Primary central nervous system extranodal nasal-type natural killer/T-cell lymphoma with CD20 expression

Primary central nervous system extranodal NK/T-cell lymphoma, nasal type with CD20 expression: Case report and review of the literature

Primary central nervous system (PCNS) extranodal NK/T-cell lymphoma, nasal type (ENKTCL), is an exceedingly rare tumor. To the best of our knowledge, only 27 cases and only one reported aberrant CD20 expression have been documented in the literature. Here we present a second case of PCNS ENKTCL with aberrant CD20 expression in a 43-year-old immunocompetent Chinese female. The patient presented with tremors, weakness in the right upper limb, and a slow reaction. Magnetic resonance imaging revealed multiple brain lesions. A histological examination revealed a diffuse distribution of intermediate-sized pleomorphic lymphocytes with angiocentric growth. The tumor cells expressed CD2, CD3, CD56, T-cell intracellular antigen-1, granzyme B, and Epstein-Barr virus-encoded RNAs (EBERs), with additional partial and weak CD20 and CD30 expression. Despite a confirmatory pathological diagnosis, the patient refused treatment and was discharged, ultimately dying from the disease. In the literature review, the clinical, immunohistochemical, EBERs, treatment, and prognostic features of PCNS ENKTCL were summarized. Although PCNS ENKTCT is extremely rare, it does occur and should always be included in differential diagnoses. CD20 expression should be evaluated routinely with relevant markers. The accumulation of cases is crucial for developing an effective treatment strategy for this rare and aggressive malignancy.

Extranodal nasal-type NK/T-cell lymphoma with CD20 positive: A case report and review of literature

ABSTRACT

Extranodal nasal-type natural killer (NK)/T-cell lymphoma is a type of non-Hodgkin lymphoma. Neoplastic lymphocytes are positive for CD4, CD56, and CD20, a specific B-cell marker. CD20 positive NK/T-cell lymphoma is rare, with only nine reported cases. This paper reports a case of nasal-type NK/T-cell lymphoma with CD20 positivity in a 47-year-old woman. The patient presented with bilateral nasal congestion and bloody nasal cavity secretions for 2 months. Computed tomography revealed thickening of the nasal mucosa and posterior wall of the nasopharyngeal crest, and the left and right cervical lymph nodes were enlarged. On histopathology, the lesion was composed of medium-sized atypical lymphoid cells and vascular infringement. Immunohistochemical staining showed that the tumor cells were positive for CD20, CD3, CD56, and Epstein-Barr virus (EBV)-encoded RNA in situ hybridization. The patient was treated with radiotherapy for 2 months and is currently well.

Successful Treatment of Primary CNS Extranodal NK/T-Cell Lymphoma with Surgery and Chemotherapy Combined with Sintilimab: A Case Report and Literature Review

Primary central nervous system extranodal natural killer/T-cell lymphoma (PCNS ENK/TCL) is an extremely rare lymphoma. Only 23 cases of PCNS ENK/TCL have been reported in the English literature. Due to the rarity of this lymphoma, an effective therapeutic strategy has not been defined. Generally, this type of lymphoma is treated with surgery, intrathecal chemotherapy, and postoperative chemoradiation therapy. The prognosis is poor. Herein, we present a case of primary brain NK/T cell lymphoma in a 50-year-old immunocompetent Chinese female and review the literature. The patient underwent intracranial tumor resection and was subsequently treated with a PD1 monoclonal antibody (Sintilimab) combined with chemotherapy. The patient survived 15 months after diagnosis. This is the first report of PCNS ENK/TCL treated with surgery and chemotherapy combined with immunotherapy and suggests an effective treatment regimen for PCNS ENK/TCL.

Clinical analysis of patients with primary and secondary extranodal natural killer/T-cell lymphoma of central nervous system

Extranodal natural killer (NK)/T-cell lymphoma (NKTL) is a rare non-Hodgkin lymphoma that rarely arise exclusively in or metastasizes to the central nervous system (CNS). Globally, CNS involvement of NKTL heralds a serious prognosis and there is no standard treatment. 19 of 414 patients (4.59%) with ENKL followed were diagnosed with CNS involvement between 2006 and 2020. Two patients had primary CNS (PCNS) NKTL, and 17 patients had secondary CNS (SCNS) invasion. A total of 9 patients survived and 10 patients died. The median overall survival time was 55 months, and the median survival time after CNS invasion was 17 months. The 5-year cumulative survival probability was 45.7%. In conclusion, CNS risk evaluation and prophylaxis treatment can be carried out for patients with NK/T-cell lymphoma prognostic index risk group III/IV. In terms of treatment, systemic therapy based on methotrexate combined with radiotherapy and intrathecal chemotherapy can be selected.

An Unusual Case of EBV-Negative Primary CNS Lymphoma of Natural Killer/T-Cell Lineage

Extranodal NK/T-cell lymphoma (ENKTL) is a well-defined cytotoxic lymphoma strongly associated with Epstein–Barr virus (EBV) infection, commonly affecting the nasopharynx and upper aerodigestive tract. Primary central nervous system (CNS) involvement is rare, and only 17 cases were previously reported in the literature. Here, we report the case of a 44-year-old male admitted with a 3-month history of personality changes and progressive right leg weakness. Brain magnetic resonance imaging studies (MRIs) revealed multiple rim-enhancing brain lesions bilaterally. An extensive clinical and laboratory workup was unrevealing, and 2 brain biopsies were initially considered inconclusive. Pertinently, no systemic lymphoproliferative disorder was identified. The patient initially experienced remarkable clinical improvement with dexamethasone, pulse methylprednisolone, and rituximab therapy. However, he eventually had rapid clinical deterioration, was found to have increased brain lesions, and died nearly 6 months after the initial presentation. During this time, the second brain biopsy was found to show involvement by T-cell lymphoma of NK-cell lineage, which was EBV negative. No post-mortem examination was done to identify any systemic lymphoma. This case serves to expand the spectrum of lymphomas involving the CNS.

CD20-positive extranodal NK/T cell lymphoma: clinicopathologic and prognostic features

Extranodal natural killer (NK)/T cell lymphoma (ENKTCL) with aberrant CD20 expression is extremely rare. Here, we describe the clinicopathologic features of 11 CD20-positive ENKTCLs from three institutions in China along with a literature review. Membranous expression of CD20 was identified in 1.29% (11/851) of ENKTCLs. CD20-positive ENKTCLs primarily occurred in extra-nasal sites (72.2%, 13/18) rather than in the nasal cavity (27.8%, 5/18). Most evaluated patients (71.4%, 10/14) presented ENKTCL at advanced stage IV. The percentage of CD20-positive tumor cells ranged from 20 to 90%, and the CD20 staining intensity was dimmer in tumor cells than in normal B cells. Among four cases with multiple biopsies, three cases showed discordant expression of CD20 between the disseminated and primary lesions. All evaluated cases were negative for other B cell markers, including PAX5, CD79a, and CD19, except for one case that showed focally positive for CD79a. Patients with CD20-positive ENKTCL more frequently had advanced diseases (stage III/IV: 70% vs 17%, p = 0.001), with older age (median age at diagnosis: 60 years vs. 43.5 years, p = 0.006) and had inferior outcome (median survival: 18.7 moths vs 36.0 moths, p = 0.017) compared with CD20-negative cases. Four nonsynonymous single nucleotide variants (C > T) and one stop-gain mutation (C > T) in the exonic region of CD20 gene (MS4A1) were detected in one of seven cases with target region next-generation sequencing. Thus, ENKTCL with aberrant CD20 expression is rare, tends to occur in older patients, and is characterized by a highly aggressive clinical course and poor outcomes. The mechanism underlying the expression of CD20 in ENKTC still remains unknown.

De Novo Testicular Extranodal NK/T-Cell Lymphoma: A Clinicopathologic Study of 21 Cases With Review of Additional 18 Cases in the Literature

Although the testis is not uncommonly involved during the course of disease in both nasal and non-nasal extranodal NK/T-cell lymphoma (ENKTCL), only a few cases presenting initially with a testicular mass have been previously reported. These have been documented as case reports, rather than as study series. Because of its rarity, the clinicopathologic features and the prognosis of de novo testicular ENKTCL have not been well characterized. Clinicopathologic features of 21 cases of de novo testicular ENKTCL from 3 institutions in China were retrospectively analyzed with review of an additional 18 cases from the literature. De novo testicular ENKTCL accounted for 0.72% (21/2906) of all ENKTCL during the study period. The median age of patients with de novo testicular ENKTCL was 45 years (range, 21 to 79 y). Most (90.9%) cases occurred in Asians. All patients initially presented with testicular swelling and most (91.9%) had unilateral testicular masses. The majority (73.0%) of patients presented at Ann Arbor stage I/II. Expression of CD56 was found in 92.1% (35/38) of the available cases. Interestingly, aberrant expression of CD20 was found in the tumor cells in 10.3% (4/39) of cases. The majority of patients with follow-up data (24/30, 80%) had extratesticular involvement during the follow-up period (median follow-up, 6 months; range, 0.5 to 87 mo). Preferential sites of extratesticular involvement included lymph nodes, skin, contralateral testis, bone marrow, spleen, adrenal gland, and central nervous system. Of the 30 patients with survival data, 70% (22/30) of patients died of the disease. The 2-year overall survival of patients with de novo testicular ENKTCL was 23%, and the median survival was 9.5 months. Patients that presented with B symptoms showed a trend toward inferior overall survival (P=0.095). No statistical significance was found between patients with stage I/II and stage III/IV (P=0.783). De novo testicular ENKTCL tends to disseminate early, shows extremely poor outcome, and should be recognized as a highly aggressive form of ENKTCL. A portion of cases show aberrant expression of CD20, and accurate diagnosis as well as timely and optimal treatment are very important.