Conjunctival CD5+ MALT lymphoma and review of literatures

摘要

We report a 35-year-old woman with multicentric CD5-positive mucosa associated lymphoid tissue (MALT) lymphoma of conjunctival region. In this case, the histologic features were typical of marginal zone/MALT lymphoma with reactive follicles, marginal zone (centrocyte-like) cells, and plasma cells. Immunohistochemically, the malignant cells expressed markers of B-cell lineage and unusually CD5 positive. Our patient treated with chemotherapy. It has thought that CD5-expression is a marker for unusual and aggressive clinical course. The occurrence of multicentric conjunctival CD5-positive MALT lymphoma in the younger age further support to the notation that CD5+ MALT-lymphomas arising in the ocular adnexa might be characterized by an unusual clinical course. Introduction Ocular adnexal lymphomas present usually as a primary disease of the orbital soft tissue, conjunctiva, and eyelid. The majority of lymphomas occurring in the ocular adnexa are B-cell non-Hodgkin lymphomas [1]. These are predominantly extranodal marginal zone B-cell lymphomas (MZL), according to the Revised European American Lymphoma (REAL) classification, but they can also include mantle-cell lymphoma (MCL) [12].Extranodal marginal zone B-cell lymphoma of mucosa associated lymphoid tissue (MALT lymphoma) histologically comprises small to medium-sized B cells. The neoplastic cells infiltrate the reactive follicles, showing follicular colonization, and have typical lymphoepithelial lesion [3].The neoplastic cells express pan B-cell antigens (CD19, CD20, CD22). Typically, they are negative for CD5, CD10, and CD23 [2]. The prognosis for ocular adnexal lymphomas is closely related to the age of patients, clinical stage at presentation, localization, blood lactate dehydrogenase values, signs and symptoms of disease, response to treatment, histologic type, and immunohistochemical markers such as MIB-1 (Ki-67) and p53 [4]. Characteristically, MZL of the MALT type affects older patients and may remain localized for years, while disseminated disease involving bone marrow and peripheral blood is rare. Localized tumors may cure with local irradiation, whereas disseminated stages of the disease are not curable and transformation into a large cell NHL may occur[2]. In recent studies, several cases of conjunctival CD5-positive MALT lymphoma have been reported [356]. In this study, we described a case of conjunctival MZL of the MALT type with an unusual clinical course, a CD5+ immunophenotype and favorable response to chemotherapy. Case History A 35-year-old Iranian woman admitted to hospital with a 7-month history of left epibulbar mass. Physical examination of the left eye revealed two pink conjunctival mass, measuring 30×15 mm, involving the palpebral conjunctiva and superior and inferior cul-de-sac. (Fig. 1A,B) The best corrected visual acuity was 20/20 in both eyes. Extraocular motility was full. The cornea, anterior chamber, iris, lens, and fundus of the left eye were normal. The right eye was completely unremarkable. The intraocular pressure was normal for the both eyes. Conventional histological examination was performed on an incisional biopsy of the conjunctival tumor. Microscopically, the tan-pink conjunctival specimen consisted of a diffuse dense lymphocytic infiltrates, which displayed an expansive growth pattern within the marginal zone, surrounding reactive follicles.These neoplastic cells were cytologically heterogeneous, consisting of small lymphocytes, centrocytelike cells, plasmacytoid cells. The tumor cells infiltrated the conjunctival epithelium with the formation of lymphoepithelial lesions. (Fig. 2A) Another feature of this tumor was “follicular colonization,” a secondary infiltration of the germinal centers by the neoplastic marginal zone B-cells. Immunohistochemically, they were characterized by positivity for CD20. The neoplastic cells were negative for CD3. CD10 had positive reactivity only in the germinal centers. General expression of CD20 revealed t