Behind the bleeding: rare and relentless uterine lymphoma ending in chemotherapy toxicity

A woman in her 30s presented with irregular vaginal bleeding and abdominal distension. Initial imaging suggested a uterine fibroid; however, intraoperative findings during planned laparotomy were atypical, prompting an excisional biopsy. The initial pathological diagnosis was endometrial stromal sarcoma, and staging imaging suggested liver metastases, prompting chemotherapy initiation. One month later, she developed urinary retention, oedema and dyspnoea. Imaging revealed a large pelvic mass causing bilateral hydronephrosis, extensive lymphadenopathy and tumour lysis syndrome, managed with stents and supportive care. Re-evaluation of the biopsy established the diagnosis of primary endometrial diffuse large B-cell lymphoma (DLBCL). Hepatitis B positivity delayed chemotherapy; interim dexamethasone provided relief. Intensive chemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine and methotrexate/ifosfamide, etoposide and cytarabine resulted in a rapid response but was complicated by neutropenic sepsis, leading to death. This case highlights the diagnostic challenge of endometrial DLBCL, the critical importance of pathological re-evaluation and the need for careful toxicity monitoring during intensive chemotherapy.