Primary extranodal marginal zone B-cell lymphoma of the ovary, fallopian tube, and uterus: A rare case report and review of the literature

BACKGROUND: Extranodal marginal zone lymphoma (EMZL) is a type of low-grade B-cell lymphoma that most commonly occurs in gastric tissue. To our knowledge, only five cases have been documented noting primary EMZL of the fallopian tube and only one case involving the ovary. We describe a rare case of extranodal marginal zone B-cell lymphoma, involving the left fallopian tube, left ovary, uterus, and left pelvic sentinel lymph node. CASE PRESENTATION: A 78-year-old female presented to her gynecologist due to worsening of vulvar pain. A transvaginal ultrasound revealed a left adnexal tubular mass. The patient had a total robotic hysterectomy and bilateral salpingo-oophorectomy. Intraoperative frozen section of the left fallopian tube mass showed a small blue cell tumor, favoring lymphoma. Histologic sections of the ovary revealed effacement of the architecture by a diffuse atypical lymphoid infiltrate composed predominately of small CD20(+) B-lymphocytes, including few with pale cytoplasm. Similar findings were noted in the endometrium, myometrium, serosa, left fallopian tube and ovary, and left pelvic sentinel lymph node. Molecular testing was positive for MYD88 mutation but negative for CXCR4 mutation. Differential diagnosis included EMZL and lymphoplasmacytic lymphoma; however, given the absence of IgM paraprotein/monoclonal protein, a diagnosis of EMZL was favored. The patient was managed with surveillance; positron emission tomography scan was negative for recurrence at one year. CONCLUSION: Although EMZL of the ovary and fallopian tube is rare, it should be maintained on the differential diagnosis if atypical lymphoid cells or dense lymphoid aggregates are observed in the surgical specimen.