WBR0874

Author	[[PageAuthor::Serge Korjian M.D. (Reviewed by Serge Korjian)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathophysiology
Sub Category	SubCategory::Pulmonology
Prompt	[[Prompt::A 66-year-old man presents to the pulmonary clinic for a cough that has been present for the past 3 months. The patient reports recent fatigue and joint pain that has been interfering with his daily activities. He also reports significant morning stiffness lasting at least an hour and sometimes more. The patient has never smoked in his life and denies any recent sick contacts or travel. Further questioning reveals that he worked for several years as a coal miner but retired 2 years ago. Chest x-ray reveals 3 pulmonary nodules of approximately 1.5 cm each. PPD does not show any induration. Blood analysis reveals excess IgM antibodies reactive to the Fc portion of IgG. What is the most likely diagnosis in this patient?]]
Answer A	AnswerA::Small cell lung cancer
Answer A Explanation	AnswerAExp::Small cell lung cancer is a neoplasm of neuroendocrine origin associated with several paraneoplastic manifestations. It is usually not associated with rheumatoid arthritis.
Answer B	AnswerB::Asbestosis
Answer B Explanation	AnswerBExp::Asbestosis occurs in patients with chronic exposure to asbestos and leads to calcification of the pleura of the lower lobes. Asbestosis has only been rarely reported to be associated with Caplan syndrome.
Answer C	AnswerC::Caplan Syndrome
Answer C Explanation	AnswerCExp::Caplan syndrome also known as rheumatoid pneumoconiosis is characterized by coal miner's pneumoconiosis with associated rheumatoid arthritis with the classical presentation seen in our patient.
Answer D	AnswerD::Coal miner's pneumoconiosis
Answer D Explanation	AnswerDExp::Although this patient is likely to have coal miner's pneumoconiosis, this diagnosis alone is not sufficient to explain all the associated findings usually seen in rheumatoid arthritis.
Answer E	AnswerE::Idiopathic pulmonary fibrosis
Answer E Explanation	AnswerEExp::IPF is a chronic pulmonary disease characterized by progressive parenchymal fibrosis with no identifiable underlying etiology. IPF is not associated with rheumatoid arthritis.
Right Answer	RightAnswer::C
Explanation	[[Explanation::Caplan syndrome also known as rheumatoid pneumoconiosis is a combination of rheumatoid arthritis and pneumoconiosis particularly coal miner's type. Caplan syndrome usually presents with cough and dyspnea related to the lung disease associated with signs and symptoms of rheumatoid arthritis including arthralgias, morning stiffness, swollen MCP and PIP joints and rheumatoid nodules that can often be seen on chest radiography and confused with malignancy or mycobacterial infection. Patients with Caplan syndrome usually have positive rheumatoid factor (antibody against the Fc portion of IgG) although the finding is not specific for the disease. Management is targeted at pain control and immunosuppression. Educational Objective: Caplan syndrome also known as rheumatoid pneumoconiosis is characterized by coal miner's pneumoconiosis with subsequent development of concomitant rheumatoid arthritis. References: Schreiber J, Koschel D, Kekow J, Waldburg N, Goette A, Merget R. Rheumatoid pneumoconiosis (Caplan's syndrome). Eur J Intern Med. 2010;21(3):168-72.]]
Approved	Approved::Yes
Keyword	WBRKeyword::Caplan Syndrome, WBRKeyword::Rheumatoid arthritis, WBRKeyword::Coal miner's pneumoconiosis
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