American Board of Internal Medicine (ABIM) Certification Practice Exam

Which malignancy is characterized by the involvement of lymph nodes on the same side of the diaphragm in early stages?

1. Non-Hodgkin lymphoma

2. Acute myeloid leukemia

3. Hodgkin lymphoma

4. Chronic lymphocytic leukemia

The correct answer is: Hodgkin lymphoma

Hodgkin lymphoma is uniquely characterized by its initial involvement of lymph nodes on the same side of the diaphragm. This pattern of spread is a result of contiguous lymphatic dissemination, where the disease typically affects lymph nodes that are adjacent to one another. In the early stages, patients often present with lymphadenopathy that is localized, frequently observed in the cervical, supraclavicular, or mediastinal regions, which are on the same side of the diaphragm. The distinction of Hodgkin lymphoma from other malignancies is notable, as other forms such as Non-Hodgkin lymphoma, acute myeloid leukemia, and chronic lymphocytic leukemia have different patterns of lymphatic or systemic involvement that do not follow this early-stage localization associated with diaphragm anatomy. For instance, Non-Hodgkin lymphoma can present with more multifocal lymphadenopathy and variable sites of involvement that are not restricted to one side of the diaphragm. Understanding this characteristic localization is crucial for diagnosis and can aid in determining staging and treatment approaches for Hodgkin lymphoma.