolkata - 2021

Explanation

Bone metastases from prostate cancer are characteristically osteoblastic, meaning they stimulate new, often dense and sclerotic, bone formation.
This is in contrast to osteolytic lesions, which involve the destruction and resorption of normal bone tissue.
As per Robbins & Cotran Pathologic Basis of Disease, prostatic adenocarcinoma is predominantly blastic.
Therefore, prostate cancer is the exception among the given choices, as the others typically cause osteolytic lesions.

Option B: Metastases from kidney cancer (renal cell carcinoma) are typically purely osteolytic, causing significant bone destruction.
Option C: Lung cancer (originating in the bronchus) is one of the most common causes of osteolytic bone metastases.
Option D: Metastases from thyroid cancer are also predominantly osteolytic, leading to bone destruction.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Classification of bone metastases (osteolytic vs. osteoblastic) as background academic context rather than a clinical decision trigger.
Differentiating between osteolytic and osteoblastic lesions is crucial for diagnosis and management. Osteolytic lesions carry a higher risk of pathologic fractures, requiring closer monitoring and potential prophylactic surgical fixation.
The type of lesion can guide the diagnostic workup. For instance, finding osteoblastic metastases in a male patient strongly suggests prostate cancer as the primary source, prompting a measurement of Prostate-Specific Antigen (PSA).
Treatment differs. Bisphosphonates and denosumab are used to inhibit osteoclast activity in osteolytic lesions to reduce fracture risk, while treatment for osteoblastic lesions focuses on the primary cancer.

How to Approach the Question

First, identify the keyword 'except'. This signals that you must find the option that is different from the others.
The question asks which cancer does NOT cause 'osteolytic' (bone-destroying) lesions.
Recall the two main types of bone metastases: osteolytic (bone-destroying) and osteoblastic (bone-forming/sclerotic).
Systematically review the options and recall the typical metastatic pattern for each primary cancer.
Recognize that prostate cancer is uniquely known for causing osteoblastic lesions.
Confirm that kidney, bronchus (lung), and thyroid cancers typically cause osteolytic lesions. This makes 'Prostate' the correct exception.

Concept Tested & Keywords

Concept Tested: Classification of bone metastases (osteolytic vs. osteoblastic)
Stem keywords: secondary, osteolytic lesions
Lead-in keywords: except
Negative lead-in flag: The question asks for the exception among the given options, meaning the one that does not cause osteolytic lesions.

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E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 1195-1197