ABIM & Internal Medicine Shelf Exam Review Question of the Week: High-Yield Paraneoplastic Syndromes
As we begin #OncologyWeek in our preparation of the ABIM and Internal Medicine Shelf exam review, here is a question directly out of the Knowmedge QVault. Give it your best shot and then see below for the answer.
67-year-old male with an extensive smoking history presents with cough, worsening shortness of breath, hemoptysis and weight loss. He undergoes a CT of the chest, which shows a mass present in the lung. The patient undergoes biopsy that confirms small cell lung cancer. Which of the following paraneoplastic conditions is most likely to be associated with small cell carcinoma?
A. Gynecomastia B. Syndrome that is associated with pain in the hands and legs with xray showing periosteal bone thickening C. Condition associated with shoulder pain and pain in the ulnar aspect of the hand D. Syndrome associated with weakness which resolves with repetition of exercise E. Syndrome associated with ptosis, miosis and anhidrosis
ABIM Exam Practice Question Explanation
Of the various types of cancers, those originating from the lung are the most likely to have accompanying paraneoplastic syndromes. Lung cancers are broken down into small cell carcinoma (oat cell carcinoma) and non-small cell lung cancer. The non-small cell lung cancers are squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. Each can lead to unique paraneoplastic syndromes.
Small cell carcinoma associated paraneoplastic syndromes include:
- SIADH presenting as hyponatremia
- Ectopic ACTH presenting with Cushing syndrome
- Eaton-Lambert syndrome featuring weakness that improves with repetition, no diplopia or ptosis and decreased reflexes
- Carcinoid presenting with flushing and diarrhea
- SVC syndrome from obstruction of superior vena cava, presenting with shortness of breath, facial swelling and increased jugular venous pressure
Squamous cell carcinoma associated paraneoplastic syndrome includes:
- Parathyroid hormone related peptide presenting with hypercalcemia
- Horner’s syndrome presenting with the triad of ptosis, miosis, anhidrosis
- Pancoast tumor compressing the first and second thoracic nerve causing shoulder and ulnar hand pain
Adenocarcinoma of the lung associated paraneoplastic syndrome is:
- Hypertrophic pulmonary osteoarthropathy leading to pain in the hands and legs with x-ray showing periosteal thickening
Large cell carcinoma associated paraneoplastic syndrome symptoms includes:
- Gynecomastia (enlargement of the breasts)
- SVC syndrome – condition associated with facial swelling
A mnemonic to remember these conditions is that large cell causes large breasts and a large face.
Of the above choices, Choice D (Syndrome associated with muscle strength that increases with repetition of exercise) most accurately describes a small cell cancer (Eaton-Lambert syndrome).
Let’s go over the other answer choices:
- Choice A (Gynecomastia) corresponds to large cell carcinoma.
- Choice B (Syndrome that is associated with pain in the hands and legs with xray showing periosteal bone thickening) is describing hypertrophic pulmonary osteoarthropathy, a possible manifestation of adenocarcinoma.
- Choice C (Condition associated with shoulder pain and pain in the ulnar aspect of the hand) is describing Pancoast tumor, seen in squamous cell carcinoma.
- Choice E (Syndrome associated with ptosis, miosis and anhidrosis) is describing Horner’s syndrome, which can be a feature of squamous cell carcinoma.
You can view all the previous ABIM Exam Review Questions of the Week at the Knowmedge Blog. You can also find additional topics and questions directly from the Knowmedge Internal Medicine ABIM Board Exam Review Questions QVault.