Overt to covert follicular lymphoma

A 32-year-old female was found to have an elevated lymphocyte count and referred to haematology. Initially she presented to her GP in 2018 with fatigue and dizziness. The symptoms had fully resolved by the time she was reviewed in haematology. Haemoglobin 133 g/l, White cell count 25 10 9 /L, Plt 256 10 9 /L, Lymph 18.5 10 9 /L. Flow cytometry revealed a lambda restricted CD5-ve, CD10+ve, Cd20+ve, CD79b+ve, FMC7+ve B cell clone. Cytogenetics found the presence of the t(14:18). Bone marrow biopsy was performed and demontrated 20% lymphocytes with the same immunophenotype as PB flow cytometry. CT chest, abdomen and pelvis showed widespread low volume lymphadenopathy. Core biopsy of axillary LN confirmed the diagnosis of Follicular Lymphoma. This patient had no indications for treatment and was observed. Interestingly the lymph nodes regressed and lymphocytosis fully resolved over 2 years. Up to 25% of the general population carry t(14:18) in a proportion of their lymphocytes. Very few develop follicular lymphoma and therefore this condition remains on a very diverse spectrum. This case demonstrates the body's ability to regain control of this clone to a subclinical level. This patient with subclinical follicular lymphoma remains well and under observation.