Primary uterine DLBCL is a rare disease, and is the least common of all female genital tract DLBCL [1, 4, 5]. When DLBCL is found in the uterus, some reports have described it to be confined to the interior of a uterine leiomyoma, making diagnosis challenging due to limitation in tissue sampling [8, 9]. While endometrial biopsy can be used for diagnosis of primary uterine lymphoma, with limitations as seen in our case, image-guided biopsy is not recommended due to the risk of incorrectly staging a more common ovarian malignancy . Staging of primary uterine DLBCL is often performed by fluorodeoxyglucose positron emission tomography (FDG-PET)/CT due to uterine lymphomas showing increased FDG above physiologic endometrial uptake [2, 3].
As highlighted in our case, surgical intervention was required for diagnosis of disease given the insufficient and non-diagnostic endometrial biopsy. However, there is no standardization regarding surgical versus nonsurgical management. There is standardization on treatment regimen, and R-CHOP chemotherapy is considered to be the most accepted and effective regimen . Many of the documented reports of primary uterine and female genital tract DLBCL, including our own, show typical CD20 + markers . This allows for successful R-CHOP treatment with a five year OS and CSS of 70.2% and 75.2%, and multiple reports of remission [1, 11]. More recently, a randomized phase 2 trial by Nowakowski et al concluded that the addition of Lenalidomide to R-CHOP (R2CHOP) improved progression free survival in newly diagnosed DLBCL .
While primary uterine lymphoma usually presents clinically with nonspecific symptoms, post-menopausal uterine bleeding is commonly reported [1, 4, 11]. Other common symptoms include back pain and clinical exam finding of pelvic or abdominal mass [3, 5]. Although uncommon, hydronephrosis is a documented symptom and presentation of DLBCL of the uterus, cervix, and ovaries. Since hydronephrosis is more often encountered in primary bladder or ureteral malignancy and in squamous cell carcinomas of the gynecologic tract, misdiagnosis or delayed diagnosis of primary DLBCL of the uterus can occur [6, 13], making heightened clinical suspicion a priority. The reported cases of hydronephrosis in the literature describe utilization of percutaneous nephrostomy tubes in place of ureteric stents due to tumor extension to the pelvic sidewalls, as was evident in our case . Additionally, other reports describe similar anatomic and pathologic findings as our patient, in which the DLBCL originating in the uterus or uterine cervix had such extensive local invasion that the anatomic boundaries between the uterus, adnexa, bladder, rectum, and inferior vaginal wall were compromised, leading to incompletely resected disease [3, 15]. Our case, and others, highlight the benefit of surgical resection for diagnosis of disease with demonstration of successful response to medical therapy and clinical remission even with residual disease at time of surgical resection.