correct answer is C. This patient's history of alcohol abuse, nodular cirrhosis on examination, and elevated bilirubin all suggest that liver pathology may exist. Elevated erythropoietin (EPO) levels are indicative of hepatocellular carcinoma.
Ectopic overproduction of EPO stimulates red blood cell production and causes polycythemia (paraneoplastic erythrocytosis; inappropriate absolute polycythemia). Other EPO-secreting tumors include renal cell carcinoma, hemangioblastoma, and pheochromocytoma.
Types of polycythemia:
Types of Polycythemia
Chronic carbon monoxide exposure (choice B) causes a reactive polycythemia. Consider:
Occupational exposures: work in underground parking garages, taxi drivers with prolonged exposure to car pollution, and industrial workers.
Carboxyhemoglobin can give a falsely high oxygen saturation on pulse oximetry.
Increased carboxyhemoglobin and erythropoietin levels.
Polycythemia vera (choice D) causes primary polycythemia. It is a bone marrow disorder with proliferation of hematopoietic cells, characteristically associated with erythropoiesis, increased viscosity, and low levels of erythropoietin.
Reactive polycythemia (choice E) is a response to hypoxemia that results in an absolute increase in red cell mass. Decreased oxygen saturation on pulse oximetry and elevated erythropoietin level are present. It is commonly seen in:
Congenital cardiac malformations (choice A)
Chronic lung conditions (COPD, pulmonary fibrosis)
Polycythemia can be an important finding to suggest an underlying malignancy (paraneoplastic syndrome).
Hepatocellular carcinoma is associated with increased erythropoietin production (paraneoplastic syndrome).
Secondary polycythemia (e.g., tumors) is related to elevated erythropoietin levels and is distinguished from primary polycythemia vera, which diagnostically has low serum erythropoietin levels.
MedEssentials (4th Ed.): pp. 162
First Aid (2018): pp. 386.1, 421.2
First Aid (2017): pp. 375.1, 411.2
First Aid (2016): pp. 368.1, 404.2
Pathoma (2018): pp. 58.3, 123.3
Pathoma (2014-2017): pp. 58.3, 123.3