Extranodal NK/T-cell lymphoma, nasal type: a report of 73 cases at MD Anderson Cancer Center

Characteristics, Prognostic Factors, and Survival of Patients with NK/T-Cell Lymphoma of Non-upper Aerodigestive Tract: A 17-Year Single-Center Experience

Purpose

The extranodal natural killer (NK)/T-cell lymphoma (NKTCL) of non-upper aerodigestive tract (NUAT) was found to have clinical heterogeneity compared with NKTCL of the upper aerodigestive tract (UAT) in small scale studies. We conducted this study in a much larger cohort to analyze the clinical characteristics, prognostic factors, treatment modality, and clinical outcomes of patients with NUAT-NKTCL.

Materials and Methods

From January 2001 to December 2017, a total of 757 NKTCL patients were identified and included in this study, including 92 NUAT-NKTCL patients (12.2%) and 665 UAT-NKTCLpatients (87.8%).

Results

NUAT-NKTCL patients had relatively poorer performance status, more unfavorable prognostic factors, and more advanced stage, compared with UAT-NKTCL patients. The 5-year overall survival (OS) was 34.7% for NUAT-NKTCL, which was significantly worse than UAT-NKTCL (64.2%, p<0.001). The median OS duration was 30.9 months for NUAT-NKTCL. Multivariate analysis showed that presence with B symptoms and elevated serum lactate dehydrogenase independently predicted worse OS. International prognostic index score and prognostic index of natural killer lymphoma score still had prognostic values in NUAT-NKTCL, while the Ann Arbor system could not accurately predict the OS.

Conclusion

NUAT-NKTCL is a distinctive subtype of NKTCL in many aspects. Patients with NUAT-NKTCL have relatively poorer performance status, more unfavorable prognostic factors, more advanced stage, and poorer prognosis.

Extranodal NK/T-Cell Lymphoma, Nasal Type in Guatemala: An 86-Case Series Emphasizing Clinical Presentation and Microscopic Characteristics

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT) is a lymphoid malignancy that mainly affects the nasopharynx and is associated with the Epstein-Barr virus (EBV). Increased incidence is seen in some Latin American and Asian countries. In this study, we describe a case series of 86 Guatemalan patients with ENKTCL-NT from a single diagnostic head and neck center. We emphasize the distinctive clinical, microscopic, and immunohistochemical (IHC) features, as well as EBV positivity by in situ hybridization (ISH). Most of the patients (90.6%) were of Mayan descent and low socioeconomic status (SES). Males were more often affected than females, comprising 68.3% of cases. Patient age ranged from 8 to 71, with a mean of 34.7 years. All cases arose in the upper aerodigestive tract and mainly presented as a rapidly progressive, necrotizing midfacial process affecting the nasal, nasopharyngeal, sinonasal, palatal, and oropharyngeal structures. Microscopically, ENKTCL-NT showed a diffuse polymorphic and atypical lymphoid infiltrate. Angiocentric and angiodestructive growth patterns were present with associated necrosis. Peripheral hyaline necrosis of blood vessels was a histologic hallmark. The ISH and IHC profiles included positivity of EBV, LCA, CD3, CD45RO, CD30 (focal in 39.2%), granzyme-B, TIA-1, perforin (in 82.3%), and CD56 (in 83.7%). CD20 was negative, and the Ki-67 index ranged from 70 to 90%. In Guatemala, this lymphoma is strongly associated with people of low SES and indigenous ethnicity. When affected, the palatal mucosa provides the best site to obtain a representative biopsy. Since ENKTCL-NT is highly aggressive, it is extremely important to recognize the spectrum of clinical presentations and microscopic features in order to avoid misdiagnosis and treatment delay.

The impact of early diagnosis on the prognosis of extranodal NK/T-cell lymphoma with massive lung involvement: a case report

Background

Pulmonary non-Hodgkin lymphoma (NHL) is rare. The most frequent subtype of pulmonary NHL is low-grade B-cell lymphoma, such as lymphoma of mucosa-associated lymphoma tissue. Extranodal natural killer cell/T-cell lymphoma, nasal type (ENKL) is characterized by predominant extranodal involvement and association with Epstein-Barr virus (EBV). ENKL with massive lung involvement has been infrequently reported, and its prognosis is extremely poor.

Case presentation

A 20-year-old Japanese man presented with intermittent fever lasting for 2 months. Radiological imaging demonstrated multiple nodules of uneven shape and size in both lungs. Video-assisted thoracic surgical lung biopsy showed abnormal lymphocyte infiltration, which was positive for CD3, CD56, and perforin. In situ hybridization for EBV-encoded RNA was positive. From these findings, he was diagnosed with ENKL with lung involvement. The patient was successfully treated with intensive combinational chemotherapy followed by allogeneic cord blood transplantation. He has been alive with continuous complete remission for 1 year after diagnosis.

Conclusions

Although ENKL involving the lung has been reported to have dismal outcomes, our patient showed long-term survival after intensive chemotherapy and up-front allogeneic hematopoietic transplantation. The present case highlights the importance of early diagnosis as well as allogeneic transplantation.

Extranodal NK/T-cell lymphoma in adolescents: imaging findings of a consecutive 7-year case series

Objectives

Extranodal NK/T-cell lymphoma is reportedly a rare but emerging type of lymphoma in adolescents. The present study was performed to specify its imaging characteristics.

Methods

Our hospital’s picture archiving and communication systems were searched from January 2009 to December 2016. We identified 13 patients aged <18 years with pathologically confirmed extranodal NK/T-cell lymphoma in the head and neck region. The computed tomography and magnetic resonance images were reviewed to summarize the imaging characteristics of extranodal NK/T-cell lymphoma in adolescents.

Results

The mean age at onset was 15.2 ± 1.46 years (range, 12–17 years) with a male:female ratio of 1.17:1.00. Most of the patients (n = 10) displayed nasal cavity and/or paranasal involvement. The tumor was homogeneous in both computed tomography and magnetic resonance images and showed slight enhancement. No calcification or liquefactive necrosis was observed. Adjacent structures were usually involved.

Conclusion

Suggestive imaging characteristics could acquaint specialists with extranodal NK/T-cell lymphoma in adolescents, facilitating improved early recognition of the diagnosis and helping to improve the patient’s outcome.

Epstein-Barr Virus-Associated T and NK-Cell Lymphoproliferative Diseases

EBV-associated T and NK-cell lymphoproliferative diseases (EBV-T/NK LPDs) are characterized by the transformation and proliferation of EBV-infected T or NK cells. The 2016 revised World Health Organization classification recognizes the following EBV-positive lymphoproliferative disorders (LPD): chronic active EBV infection (CAEBV) of T- and NK-cell type (cutaneous and systemic forms), systemic EBV-positive T-cell lymphoma of childhood, aggressive NK-cell leukemia, extranodal NK/T-cell lymphoma, nasal type, and the new provisional entity primary EBV-positive nodal T/NK-cell lymphoma. EBV-associated hemophagocytic lymphohistiocytosis (HLH), although not included in the WHO classification because it is a reactive, inflammatory disease, is included in this review because it can be life-threatening and may have overlapping features with other EBV+ T/NK LPDs. EBV+ T/NK LPDs are rare diseases difficult to diagnose and manage properly, because some LPDs have unusual presentations, and discrepancies between clinical and histological findings might be encountered. Furthermore, EBV+ T/NK disorders share some clinico-pathological features, and may evolve into other categories during the clinical course, including malignant transformation of CAEBV. Here, we review the EBV+ T/NK LPDs in terms of their definitions, clinical features, histology, immunophenotype, molecular findings, and pathogenesis. This review aims to increase our understanding and awareness of the differential diagnosis among the different EBV+ T/NK LPDs. New insights into the genetic characteristics of these disorders will also be discussed.

CD30-positive cutaneous extranodal natural killer/T-cell lymphoma: clinicopathological features and survival outcomes

BACKGROUND

The prognostic value of CD30 expression in cutaneous extranodal natural killer/T-cell lymphoma is controversial.

METHODS

Clinicopathological features, survival outcomes, and prognostic implications of CD30 were retrospectively analyzed in 55 patients with cutaneous extranodal natural killer/T-cell lymphoma. We classified patients into (i) primary cutaneous extranodal natural killer/T-cell lymphoma and (ii) cutaneous extranodal natural killer/T-cell lymphoma secondary to nasal disease depending on the primary tumor site.

RESULTS

CD30+ cutaneous extranodal natural killer/T-cell lymphoma was more common in patients with cutaneous extranodal natural killer/T-cell lymphoma secondary to nasal disease than in those with primary cutaneous disease. CD30+ cases were more likely to present nodular lesions or cellulitis-like swelling than CD30- cases. Histologically, CD30+ cutaneous extranodal natural killer/T-cell lymphoma predominantly comprised large tumor cells compared with CD30- cases. However, the clinical morphology and tumor cell size were not associated with survival outcomes. CD30 expression was associated with better survival outcomes in patients with cutaneous extranodal natural killer/T-cell lymphoma secondary to nasal disease.

CONCLUSION

CD30+ cutaneous extranodal natural killer/T-cell lymphoma presented peculiar clinicopathological features and had more favorable disease course in patients with cutaneous dissemination from nasal disease.

Beneath the Retinal Pigment Epithelium: Histopathologic Findings in Metastatic Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type

Purpose

To report a case of extranodal natural killer/T-cell lymphoma (ENKTCL), nasal type metastatic to the space beneath the retinal pigment epithelium (RPE) with coincident paraneoplastic lymphoma-associated retinopathy.

Methods

Findings of clinical and histopathologic examination are presented with differential diagnoses and a literature review.

Case Report

A 53-year-old man presented with bilateral blindness and had exudative retinal detachments overlying subretinal masses in both eyes. Flow cytometry of pericardial fluid revealed malignant T lymphocytes. After two cycles of chemotherapy, the patient was hospitalized and quickly expired. Autopsy revealed lymphoma involving the eyes, heart, right lung, and two subcarinal lymph nodes focally. Histopathologic examination of the eyes revealed intraocular metastases from ENKTCL, nasal type. Expression of CD3 and CD56, along with expression of Epstein-Barr virus by in situ hybridization, confirmed the diagnosis. Lymphomatous infiltrates were confined to the space beneath the neurosensory retina and between the RPE and the Bruch membrane, sparing the uveal tissue, similar to other metastatic T-cell lymphomas. Extensive RPE and photoreceptor loss in regions with and without underlying tumor was typical of a concurrent paraneoplastic lymphoma-associated retinopathy.

Conclusion

Patients diagnosed with ENKTCL should be evaluated by an ophthalmologist, as ophthalmic involvement portends a poor prognosis.

Natural killer/T-cell lymphoma with concomitant syndrome of inappropriate antidiuretic hormone secretion: A case report and review of literature

We report a case of natural killer (NK)/T-cell lymphoma with concomitant syndrome of inappropriate antidiuretic hormone secretion (SIADH). The patient was a 64-year-old woman with a history of nasopharyngeal carcinoma of over 30 years. She was admitted with a chief complaint of intermittent fever for 2 mo. Palpation after admission indicated a swollen lymph node below the left jaw. Multiple imaging examinations on admission indicated multiple enlarged lymph nodes throughout the body. We performed a left submandibular lymph node biopsy, and the results revealed NK/T-cell lymphoma. A biochemical examination indicated Epstein-Barr virus positivity. At the same time, the patient developed hyponatremia. Based on her laboratory examination and clinical manifestation, decreased plasma osmolality, urine osmolality greater than plasma osmolality, lack of skin swelling, normal blood pressure, normal renal function, no adrenal function detected on serology, and no abnormalities in imaging examination of the adrenal glands, the likelihood of SIADH in the patient was high. After fluid restriction and administration of sodium chloride, the patient’s blood sodium level gradually increased. Subsequently, the immune function of the patient declined, there were severe symptoms of infection, and she died of respiratory failure. NK/T-cell lymphoma associated with SIADH has not, to our knowledge, been previously reported in PubMed. This case emphasizes the importance of monitoring serum ion levels, especially serum sodium, in patients with NK/T-cell lymphoma.

Gambogic acid induces cell apoptosis through endoplasmic reticulum stress triggered inhibition of Akt signaling pathways in extranodal NK/T-cell lymphoma cells

As the chemotherapeutic resistance of extranodal NK/T-cell lymphoma (ENKTL) rises year by year, searching for novel chemoprevention compounds has become imminent. Gambogic acid (GA) has recently been shown to have anti-tumor effects, but its role and underling mechanism in ENKTL are rather elusive. In the present study, we showed that GA inhibited the cell growth and potently induced the apoptosis of ENKTL cells in vitro in a time- and concentration-dependent manner. Furthermore, GA induced cell death through endoplasmic reticulum stress (ERS) mediated suppression of Akt signaling pathways and finally the release of the caspase-3 proteases. Overall, our data provided evidences supporting GA as a potential therapeutic agent for ENKTL, which may facilitate further preclinical development of anti-tumor drugs.

Comparison of Diagnostic Cytomorphology of Natural Killer/T-Cell Lymphoma (Nasal Type) in Conventional Smears, Liquid-Based Preparations, and Histopathology

Natural killer (NK)/T-cell lymphoma is formally referred to as extranodal NK/T-cell lymphoma, nasal type (ENKTCL), in the 2008 and 2016 World Health Organization (WHO) classifications. NK/T-cell lymphoma, nasal type, is a rare but clinically important lymphoid neoplasm. It is the predominant type of extranodal lymphoma associated with the Epstein–Barr virus (EBV). NK/T-cell lymphoma is marked by a wide cytomorphological spectrum. The cytological findings may be so subtle that NK/T-cell lymphoma could possibly be easily overlooked. Here, we report a case of NK/T-cell lymphoma involving the sinonasal region with lymph node involvement. Fine needle aspiration of the neck lymph node and punch biopsy of the nasal mucosa were performed. The diagnosis of NK/T-cell lymphoma was confirmed based on pathological and immunohistochemical analyses, as well as in situ hybridization for EBV-encoded mRNA (EBER). The present case report underlines the importance of prompt clinicopathological assessment in suspected cases. The comparison of cytomorphologic features of NK/T-cell lymphoma in various specimens is presented.

Clinical characteristics of primary intestinal NK/T cell lymphoma, nasal type: Case series and review of the literature

BACKGROUND

Primary intestinal NK/T cell lymphoma is rare but aggressive and exhibits a poor prognosis. Little is known about its clinical characteristics because few studies with small sample sizes have been reported.

AIMS

To provide clinicopathological features and endoscopic findings and to summarize the treatment outcomes of primary intestinal NK/T cell lymphoma to improve our understanding of this disease.

METHODS

Between January 2011 to December 2016, 13 patients with confirmed primary gastrointestinal NK/T cell lymphoma at our center were described, and an updated literature review was provided.

RESULTS

In this series of 13 cases, 69.23% were men, the median age was 39 years, and the median survival was 6 months. The common clinical manifestations included abdominal pain (76.92%) and gastrointestinal bleeding (46.15%). Lymphomas were common in the large intestine (69.23%). In 76.92% of patients, the clinical staging was stage I, and all 13 patients manifested ulcerative lesions and no tumor mass on endoscopy. The clinical characteristics of primary intestinal NK/T cell lymphomas were similar to results in existing literature.

CONCLUSION

Intestinal NK/T cell lymphoma shows nonspecific clinical features and poor prognosis, which is mainly expressed as ulcers on endoscopy. Emergency surgery may be an adverse prognostic factor of lymphoma, since it is prone to progress toward gastrointestinal perforation.

Natural Killer/T-cell Neoplasms: Analysis of Incidence, Patient Characteristics, and Survival Outcomes in the United States

BACKGROUND

Limited data are available regarding the incidence, survival patterns, and long-term outcomes of natural killer (NK)/T-cell neoplasms in the United States.

PATIENTS AND METHODS

We performed a retrospective study of patients with NK/T-cell neoplasms diagnosed from 2001 to 2014 using the Surveillance, Epidemiology, and End Results program database. The Kaplan-Meier method was used to estimate the overall survival difference among the subgroups. Multivariate analyses were used to determine the factors affecting survival.

RESULTS

For the 797 patients with NK/T-cell lymphoma, nasal type, the median age at diagnosis was 53 years, and males tended to be younger at diagnosis (P < .0001). The incidence of the disease increased from 0.4 in 2001 to 0.8 in 2014 per 1,000,000 individuals. The incidence was significantly greater in Hispanic patients compared with that in non-Hispanic patients (rate ratio, 3.03; P = .0001). The median overall survival was 20 months (range, 2-73 months) and varied significantly according to the primary site (P < .0001) and the disease stage at diagnosis (P < .0001). NK/T-cell lymphoma patients had an increased risk of acute myeloid leukemia (standardized incidence ratio, 18.77; 95% confidence interval, 2.27-67.81). For the 105 NK/T-cell leukemia patients, the median age at diagnosis was 58 years (range, 4-95 years). The overall incidence of the disease was 0.09 per 1,000,000 individuals and was significantly greater in males (rate ratio, 0.41; P < .0001). Unlike NK/T-cell lymphoma, no racial disparities were found in the incidence. The median overall survival was 17 months (range, 0-36 months).

CONCLUSION

The incidence of NK/T-cell lymphoma, nasal type, in the United States has at least doubled in the past decade, with the greatest predilection among Hispanics. Patients with NK/T-cell lymphoma might have an increased risk of the subsequent development of acute myeloid leukemia.

Novel Immunotherapy Options for Extranodal NK/T-Cell Lymphoma

Extranodal NK/T-cell lymphoma (ENKTCL) is a highly aggressive mature NK/T-cell neoplasm marked by NK-cell phenotypic expression of CD3ε and CD56. While the disease is reported worldwide, there is a significant geographic variation with its highest incidence in East Asian countries possibly related to the frequent early childhood exposure of Epstein-Barr virus (EBV) and specific ethnic-genetical background, which contributes to the tumorigenesis. Historically, anthracycline-based chemotherapy such as CHOP (cyclophosphamide, adriamycin, vincristine, and prednisone) was used, but resulted in poor outcomes. This is due in part to intrinsic ENKTCL resistance to anthracycline caused by high expression levels of P-glycoprotein. The recent application of combined modality therapy with concurrent or sequential radiation therapy for early stage disease, along with non-anthracycline-based chemotherapy regimens consisting of drugs independent of P-glycoprotein have significantly improved clinical outcomes. Particularly, this neoplasm shows high sensitivity to l-asparaginase as NK-cells lack asparagine synthase activity. Even still, outcomes of patients with advanced stage disease or those with relapsed/recurrent disease are dismal with overall survival of generally a few months. Thus, novel therapies are needed for this population. Clinical activity of targeted antibodies along with antibody-drug conjugates, such as daratumumab (naked anti-CD38 antibody) and brentuximab vedotin (anti-CD30 antibody conjugated with auristatin E), have been reported. Further promising data have been shown with checkpoint inhibitors as high levels of programmed death-ligand 1 expression are observed in ENKTCL due to EBV-driven overexpression of the latent membrane proteins [latent membrane protein 1 (LMP1) and LMP2] with activation of the NF-κB/MAPK pathways. Initial case series with programmed death 1 inhibitors showed an overall response rate of 100% in seven relapsed patients including five with a complete response (CR). Furthermore, cellular immunotherapy with engineered cytotoxic T lymphocytes targeted against LMP1 and LMP2 have shown encouraging results with durable CRs as either maintenance therapy after initial induction chemotherapy or in the relapsed/refractory setting. In this paper, we review this exciting field of novel immunotherapy options against ENKTCL that hopefully will change the treatment paradigm in this deadly disease.

Aggressive natural killer (NK)-cell leukaemia and extranodal NK/T-cell lymphoma are two distinct diseases that differ in their clinical presentation and cytogenetic findings

AIMS

Aggressive natural killer (NK)-cell leukaemia (ANKCL) and extranodal NK/T-cell lymphoma (ENKTCL) with secondary bone marrow involvement are rare bone marrow NK/T-cell neoplasms and share similar features. This study aimed to distinguish these two entities.

METHODS AND RESULTS

We studied bone marrow NK/T-cell neoplasms by classifying them into those with no extramedullary mass (group 1, eight cases) and those with extramedullary mass (group 2, 13 cases). The two groups showed similar clinical presentations and pathological features. Fever and cytopenia were the most common clinical presentations in both groups. The neoplastic cells varied from small and relatively monotonous cells to large pleomorphic cells. In six cases (two in group 1, and four in group 2), the neoplastic infiltrate was inconspicuous, consisting of ≤10% of marrow cells in the interstitium, which were hardly identified by haematoxylin and eosin staining alone. Nearly all patients rapidly died, regardless of the neoplastic infiltrate volume. All of the group 1 patients fulfilled the World Health Organisation 2017 diagnostic criteria of ANKCL, and their survival was significantly worse than that of the group 2 patients (P = 0.035). In addition, there was a significant association between being in group 1 and chromosome 7 abnormalities. Chromosome 6q deletion, which is commonly reported in ENKTCL, was seen in two of our group 2 patients, and was not observed in any of our group 1 patients.

CONCLUSION

ANKCL with no extramedullary mass should be distinguished from ENKTCL with bone marrow involvement, as the former shows distinct outcomes and genetic features.

Evaluation of the proliferation marker Ki-67 in a large prostatectomy cohort

The tumor proliferation index marker Ki-67 is strongly associated with tumor cell proliferation, growth and progression, and is widely used in routine clinicopathological investigation. Prostate cancer is a complex multifaceted and biologically heterogeneous disease, and overtreatment of localized, low volume indolent tumors, is evident. Here, we aimed to assess Ki-67 expression and related outcomes of 535 patients treated with radical prostatectomy. The percentage of tumor epithelial cells expressing Ki-67 was determined by immunohistochemical assay, both digital image analysis and visual scoring by light microscope were used for quantification. The association of Ki-67 and prostate cancer was evaluated, as well as its prognostic value. There was a positive correlation between high expression of Ki-67 and Gleason score > 7 (p < 0.001) as well as tumor size (≥ 20 mm, p = 0.03). In univariate analyses, a high expression of Ki-67 in tumor epithelium was significantly associated with biochemical failure (BF) (digital scoring, p = 0.014) and (visual scoring, p = 0.004). In the multivariate analyses, a high level of Ki-67 was an independent poor prognostic factor for biochemical failure-free survival (BFFS) (Visual scoring, Ki67, p = 0.012, HR:1.50, CI95% 1.10–2.06). In conclusion, high Ki-67 expression is an independent negative prognostic marker for biochemical failure. Our findings support the role of Ki-67 as a significant, poor prognostic factor for in prostate cancer outcome.

Extranodal NK/T Cell Lymphoma, Nasal Type (ENKTL-NT): An Update on Epidemiology, Clinical Presentation, and Natural History in North American and European Cases

PURPOSE OF REVIEW

Extranodal NK/T cell lymphoma, nasal type (ENKTL-NT) is an aggressive extranodal non-Hodgkin lymphoma most commonly occurring in East Asia and Latin America but with increasing incidence in the United States. Data on epidemiology, disease presentation, and outcome for European and North American ("Western") cases are very limited. We review published landmark clinical studies on ENKTL-NT in the West and report in detail recent data, including our institutional experience.

RECENT FINDINGS

We highlight key observations in its epidemiology, natural history, and trends in clinical management. In the USA, ENKTL-NT is more common among Asian Pacific Islanders (API) and Hispanics compared to non-Hispanic whites. Published studies indicate less heterogeneity in clinical presentation in Western ENKTL-NT compared to Asian patients. While there is variation in age at diagnosis, presence of antecedent lymphoproliferative disorders, and outcomes among racial/ethnic groups, the universal association of ENKTL-NT with EBV and the poor response of this neoplasm to anthracycline-based therapy is consistent across all geographic areas. Data on epidemiology, disease presentation, and clinical outcomes in mature T cell and NK cell (T/NK cell) neoplasms, including ENKTL-NT, in Europe and North America are very limited. As the classification and diagnostic characterization of the currently recognized T/NK cell lymphoma disease entities continue to evolve, gaps and inconsistencies in data reporting across different studies are being recognized. Despite these limitations, several studies from the USA suggest that the incidence of ENKTL-NT is higher in Asian Pacific Islanders (API) and non-white Hispanics and that outcomes may be worse in non-whites. However, the universal association of ENKTL-NT with Epstein-Barr virus (EBV) across all ethnic groups suggests a common pathogenesis. Given the overlap between the entities included in the category of T/NK cell neoplasms, there is a need to further define biological and clinical differences that may affect diagnosis, treatment, and outcome.

Extranodal nasal-type natural killer/T-cell lymphoma with penile involvement: a case report and review of the literature

Background

Extranodal natural killer/T-cell lymphoma (ENKTL) usually presents as a localized disease in the nasal cavity; extension to the male genitourinary system is very rare and has been characterized only recently. Most cases present with predominantly extranodal involvement, advanced stage disease, highly aggressive course, and strong association with Epstein-Barr virus (EBV). While metastasis is common in ENKTLs, the penis is rarely involved in both nasal and non-nasal ENKTLs and only one report was published to date.

Case presentation

One patient with NK/T-cell lymphoma, presented initially with a penile mass, is reported. The 58-year-old man who presented with progressive painless penile swelling underwent penectomy for penile tumor. Histologically, the glans and foreskin revealed neoplastic infiltration of medium-sized lymphoma cells expressing CD56, CD3, granzyme-B, and labeled for EBV-encoded RNA in situ hybridization. Findings were consistent with NK/T-cell lymphoma. By detailed history, we learned that the patient had nasal obstruction for more than 10 years. Nasopharyngeal involvement was screened with PET-CT; ENKTL was diagnosed after a nasopharyngeal biopsy. The final diagnosis was primary nasal NK/T-cell lymphoma, with metastasis to the penis. Additional sites of disease appeared soon afterward (adrenal gland, liver, spleen and lymph nodes). The patient died within 4 months.

Conclusion

This study suggested that penile NK/T-cell lymphoma tends to disseminate early and pursues an aggressive course. It is imperative to distinguish nasal NK/T lymphoma from other types of tumors, because the prognosis and treatment differ significantly for secondary metastases.

Primary cutaneous NK/T-cell lymphoma of nasal type: an age-related lymphoproliferative disease?

Among extranodal NK/T-cell lymphoma of nasal type (NKTL), the extranasal variant (ENKTL) is known to have a worse prognosis with advanced clinical stage than the nasal variant of NKTL. However, detailed clinicopathological features of the localized extranasal disease have not been well documented in English literature. Here, we described the clinicopathological profiles of 14 patients with stage I ENKTL, including 7 in the skin, 5 in the gastrointestinal tract, and 2 in the central nervous system, highlighting the distinctiveness of the first. The 7 primary cutaneous (PCNKTL) cases were characterized by an older onset age (median, 76 versus 53 years, P=.012) and a more favorable clinical course (P=.041) compared with 17 patients with stages II-IV ENKTL that showed cutaneous involvement. The skin lesions in the PCNKTL group were distributed in the face or neck (n=4) and limbs (n=3) but not the trunk, which was most frequently affected (60%, P=.017) in the latter group. Furthermore, the stage I cutaneous disease showed a female predominance (male-female, 2:5 versus 7:0; P=.021) and a significantly more favorable survival compared with the noncutaneous stage I ENKTL (P=.037). These results suggest that PCNKTL constitute a distinct subgroup in the nasal-type lymphoma spectrum.

Epstein-Barr Virus-associated Lymphoproliferative Disorders in the Skin

Epstein-Barr virus (EBV)-associated lymphoproliferations involving the skin are a rare but important group of diseases with a broad spectrum of behavior, ranging from self-limiting spontaneously resolving disorders to highly aggressive malignancies. They may be of B, T, or natural killer (NK) cell type and include EBV-positive mucocutaneous ulcer, lymphomatoid granulomatosis, EBV-positive diffuse large B-cell lymphoma, hydroa vacciniforme-like lymphoproliferative disorder, and extranodal NK/T-cell lymphoma of nasal type. Recognition and distinction of these entities is important in view of their differing prognoses and treatments. An association with EBV may be the first indication that a patient is immunosuppressed.

Virus-associated neoplasms of the nasopharynx and sinonasal tract: diagnostic problems

A significant fraction of nasopharyngeal and sinonasal tumors are associated with Epstein-Barr virus (EBV) or human papillomavirus (HPV). Nasopharyngeal carcinoma (NPC) and extranodal NK/T-cell lymphoma harbor EBV in practically all cases, although a small proportion of cases of the former harbor HPV. Sinonasal inverted papillomas harbor HPV in about 25% of cases. Sinonasal squamous cell carcinomas harbor transcriptionally active HPV in about 20% of cases, and limited data suggest that this subset has a better prognosis than the HPV-negative subset. This review addresses the diagnostic issues of the EBV-associated tumors. Difficulties in diagnosis of NPC may be encountered when there are prominent crush artifacts, many admixed lymphoid cells masking the neoplastic cells, or numerous interspersed granulomas, whereas benign cellular components (epithelial crypts and germinal centers) and reactive lymphoid hyperplasia can potentially be mistaken for NPC. Immunostaining for pan-cytokeratin and/or in situ hybridization for EBER can help in confirming or refuting a diagnosis of NPC. The main diagnostic problem of extranodal NK/T-cell lymphoma is recognition of the neoplastic nature of those examples predominated by small cells or showing a mixture of cells. The identification of a destructive infiltrate (dense expansile infiltrate; angiocentric growth) and definite cytologic atypia (clear cells; many medium-sized cells) would favor a diagnosis of lymphoma, which can be supported by immunohistochemistry (most commonly CD3+, CD5-, CD56+) and in situ hybridization for EBER. In conclusion, among nasopharyngeal and sinonasal neoplasms, demonstration of EBV may aid in diagnosis, particularly NPC and extranodal NK/T-cell lymphoma. Demonstration of HPV does not have a role yet in diagnosis, although this may change in the future.

Small round blue cell tumors of the sinonasal tract: a differential diagnosis approach

One of the most challenging diagnostic categories within tumors of the sinonasal tract is the small round blue cell tumors. Biopsies are usually small and limited, resulting in considerable diagnostic difficulty for practicing surgical pathologists. These tumors share several overlapping histologic and immunophenotypic findings while also showing considerable variation within and between cases. Specific tumor site of origin, imaging findings, and clinical findings must be combined with the histology and pertinent ancillary studies if the correct diagnosis is to be reached. Discrimination between neoplasms is critical as there are significant differences in therapy and overall outcome. It is important to have a well developed differential diagnosis for this category of tumors, where each of the diagnoses is considered, evaluated, and either confirmed or excluded from further consideration. In an undifferentiated tumor, showing a small round blue cell morphology, using the mnemonic 'MR SLEEP' helps to highlight tumors to consider: melanoma, mesenchymal chondrosarcoma, rhabdomyosarcoma, sinonasal undifferentiated carcinoma, squamous cell carcinoma (including NUT carcinoma), small cell osteosarcoma, lymphoma, esthesioneuroblastoma (olfactory neuroblastoma), Ewing sarcoma/primitive neuroectodermal tumor, pituitary adenoma, and plasmacytoma. A panel of pertinent immunohistochemistry studies, histochemistries and/or molecular tests should aid in reaching a diagnosis, especially when taking the pattern and intensity of reactions into consideration.

Treatment outcomes of and prognostic factors for definitive radiotherapy with and without chemotherapy for Stage I/II nasal extranodal NK/T-cell lymphoma

Treatment strategies for nasal extranodal NK/T-cell lymphoma (ENKTL), including sequential chemotherapy followed by radiotherapy (SCRT), concurrent chemoradiotherapy (CCRT), or radiotherapy alone (RT), remain varied. The purpose of this study was to assess the treatment outcome, the toxicity, and the potential prognostic factors for patients with early-stage nasal ENKTL treated using definitive RT (minimum of 50 Gy) with or without chemotherapy. From 1998 to 2014, 37 patients were included in the study. Eight patients were treated with RT alone, 1 with CCRT, and 28 with SCRT. Local regional control (LRC), progression-free survival (PFS), and overall survival (OS) were calculated using the Kaplan-Meier method. RT resulted in an overall response rate of 91.2%, with a complete response rate of 78.4%. After a median follow-up time of 36.8 months, the 3-year LRC, PFS and OS were 87.4%, 64.0% and 76.3%, respectively. Acute severe toxicity (Grade 3) of mucositis was observed in 6 (16.2%) of the 37 patients. In univariate analyses, extensive disease (Stage I/II with local invasiveness) and the presence of B symptoms were significantly associated with a poor PFS, whereas extensive disease was significantly associated with a poor OS. Multivariate analysis identified the presence of extensive disease as an independent predictor of PFS (P < 0.001) and OS (P = 0.015). High-dose RT with or without chemotherapy reported promising locoregional control and a favorable outcome for patients with early-stage nasal ENKTL without local invasiveness. Further investigation of new treatment strategies for patients with local invasiveness is warranted.

Cutaneous EBV-related lymphoproliferative disorders

This article will focus on the cutaneous lymphoproliferative disorders associated with EBV, with an emphasis on the upcoming changes in the revised 4th Edition of the WHO classification of tumors of the hematopoietic system, many of which deal with cutaneous disorders derived from NK-cells or T-cells. Extranodal NK/T-cell lymphoma usually presents in the upper aerodigestive tract, but can involve the skin secondarily. EBV-associated T- and NK-cell lymphoproliferative disorders (LPD) in the pediatric age group include the systemic diseases, chronic active EBV infection (CAEBV) and systemic EBV+ T-cell lymphoma of childhood. Hydroa vacciniforme (HV)-like LPD is a primarily cutaneous form of CAEBV and encompasses the lesions previously referred to as HV and HV-like lymphoma (HVLL). All the T/NK-cell-EBV-associated diseases occur with higher frequency in Asians, and indigenous populations from Central and South America and Mexico. Among the B-cell EBV-associated LPD two major changes have been introduced in the WHO. The previously designated EBV-positive diffuse large B-cell lymphoma (EBV-DLBCL) of the elderly, has been changed to EBV-DLBCL with 'not otherwise specified' as a modifier (NOS). A new addition to the WHO system is the more recently identified EBV+ mucocutaneous ulcer, which involves skin and mucosal-associated sites.

Extended Course and Increased Dose of Initial Chemotherapy for Extranodal Nasal Type Natural Killer/T (NK/T)-Cell Lymphoma in Patients <60 Years Old: A Single-Center Retrospective Cohort Study

BACKGROUND Extranodal NK/T-cell lymphoma (ENKTL) of the nasal type is highly invasive and relatively resistant to chemotherapy. This study aimed to assess the efficacy and safety of an extended chemotherapy regimen with increased dose intensity. MATERIAL AND METHODS This was a retrospective cohort study of 69 patients <60 years old with an ECOG score 0-2 treated for ENKTL at the Second Affiliated Hospital of Xi'an Jiaotong University between January 2004 and December 2013. The outcomes were compared between patients who received >8 courses of high-intensity chemotherapy (n=37) vs. 6-8 courses (n=18) and <6 courses (n=14) of conventional chemotherapy. Regimens included improved CHOP, CHOP-E, EPOCH, MAED, MMED, SMILE, and Hyper-CVAD with an increased dose intensity in the >8 courses group. RESULTS The mean follow-up was 52 months (8 to 82 months). Remission rate did not differ significantly when compared among the 3 groups after 3 courses of chemotherapy (83.8%, 77.8%, and 78.6%, respectively, overall P=0.834), but the 5-year overall survival (OS) differed significantly (63.5%, 45.1%, and 22.9%, respectively, overall P=0.030), as did progression-free survival (PFS) (59.1%, 36.0%, and 15.1%, respectively, overall P=0.020), disease-free survival (DFS) (54.1%, 35.5%, and 12.9%, respectively, overall P=0.022), and total relapse rate throughout follow-up (37.04%, 50.0%, and 88.89%, respectively, overall P=0.027). There were no differences in adverse effects among the 3 groups. CONCLUSIONS These results suggest improved OS, PFS, DFS, and relapse rate in young patients with ENKTL receiving >8 courses of high-intensity chemotherapy.

Predictors of survival of natural killer/T-cell lymphoma, nasal type, in a non-Asian population: a single cancer centre experience

Background

Natural killer/T-cell lymphoma (NKTCL), part of T-cell and NK-cell neoplasms in the World Health Organisation (WHO) classification, is an aggressive lymphoma with poor prognosis more predominantly seen in Asian and South American countries. This study evaluates the factors associated with survival among patients with newly diagnosed NKTCL in Peru.

Methods

Information was abstracted from medical records (MR) for all NKTCL patients >13 years of age at the Instituto Nacional de Enfermedades Neoplasicas (INEN) between 2002 and 2011. The estimate of the survival curves was performed by the Kaplan-Meier method, and the difference was computed by the log-rank test.

Results

Around 226 MR were reviewed, 153 met the selection criteria, the median age was 40 years (14–84). The median progression-free survival (PFS) was 20 months, five year PFS was 42.6%, univariable analysis (UA) showed statistical significance (p < 0.05) for male sex, non-nasal primary site, advanced clinical stages, B symptoms, poor performance status, regional nodal involvement (RNI). In the multivariate analysis the only poor prognostic factors was primary non-nasal (Hazard ratio (HR) = 2.40, 95% confidence interval (CI) = 1.43– 4.02, P = 0.01). The median overall survival (OS) was 49 months, five year OS was 48.9%, UA showed statistical significance for non-nasal primary site, advanced clinical stages, B symptoms, lactate dehydrogenase (LDH) > normal, RNI and local tumour invasion. In the multivariate analysis, primary non-nasal was the only poor prognostic factor with HR = 2.57, 95% CI = 1.37–4.83, P = 0.03.

Conclusions

In Peru, OS of NKTCL is similar to other countries. This result suggests that non-nasal NKTCL is the only poor prognostic factor of OS and PFS.

A phase 2 study of methotrexate, etoposide, dexamethasone, and pegaspargase chemotherapy for newly diagnosed, relapsed, or refractory extranodal natural killer/T-cell lymphoma, nasal type: a multicenter trial in Northwest China

The nasal type of extranodal natural killer/T‐cell lymphoma is a rare aggressive lymphoma with poor prognosis. To discover a successful treatment, we investigated the efficacy and safety of chemotherapy with methotrexate, etoposide, dexamethasone, and polyethylene glycol‐asparaginase (MESA). Three cycles of MESA were administered to 46 patients with new or relapsed/refractory natural killer/T‐cell lymphoma. Complete response after 3 treatment cycles was 43.5%, the overall response rate was 87%, and 2‐year overall survival was 83.4%. Complete response was significantly better for newly diagnosed patients than for patients with relapsed/refractory disease. Patients with newly diagnosed disease had a significantly better overall response rate after 1, but not after 2 or 3 treatment cycles. Overall survival and progression‐free survival did not differ over 2 years. Grade 1/2 toxicities were frequent, but MESA was associated with fewer grade 3/4 events or treatment‐related deaths. These results will require confirmation in larger prospective trials.

Delayed diagnosis of sinonasal lymphoma due to bilateral manifestation

The objective of this study is to analyze the presenting symptoms, the time to correct diagnosis and outcome of a European patient cohort with sinonasal lymphoma focusing on unilateral vs. bilateral sinonasal involvement. In a retrospective setting in a European tertiary referral center, eleven patients (9 males, 2 females) with sinonasal lymphoma diagnosed between 2002 and 2015 were identified and divided into a unilateral and bilateral group according to their CT finding. Clinical findings on first presentation, the presence of B symptoms, the radiologic findings, overall survival and disease-specific survival were assessed. 55 % of the patients suffered from bilateral manifestation, which was associated with a delayed diagnosis (10 vs. 1.5 months, p < 0.05). B symptoms (67 vs. 0 %) and death of disease (50 vs. 0 %) were observed only in the bilateral group. Nasal NK/T-cell lymphoma was the most frequent diagnosis, followed by diffuse large B-cell lymphoma. Bilateral mucosal manifestation with B symptoms was shown to be common within the rare entity of sinonasal lymphomas and patients with bilateral sinonasal manifestation are at risk for a delayed diagnosis with worse outcome.

Primary Intestinal Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type: A Comprehensive Clinicopathological Analysis of 55 Cases

Purpose

To investigate the clinicopathological features, survival and prognostic factors of primary intestinal extranodal natural killer/T-cell lymphoma, nasal type (PI-ENKTCL).

Methods

Clinical and histological characteristics of PI-ENKTCL cases were retrospectively evaluated. Immunohistochemical phenotype and status of Epstein-Barr virus (EBV) and T-cell receptor (TCR) gene rearrangement were examined. The overall survival and prognostic parameters were also analyzed.

Results

Fifty-five (2.7%) cases with PI-ENKTCL were identified out of 2017 archived ENKTCL cases, with a median age of 39 years and a male to female ratio of 2.1:1. The most common symptom was abdominal pain (90.9%), accompanied frequently with fever and less commonly with intestinal perforation or B symptoms. Small intestine (50.9%) was the most common site to be involved. 47.3% and 36.4% cases presented with stage I and II diseases, respectively. Histologically, most cases displayed characteristic morphologic changes of ENKTCL. Cytoplasmic CD3, TIA-1 and CD56 expression was found in 100%, 94.5% and 89.1% of cases, respectively. In situ hybridization detection for EBV demonstrated positive results in all cases. Monoclonal TCR gene rearrangement was found in 52.9% of tested cases. Chemotherapy with a DICE or L-asparaginase/peg-asparginase-containing regimen was most often employed. Both advanced tumor stage and B symptoms were independent inferior prognostic factors (p = 0.001 and p = 0.010). Noticeably, 6 cases demonstrated a CD4-positive phenotype. These cases featured a relatively older median age (58 years), predominance of small/medium-sized neoplastic cells, a higher rate of TCR rearrangement and slightly favorable outcome.

Conclusion

We reported by far the largest series of PI-ENKTCL, and demonstrated its heterogeneity, aggressive clinical behavior and unsatisfying response to the current therapeutic strategies. Those CD4-positive cases might represent a unique subtype of PI-ENKTCL or distinct entity. Further investigations are required for the better understanding and management of this unusual disease.

Encouraging experience in the treatment of nasal type extra-nodal NK/T-cell lymphoma in a non-Asian population

Extra-nodal NK/T-cell lymphoma, nasal type (EN-NK/TCL-NT), is rare in the Western world. We launched the current single-institutional retrospective study with Institutional Review Board approval to better understand the disease. 43 EN-NK/TCL-NT patients treated from 1996 to 2014 were analyzed, including 10 (23%) Asians and 33 (76%) non-Asians. 19/26 (73%) early-stage patients received short-course chemotherapy followed by radiotherapy. 14/17 (82%) advanced-stage patients received primary chemotherapy. Complete response rate was significantly higher in the modified-SMILE group than the accelerated-CHOP group (80% vs. 30%, p = 0.015). The 2-year overall survival (OS) and progression-free survival (PFS) were 60% and 40%, respectively. Early-stage disease had significantly higher 2-year OS (87% vs. 21%) and PFS (56% vs.18%) than advanced-stage (p < 0.001). Ethnicity had no prognostic difference. EN-NK/TCL-NT in non-Asians shared similar disease characteristics and treatment outcomes with Asians. Most early-stage patients have achieved durable remissions. Management of advanced-stage disease remains challenging, with frequent progression and high mortality.

Nasal-type NK/T-cell lymphomas are more frequently T rather than NK lineage based on T-cell receptor gene, RNA, and protein studies: lineage does not predict clinical behavior

Extranodal natural killer (NK)/T-cell lymphoma (ENKTL), nasal type, comprises NK or cytotoxic T cells. We evaluated the clinical impact of cell type and the usefulness of T-cell receptor (TCR) gene transcripts in distinguishing cell lineage. One hundred and eight cases of ENKTL were analyzed for TCR gene rearrangements using the BIOMED-2 protocol and for TCR gene expression using immunohistochemistry for TCR-βF1 and TCR-cγM1, and RNA in situ hybridization for TCR gene transcripts. Prognostic factors were analyzed. Among the 108 cases, 44 were monoclonal for a TCR rearrangement (40%) while 64 (60%) were undefinable. The monoclonal cases expressed TCR-βF1 in 14 out of 40 cases (35%) and TCR-cγM1 in 1 out of 44 cases (2%). The 64 undetermined cases expressed TCR-βF1 in 15 cases (23%) and TCR-cγM1 in 1 (2%). Thirteen of 40 TCR-β constant gene transcript-positive cases (33%) expressed TCR-βF1 and one of nine TCR-γ constant gene transcript-positive cases (11%) expressed TCR-cγM1. TCR gene transcripts were not useful in the distinction of cell lineages. TCR gene transcripts were positive in ENKTLs as well as in normal B cells and aggressive NK-cell leukemia. Based on gene rearrangements and immunohistochemistry for TCR, there were 60 T-cell type cases (56%), 32 NK-cell type cases (30%), and 16 cases with an undetermined cell type (14%). TCR protein was expressed in 30/60 T-ENKTLs (50%) in a variable fraction of tumor cells. There were no significant differences in clinical findings or overall patient survival between T- or NK-cell types of ENKTL, although those with a T-cell type tended to show a better prognosis for those with localized nasal lymphomas. Univariate and multivariate analysis showed that a non-nasal ENKTL, age >60 years, high level of lactate dehydrogenase, bone marrow involvement, and the absence of radiotherapy were independent prognostic factors.

Diabetes, Epstein-Barr virus and extranodal natural killer/T-cell lymphoma in India: Unravelling the plausible nexus

The International Diabetes Federation Diabetes Atlas estimates a staggering 590 million people affected with diabetes mellitus (DM) within the next two decades globally, of which Type 2 DM will constitute more than 90%. The associated insulin resistance, hyperinsulinemia, and hyperglycemia pose a further significant risk for developing diverse malignant neoplasms. Diabetes and malignancy are multifactorial heterogeneous diseases. The immune dysfunction secondary to Type 2 diabetes also reactivates latent infections with high morbidity and mortality rates. Epstein-Barr virus (EBV), a ubiquitous human herpes virus-4, is an oncogenic virus; its recrudescence in the immunocompromised condition activates the expression of EBV latency genes, thus immortalizing the infected cell and giving rise to lymphomas and carcinomas. Extranodal natural killer/T-cell lymphoma (ENKTCL), common in South-East Asia and Latin America; is a belligerent type of non-Hodgkin lymphoma (NHL) almost invariably associated with EBV. An analysis of articles sourced from the PubMed database and Google Scholar web resource until February 2014, suggests an increasing incidence of NHL in Asia/India and of ENKTCL in India, over the last few decades. This article reviews the epidemiological evidence linking various neoplasms with Type 2 DM and prognosticates the emergence of ENKTCL as a common lymphoreticular malignancy secondary to Type 2 diabetes, in the Indian population in the next few decades.

Disseminated Mycobacterium marinum Infection With a Destructive Nasal Lesion Mimicking Extranodal NK/T Cell Lymphoma: A Case Report

Mycobacterium marinum is a ubiquitous waterborne organism that mainly causes skin infection in immunocompetent patients, and its disseminated infection is rare. Extranodal NK/T cell lymphoma, nasal type (ENKL) usually localizes at the nasal and/or paranasal area, but occasionally disseminates into the skin/soft tissue and gastrointestinal tract. Compromised immunity is a risk factor for developing nontuberculous mycobacterial (NTM) infection and malignant lymphoma, and the 2 diseases may share similar clinical presentation; however, only a few reports have described NTM infection mimicking malignant lymphoma.A 43-year-old Japanese man presented to our hospital complaining of multiple progressive skin nodules and purulent nasal discharge for 3 weeks. He was diagnosed with Crohn disease with refractory enteropathic arthritis and has been treated with anti-tumor necrosis factor alpha agents for 25 years. Fiberoptic nasal examination revealed septal perforation with hemorrhagic mucus and purulent rhinorrhea. Histological examination of the nasal septum revealed the infiltration of atypical medium-to-large-sized cells with erosion. The cells were positive for cytoplasmic CD3, granzyme B, and Epstein-Barr virus-encoded small RNA. Histological examination of the skin nodules and auricle also showed infiltration of atypical lymphocytes. The patient was tentatively diagnosed with ENKL, and chemotherapy was considered. However, the skin lesions decreased in size after discontinuation of immunosuppressive agents and minocycline administration. Two weeks later, nasal septum and lavage fluid and left leg skin cultures were positive for M marinum, and minocycline was discontinued. The skin and the nasal lesions improved after 2 months. To the best of our knowledge, this is the first case of disseminated M marinum infection with a destructive nasal lesion mimicking ENKL. The differentiation between M marinum infection and ENKL is clinically important because misdirected treatment leads to a poor prognosis. NTM infections including M marinum should be considered in differential diagnosis of ENKL. Bacterial cultures, pathological analysis, and close monitoring are required for the differentiation of ENKL and disseminated M marinum infection; both are serious diseases and early diagnostic distinction between them and immediate appropriate treatment will improve the patient's prognosis.

Extranodal Natural Killer/T-Cell Lymphoma of the Nasal Type with Skin Metastases

Extranodal natural killer/T-cell lymphoma (ENKL) of the nasal type is a rare, clinically aggressive disease. ENKL of the nasal type is often localized in the upper aerodigestive tract, including the nasal cavity, nasopharynx, paranasal sinuses, tonsils, hypopharynx and larynx, and usually presents as stage I/II. Extranasal involvement can occur, and a common site of extranasal involvement or metastatic disease includes the skin. Identifying skin metastases is important for the appropriate staging and treatment. We report a case of ENKL of the nasal type that presented with localized disease and subsequent skin lesions that were consistent with skin metastases.

Nasal Cavity and Paranasal Sinuses

The nasal cavity and paranasal sinuses occupy the top of the upper respiratory tract and form pneumatic spaces connected with the atmosphere. They are located immediately beneath the base of the cranium, where crucial vital structures are harbored. From this region, very much exposed to airborne agents, arise some of the more complex and rare benign and malignant lesions seen in humans, whose difficulties in interpretation make this remarkable territory one of the most challenging in the practice of surgical pathology.

Contents of this chapter cover inflammations and infections, polyps and pseudotumors, fungal and midfacial destructive granulomatous lesions, as well as benign, borderline, and malignant neoplasms. Among the neoplasms, emphasis is made on those entities characteristic or even unique for the sinonasal region, such as Schneiderian papillomas, glomangiopericytoma, intestinal- and non-intestinal-type adenocarcinomas, olfactory neuroblastoma, nasal-type NK-/T-cell lymphoma, and teratocarcinosarcoma. Moreover, recently recognized entities involving this territory, i.e., HPV-related non-keratinizing carcinoma, NUT carcinoma, and SMARCB1-deficient basaloid carcinoma, are also discussed in the light of their specific molecular findings. Furthermore, the text is accompanied by numerous classical and recent references, several tables, and 100 illustrations.

Extranodal NK/T-Cell Lymphoma, Nasal Type, Presenting as a Breast Mass

Extranodal natural killer/T-cell lymphoma, nasal type, is a rare type of non-Hodgkin cell lymphoma endemic to East Asia and parts of Central and South America. In most cases, it is driven by Epstein-Barr virus infections, with a broad range of morphologic appearances, frequent necrosis, and angioinvasion. It is designated as NK/T reflecting uncertainty in its cellular origins. These tumors usually arise in the nasal region, typically presenting with symptoms of nasal obstruction, epistaxis, and/or a destructive mass involving the nose, sinuses, or palate. The treatment of patients with extranodal NK/T-cell lymphoma, nasal type, is largely determined by the extent of disease. Localized disease is usually treated with radiation and chemotherapy. The disseminated disease requires combination chemotherapy. This report describes the case of a 30-year-old Caucasian female presenting with a left breast mass of two months duration. Excisional biopsy was done, and the pathological exam confirmed the diagnosis of extranodal NK/T-cell lymphoma, nasal type. Our patient received a systemic combination chemotherapy with steroid (dexamethasone), methotrexate, ifosfamide, L-asparaginase, and etoposide (SMILE) regimen, resulting in a complete clinical and radiological remission. On the basis of our review of the literature, extranodal NK/T non-Hodgkin cell lymphoma, nasal type, presenting as a breast mass is very rare and very uncommon in the United States. Awareness of this occurrence may be valuable as this case may be a forerunner of additional similar cases developing in the future.