A 24-year-old woman presents to the clinic with a 2-month history of a painless, enlarging lump in her left lower neck. She also reports intermittent fevers, drenching night sweats, and an unintentional 12-lb weight loss over the same period. Past medical. History is negative, and she does not take any medications. On physical examination, there is a 3-cm, firm, non-tender, mobile left supraclavicular lymph node. A chest X-ray reveals a large anterior mediastinal mass. An excisional biopsy of the neck node is performed.
Which of the following microscopic findings is most characteristic of the suspected diagnosis?
The correct answer is:
A) Large cells with bilobed nuclei and prominent eosinophilic nucleoli
This patient is presenting with the classic features of Hodgkin lymphoma (HL). The clinical B-symptoms (fever, night sweats, weight loss) and the presence of a painless supraclavicular node and a mediastinal mass in a young adult are highly suggestive of the nodular sclerosis subtype, which is the most common form of HL. The pathognomonic finding is the Reed-Sternberg (RS) cell. These are giant, multinucleated cells (or cells with bilobed nuclei) that resemble owl's eyes due to their prominent, inclusion-like eosinophilic nucleoli. RS cells are derived from B-cells but typically lose their ability to express most B-cell surface markers. Instead, they characteristically express CD15 and CD30.
Answer choice B: Neoplastic cells in a follicular pattern with cleaved nuclei, is incorrect. This describes follicular lymphoma, which involves the t(14;18) translocation and overexpression of Bcl-2.
Answer choice C: Proliferation of small lymphocytes and smudge cells, is incorrect. This is the hallmark of chronic lymphocytic leukemia (CLL), which presents with a significant peripheral lymphocytosis, unlike the localized lymphadenopathy typical of early Hodgkin lymphoma.
Answer choice D: Sheets of intermediate-sized B-cells with high mitotic index, is incorrect. This is more typical of diffuse large B-Cell lymphoma (DLBCL), which is the most common non-Hodgkin lymphoma and tends to present in older adults.
Answer choice E: Small, mature lymphocytes in a “starry sky" pattern, is incorrect. This describes Burkitt lymphoma, where tingible body macrophages (the "stars") are interspersed among a dense sea of malignant B-cells (the "sky"). It is associated with the t(8;14) translocation.
Key Learning Point
Hodgkin lymphoma follows a bimodal age distribution (peaks at age 20 and age 65). It typically presents with painless lymphadenopathy that spreads in a contiguous fashion (nodal chain to nodal chain). The diagnosis requires the identification of Reed-Sternberg cells (CD15+, CD30+) within a background of non-neoplastic inflammatory cells.
