A Case Report of an Unusual Cause of Abnormal Uterine Bleeding: Primary Cervical Lymphoma Misdiagnosed As Hormonal Dysfunction

Primary cervical lymphoma is an exceptionally rare malignancy that may mimic abnormal uterine bleeding (AUB) of endocrine origin, particularly when cervical cancer screening tests and initial imaging studies are normal. Because AUB is the primary manifestation of cervical lymphoma, its diagnosis can be highly challenging. This symptom is frequently shared with prevalent gynecological conditions such as polyps, adenomyosis, leiomyomas, malignancy, and ovulatory dysfunction. When a patient presents with AUB alongside negative screening tests, clinical reasoning is usually directed toward non-structural causes of AUB, delaying the diagnosis of rare lymphoid malignancies that arise deep within the cervical stroma while sparing the superficial epithelium. We present an unusual case of a 44-year-old G2P2 woman with persistent AUB. Initial evaluation, including transvaginal ultrasonography and Papanicolaou testing, was unremarkable, leading to a presumptive diagnosis of ovulatory dysfunction. Given the persistence of symptoms, a follow-up pelvic MRI was performed, revealing an 8.5 x 6.7 x 5.1 cm expansive cervical mass, raising suspicion for advanced squamous cell carcinoma. The diagnosis of primary cervical lymphoma was only confirmed through histopathological and immunohistochemical analysis, which revealed a diffuse large B-cell lymphoma. The proposed treatment consisted of six cycles of chemotherapy according to the R-CHOP protocol (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). Despite its extreme rarity, primary cervical lymphoma must be included in the differential diagnosis of persistent AUB, especially when conventional cervical cancer screenings and imaging studies are negative. Although many specialists may never encounter this malignancy during their careers, a delayed diagnosis can postpone essential treatment and significantly compromise patient prognosis.