Despite primary extranodal invasive lymphoma of the ovary is a rare disease, ovarian lymphoma is typically secondary to diffuse systemic disorder. In extranodal lymphoma, primary ovarian lymphoma accounts for 0.5% of extranodal non-Hodgkin’s lymphoma and 1% of all ovarian tumors . Several perspectives regarding the origin of primary ovarian lymphoma have been documented currently as the following: 1. Primary ovarian lymphoma originates from the lymphoid tissues that already exist in the ovary; 2. The blood vessels around the hilum of the ovary or the corpus luteum cells may be tumor-derived cells; 3. Reactive lymphocytes may be secondary to ovarian inflammation (pelvic inflammatory disease and endometriosis) or autoimmune diseases, and following processes of malignant transformation into ovarian primary lymphoma .
L.R. Weekes first discovered primary bilateral ovarian Burkitt lymphoma in a 15-year-old girl from Guatemala in 1986. To our knowledge, only 26 cases of primary ovarian Burkitt lymphoma have been reported in the literature. Among the described cases, 15 of them were bilateral and 10 were unilateral (1 unavailable). The age of the patients ranged from 6 to 62 years (average, 27 years old). The clinical manifestations of ovarian primary Burkitt lymphoma are unique from one another . Most patients complained of abnormal pain accompanied by additional symptoms included fever, abnormal mass, lower abdominal swelling, ascites, and vaginal bleeding [39; 40]. As for our patient, the young married woman was diagnosed with a mass in the right ovary by physical examination due to infertility. The grossly ovarian mass was well-circumscribed and encapsulated. The tumor was measured at approximately 11×11×5 cm in size. The section surface of the tumor presented tender, gray-white in color with some scattered bleeding spots. The histological findings of the present case were identical to Burkitt’s lymphoma that occurred in other organs, which were characterized by diffuse growth of medium-sized lymphoid cells with round nuclei and agglomerated chromatin . Necrotic debris could be seen in the background, which was swallowed by many tissue cells, forming a typical pattern of the "starry sky”. Among the reported cases, 6 were FIGO (International Federation of Gynecology and Obstetrics) staging 1A, 1 was FIGO staging 1B, 2 were FIGO staging 2A, and 11 were FIGO staging 4A (6 unavailable). This case presented a primary ovarian Burkitt lymphoma of FIGO staging 1A.
Primary ovarian Burkitt lymphoma originates from B cells and expresses B cell markers such as CD20, CD22, CD19, and CD10. Cytokeratin and T cell markers are negative. MYC represents a family of regulator gene and proto-oncogene that codes for transcription factors. The MYC family consists of three related human genes c-myc (MYC), l-myc (MYCL), and n-myc (MYCN). c-myc (also sometimes referred to as MYC) is the first gene discovered in this family due to its homology with a viral gene v-myc. In cancer, c-myc is often expressed constitutively (persistently), which leads to an increase in the expression of multiple genes. Additionally, some of them are even involved in cell proliferation and contribute to the formation of cancer cells. Common human translocations involving c-myc are critical to the development of most Burkitt lymphomas [13; 42], and the mutation is usually t (8;14) (q24; q32) translocation. In this case, CD20 was strongly positive, the result of fluorescence in situ hybridization (FISH) was MYC (8q24) rearrangement, and the morphology combined with immunohistochemical results and molecular pathological features were consistent with the diagnosis of Burkitt lymphoma.
The differential diagnosis of primary ovarian Burkitt lymphoma includes secondary ovarian lymphoma, adult granular cell tumor of the ovary, and small cell neuroendocrine carcinoma (SCNEC). Fox et al. proposed the diagnostic criteria for primary ovarian lymphoma in 1988 included 1. Lymphoma should be confined to the ovary or adjacent lymph nodes or structures at the time of diagnosis; 2. There is no evidence showing the presence of blood or bone marrow disease; 3. Distal involvement should occur at least a few months after ovarian involvement . Adult granular cell tumor of the ovary is frequently encountered in postmenopausal women, with the peak age of onset at 50–55 years old, which represents the most typical clinical ovarian tumor-related to estrogen secretion. The nucleus is round, oval, or polygonal, lightly stained, less cytoplasm, and the nuclear groove is visible. Immunohistochemical expression of sex cord-stromal markers such as α-inhibin, calretinin, FOXL2, and CD99. The epithelium marker is negative. Differential diagnosis of the disease also requires an accurate determination of SCNEC. SCNEC is a high-grade carcinoma composed of small to medium-sized cells with scant cytoplasm and neuroendocrine differentiation. The cytoplasm of the tumor is sparse with a small cell nucleus. Single small nucleolus can be visible and mitotic images are common. Tumor cells can be a nested pattern, string-shaped and irregular cell clusters, and express neuroendocrine markers such as CgA, Syn, and CD56.
As Burkitt lymphoma is an aggressive B-cell non-Hodgkin's lymphoma with a short and active proliferation cycle, multi-drug combination chemotherapy is considered as an optimal treatment protocol for patients with Burkitt lymphoma . The 26 cases previously reported were mostly treated with surgery followed by chemotherapy (17/26). Surgical treatment plays an important role in providing clinical information, staging, and diagnosis, and patients who confirmed diagnosis should start chemotherapy as early as possible. Although Burkitt lymphoma is highly malignant, combined treatment with multiple chemotherapy regimens can substantially improve the survival rate of Burkitt lymphoma patients . The follow-ups ranged from 0.5 to 3.5 years (average1.6 years). Four death cases were reported at an overall survival rate of 15/19 (78.95%) (7 unavailable). In our case, the patient underwent right salpingo-oophorectomy and accepted eight cycles of CODOX-M/IVAC combined with HyperCVAD chemotherapy after surgery. The patient developed no relevant disease 10 months following the completion of the therapy.