A 67-year-old female patient underwent partial gastrectomy for gastric cancer in November 2007, determined to be complete cure and under the follow up observation without special symptoms and findings, and in pelvic computed tomography (CT) performed during the follow up observation, a mass suspicious to be either uterine sarcoma or uterine cervical cancer in the uterine cervix as well as the uterine body was detected, and thus transferred to our department of gynecologic oncology.

At the time of admission, blood pressure was 100/70, pulse was 72, temperature was 36.5℃, and general condition was good, and in pelvic examination, a mass and the erosion of the uterine cervix were not detected macroscopically.

In blood test, hemoglobin was 11.2 g/dL, red blood cell volume was 31.4%, leukocyte was 4,800/mm³, platelet was 229,000/mm³, and they were within normal ranges, and in urine test, protein was detected, nonetheless, glucose was not detected. In addition, in biochemistry test, abnormal results were not reported. The tumor marker Ca 72-4 was 1.08 and CA 19-9 was 5.63, which were normal, and in addition, CA-125 was 6.7, and normal results were shown. In Papanicolaou test (PAP test) performed but special results were not shown.

In pelvic computed tomography a lobular shape mass of 7.6×6.5 cm in size showing heterogeneous contrast enhancement was detected (Fig. 1) in the vicinity of the uterine cervix, and other than that, recurrence or other special findings in the stomach resection area was not detected. And in positron emission tomography-computed tomography a mass approximately 8.5 cm in size with increased F-18 fluorodeoxyglucose intake was observed in the uterine cervical area, and it was speculated to be either uterine cervical cancer or uterine sarcoma showing a fast growing pattern (Fig. 2).

The trend of the incidence of NHL is on the continuous increase since the 1930s, and the incidence of average 3.5 cases in 100,000 individuals annually in 1935-1939 was increased to average 20 cases in 100,000 individuals annually in 1990-1994 [3]. Such increase could be considered to reflect the improvement of diagnostic method and histological diagnosis rather than the increase of the incidence. 30% of NHL occur in tissues other than lymph nodes, which is referred to as extranodal lymphoma, and in ¼ of the most prevalent subtype of NHL diffuse large B cell lymphoma (DLBCL), it occurs as extranodal primary lymphoma [4]. The cases developing lymphoma as the secondary lesion in the female reproductive system are approximately 40%, nonetheless the cases developing as a primary lesion is very rare, and tumors originated from the ovary account for 49%, originated from the uterus are 29%, and originated from the oviduct account for approximately 11% [5,6]. For the diagnosis of primary lymphoma developed in the female reproductive system, it has to be diagnosed first that tumors show the pattern restricted to the uterus, it has to be evaluated comprehensively that the evidence of disease is absent in organs other than the uterus, and the evidence of leukemia should be absent in blood tests [7]. In cases developed primary lymphoma in the uterus, vaginal hemorrhage is presented with most frequently, and in addition, non-specific pelvic pain, vaginal hemorrhage after intercourse, dyspareunia, etc. may be presented with, and as in our case, gynecological symptoms are absent in some cases. Nevertheless, the B symptoms showing in systemic lymphoma, such as high fever, night sweating, and weight loss do not manifest frequently [8]. Uterine primary lymphoma requires the differential diagnosis from inflammatory diseases, and malignant diseases such as uterine cervical cancer, cancer in the uterine body, and uterine sarcoma, and for its accurate diagnosis, histopathological test as well as immunohistochemical test are prerequisite [6,9]. Particularly, lymphomas developed in the uterine cervix are originated from the uterine cervical parenchyma and located below the epithelium, and the squamous cell layer above them is maintained intact, and thus it is a difficult task to detect lymphoma by PAP test [10].

Upon the diagnosis of lymphoma by histological test, the differential diagnosis for the cell type of the origin of lymphoma is performed, and the final diagnosis is made by performing the staining for B cell and T cell specific markers such as CD 20, CD 79a, CD 45RO, and CD 3. In our case, the positive reaction to CD 20 and CD 79a was shown and the negative reaction to CD 45RO and CD 3 was shown, and thus it was able to be diagnosed as lymphoma originated from B cells. The primary lymphoma developed in the female reproductive system is very rare, and thus the treatment protocol has not been established, and according to reports, surgery, chemotherapy, and radiation therapy alone, the combination with postoperative adjuvant chemotherapy, the simultaneous treatment of chemotherapy and radiation therapy, etc. have been attempted [8,10]. Based on recently reported studies, the anti-CD-20 immunochemotherapy the R-CHOP regimen has been administered as the effective standard therapy [11,12]. Rituximab is the monoclonal antibody used for the treatment of B cell lymphoma for the first time, and because of its clinical effectiveness and little drug side effects, it has been established as a treatment regimen [11].

Primary malignant lymphoma in the uterus is very rare, and the symptoms as well as syndromes are non-specific, and thus its diagnosis as well as treatments has not been established. Therefore, in the future, through continuous clinical discussion on this disease, a guideline for the diagnosis and treatment for primary uterine lymphoma should be established.