A 62-year-old man comes to the office due to an abnormal chest x-ray. Two weeks ago, the patient was seen at an emergency department after a motor vehicle collision. Evaluation showed no significant trauma, but a chest x-ray revealed enlarged mediastinal lymph nodes. The patient has had no fever, cough, or dyspnea but has had nonpainful nodules in his axillae for the past several months. Medical history includes hypertension, for which he takes chlorthalidone. He is lifelong nonsmoker and drinks alcohol occasionally. Vital signs are within normal limits. Physical examination reveals clear lungs and normal heart sounds. Bilateral axillary and inguinal lymph nodes are enlarged and nontender. There is no rash or extremity edema. Blood cell counts and serum chemistry studies are within normal limits. A chest x-ray from a year ago also shows mediastinal lymphadenopathy. Which of the following is the most likely underlying cause of this patient's current condition?

Question

A 62-year-old man comes to the office due to an abnormal chest x-ray.  Two weeks ago, the patient was seen at an emergency department after a motor vehicle collision.  Evaluation showed no significant trauma, but a chest x-ray revealed enlarged mediastinal lymph nodes.  The patient has had no fever, cough, or dyspnea but has had nonpainful nodules in his axillae for the past several months.  Medical history includes hypertension, for which he takes chlorthalidone.  He is lifelong nonsmoker and drinks alcohol occasionally.  Vital signs are within normal limits.  Physical examination reveals clear lungs and normal heart sounds.  Bilateral axillary and inguinal lymph nodes are enlarged and nontender.  There is no rash or extremity edema.  Blood cell counts and serum chemistry studies are within normal limits.  A chest x-ray from a year ago also shows mediastinal lymphadenopathy.  Which of the following is the most likely underlying cause of this patient's current condition?

Quizplus · Accepted Answer

This patient's long-standing lymphadenopathy raises suspicion for follicular lymphoma, a common form of non-Hodgkin lymphoma (NHL) that often presents in elderly patients. Most cases present in an indolent fashion with months or years of painless peripheral lymphadenopathy in the cervical, axillary, or inguinal region. Although hilar and mediastinal lymphadenopathy occurs, large mediastinal masses are rare. The lymphadenopathy can wax and wane. B symptoms (eg, night sweats, fever, weight loss) and laboratory abnormalities (eg, elevated lactate dehydrogenase, cytopenia) are generally absent. Follicular lymphoma is usually diagnosed with excisional lymph node biopsy. Histopathology typically shows nodular growth of follicular lymphocytes, and immunophenotyping most often reveals (in ~85% of cases) a translocation between chromosomes 14 and 18 that leads to the overexpression of BCL-2, an oncogene that prevents apoptosis. (Choice A) Antinuclear antibody is a diagnostic marker for systemic lupus erythematosus (SLE). Although patients with uncontrolled SLE sometimes have peripheral lymphadenopathy, other diagnostic manifestations (eg, arthralgia, rash, serositis, cytopenia) are usually present. (Choice C) Disseminated histoplasmosis can cause peripheral lymphadenopathy, but almost all cases are accompanied by fever, fatigue, weight loss, and laboratory abnormalities (eg, transaminase elevation, anemia of chronic disease). (Choice D) Certain drugs (eg, phenytoin) can cause painless peripheral lymphadenopathy without other symptoms. However, chlorthalidone is not a common culprit. (Choice E) Lung cancer can cause hilar and mediastinal lymphadenopathy, but chest x-ray would likely show a pulmonary mass. In addition, progressive symptoms (eg, worsened chest x-ray, weight loss, pulmonary manifestations) would be expected over the course of a year. Furthermore, spread to the inguinal lymph nodes would be atypical. Educational objective: Follicular lymphoma is a common form of non-Hodgkin lymphoma. It generally presents in an older patient with months or years of waxing and waning lymphadenopathy. B symptoms and laboratory abnormalities are rare, but mediastinal/hilar lymphadenopathy is sometimes seen.

A 62-Year-Old Man Comes to the Office Due to an Abnormal