LYMPHOMA

Q) An 18-year-old boy presents with cough, chest pain, and low-grade nightly fevers of severalweeks duration. He has a 4-year history of smoking two packs of cigarettes per day. Chest x-ray reveals a large mass in the mediastinumwith extension into the right upper chest. Which of the following is the most likely diagnosis?
(A) adenocarcinoma
(B) squamous cell carcinoma
(C) small cell carcinoma
(D) lymphoma
(E) metastatic Wilms tumo

Ans: D.

The differences between adults and children are frequently emphasized in medical training.

The differences between adults and adolescents should also be recognized. The differential diagnosis for many conditions, such as an intrathoracic mass seen in this case, is age dependent. While carcinoma of the lung is a leading cause of intrathoracic mass in adults, it is very rare in adolescents, even those who have a significant smoking history. That eliminates choices (A), (B), and (C). While it is true that Wilms tumor frequently metastasizes to the lung, this malignancy almost always presents in the first few years of age and would be unheard of in an 18-year-old. That leaves lymphoma as the only remaining choice and the most likely diagnosis. (D) is the correct answer. Other causes, such as tuberculosis, histoplasmosis, and sarcoid need to be considered but were not listed as choices