Myeloproliferative neoplasms are associated with lymphoproliferative diseases following the administration of cytotoxic drugs or exposure to radiation, but are rare prior to therapy. The present study reports the case of a 61-year-old female with a history of transient ischemic attack. The patient, who presented with a palpable mass in the epitrochlear area of the left arm, was simultaneously diagnosed with follicular lymphoma and an unclassifiable myeloproliferative neoplasm. Excisional lymph node biopsy revealed stage I follicular lymphoma (grade 1). Laboratory findings demonstrated leukocytosis, erythrocytosis, thrombocytosis and decreased erythropoietin. Biopsy of the bone marrow revealed hypercellularity, with predominance of erythroid cells, and large polylobated megakaryocytes with increased mitotic figures, but no evidence of lymphomatous infiltration. The janus kinase 2 V617F mutation was also detected in the cells derived from the bone marrow specimen. Following local excision of the lymph node in the left epitrochlear area, radiation was delivered to the involved field, at a dose of 24 Gy in 12 fractions. The patient was started on hydroxyurea (1 g twice per day, orally) 2 weeks subsequent to radiotherapy, and was administered 500 mg twice per day as maintenance therapy. At the six-month follow-up, the white blood cell count, hemoglobin levels and platelet count had reduced, and the patient was in a healthy condition. A computed tomography scan of the neck, chest and abdomen indicated no abnormalities. To the best of our knowledge, the present study is the first case report of follicular lymphoma coexisting with an unclassifiable myeloproliferative neoplasm in a previously healthy patient. Molecular and genetic studies are required to further evaluate this infrequent disease association.