A 42-year-old previously healthy woman comes to the office due to fever and sore throat. She has no cough. Physical examination shows tonsillar exudate and a nontender cervical lymph node that measures 3.5 cm in diameter. Oral antibiotic therapy is started and on a follow-up visit a week later, the patient reports that her symptoms have resolved. The previously enlarged cervical lymph node has decreased slightly in size. On several follow-up visits over the following year, the patient remains asymptomatic and the size of the lymph node fluctuates but does not disappear completely. Referral to a surgeon is made and excisional biopsy of the lymph node is performed. Which of the following is the most likely diagnosis?
This patient with persistent fluctuating lymphadenopathy, who may have had an unrelated pharyngitis (treated with antibiotics) on initial presentation, most likely has follicular lymphoma. Follicular lymphoma is the most common indolent non-Hodgkin lymphoma (NHL) in adults and the second most common NHL overall (after diffuse Large B cell lymphoma). It derives from germinal center B cells and typically has a long, waxing and waning clinical course.
The condition most often presents in middle-aged patients with painless lymph node enlargement or abdominal discomfort from an abdominal mass. Histology is notable for a nodular pattern, and the neoplastic follicles are composed of a mixture of centrocytes (cleaved cells) and centroblasts (noncleaved cells). The majority of tumors exhibit a t(14;18) translocation, resulting in overexpression of the BCL2 oncogene that blocks programmed cell death.
(Choice A) Acute lymphoblastic leukemia/lymphoma is the most common malignancy in children. It presents with lymphadenopathy, hepatosplenomegaly, fever, bleeding, and bone pain. Neoplastic cells are pre-B or pre-T cells (lymphoblasts).
(Choice B) Burkitt lymphoma is a highly aggressive (but generally chemotherapy-responsive) B-cell NHL associated with chronic Epstein-Barr virus infection and/or deregulation of the MYC proto-oncogene. Patients typically develop rapidly growing tumor masses in the facial bones, jaw, or abdomen. Tumor doubling time is very rapid and spontaneous tumor lysis can occur.
(Choice C) Diffuse large B-cell lymphoma typically presents with a rapidly enlarging nodal (neck, abdomen, mediastinum) or extranodal symptomatic mass. The Waldeyer's ring (oropharyngeal lymphoid tissue) and gastrointestinal tract are commonly involved, and systemic "B" symptoms (fever, weight loss, drenching night sweats) can also be seen.
(Choice E) Hairy cell leukemia, a mature B-cell neoplasm, presents with splenomegaly and pancytopenia most often in older men. Lymph node enlargement is not characteristic. Leukemic cells have hairlike cytoplasmic projections and are positive for tartrate-resistant acid phosphatase (TRAP).
(Choice F) Mycosis fungoides is a cutaneous T-cell lymphoma. Proliferating CD4+ atypical lymphocytes infiltrate the dermis and epidermis, where they form Pautrier microabscesses. This condition manifests with plaques (often on trunk or buttocks) that may be confused with eczema or psoriasis. Generalized erythema and scaling and thickening of the skin (erythroderma) may result.
Educational objective:
Follicular lymphoma is the most common indolent non-Hodgkin lymphoma in adults. It is of B-cell origin and presents with painless waxing and waning (ie, fluctuating) lymphadenopathy. The cytogenetic change t(14;18) is characteristic and results in overexpression of the BCL2 oncogene.