Epstein–Barr virus-related plasmablastic lymphomas arising from long-standing sacrococcygeal cysts in immunosuppressed patients:

Oral Plasmablastic Lymphoma: A Rare Manifestation of HIV-Related Neoplasm-A Brief Clinical Study

Plasmablastic lymphoma (PBL) is an uncommon and aggressive large B-cell lymphoma commonly diagnosed in human immunodeficiency virus-positive patients. Though the oral cavity is a common site for PBL, this condition is not commonly reported in the literature as an oral manifestation. Most oral PBLs presented as an asymptomatic swelling, frequently associated with ulcerations and bleeding. No standard treatment is yet advocated for oral PBL. Five-year survival rate was recorded not more than 33.5%. This presentation emphasizes on oral manifestation of plasmablastic lymphoma (PBL) as a rare entity, which was provisionally diagnosed for carcinoma (CA) oral cavity. A simple presentation of ulcerated growth in the upper jaw was excised for histopathologic evaluation. Subsequently, it turned out to be a rare oral manifestation of HIV-related lymphoma. It is imperative to understand simple oral presentation as a manifestation of an underlying systemic condition. With this interest, this case presentation is published with a literature review.

Mediastinal syndrome from plasmablastic lymphoma in human immunodeficiency virus and human herpes virus 8 negative patient with polycythemia vera: a case report

Background

Plasmoblastic lymphoma is a rare and aggressive subtype of diffuse large B cell lymphoma, which occurs usually in the jaw of immunocompromised subjects.

Case presentation

We describe the occurrence of plasmoblastic lymphoma in the mediastinum and chest wall skin of an human immunodeficiency virus-negative 63-year-old Caucasian man who had had polycytemia vera 7 years before. At admission, the patient showed a superior vena cava syndrome, with persistent dyspnoea, cough, and distension of the jugular veins. Imaging findings showed a 9.7 × 8 × 5.7 cm mediastinal mass. A chest wall neoformation biopsy and ultrasound-guided fine-needle aspiration biopsy of the mediastinal mass allowed diagnosis of plasmoblastic lymphoma and establishment of an immediate chemotherapeutic regimen, with rapid remission of compression symptoms.

Conclusions

Plasmoblastic lymphoma is a very uncommon, difficult to diagnose, and aggressive disease. The presented case represents the first rare mediastinal plasmoblastic lymphoma in a human immunodeficiency virus-/human herpesvirus-8-negative patient. Pathologists should be aware that this tumor does appear in sites other than the oral cavity. Fine-needle aspiration biopsy is a low-cost, repeatable, easy-to-perform technique, with a high diagnostic accuracy and with very low complication and mortality rates. Fine-needle aspiration biopsy could represent the right alternative to surgery in those patients affected by plasmoblastic lymphoma, being rapid and minimally invasive. It allowed establishment of prompt medical treatment with subsequent considerable reduction of the neoplastic tissue and resolution of the mediastinal syndrome.

Human immunodeficiency virus-negative plasmablastic lymphoma: A case report and literature review

RATIONALE

Plasmablastic lymphoma (PBL) is a rare subtype of human immunodeficiency virus (HIV)-related non-Hodgkin's lymphoma that predominantly manifests in the oral cavity.

PATIENT CONCERNS

Three cases of HIV-negative PBL were reported.

DIAGNOSES

HIV-negative PBL INTERVENTIONS:: The patient had undergone chemotherapy.

OUTCOMES

Clinical outcomes were very poor in Cases 1 and 3; Case 2, whose diagnosis suggested no bone marrow involvement, is still alive.

LESSONS SUBSECTIONS

These cases served to broaden the reported clinical spectrum of HIV-negative PBL. Clinicians and pathologists need to be familiar with lymphoma in the identified extra-oral PBL variation and there levant differential diagnosis procedures for this particular disease.

Dramatic treatment response of cutaneous plasmablastic lymphoma in an HIV patient: a case report

Plasmablastic lymphoma is a variant of diffuse large B-cell lymphoma, characterized by rapid progression and is associated with a poor outcome. We report a 35-year-old male with poorly controlled HIV infection and AIDS who presented with skin lesions and swelling throughout the body. Computed tomography (CT) revealed innumerable enhancing soft tissue masses within the subcutaneous soft tissues and lymphadenopathy. Plasmablastic lymphoma was diagnosed, patient was treated with chemotherapy, and post treatment CT demonstrated complete resolution. Imaging plays a key role in the diagnosis and surveillance of this disease.

Clinicopathologic features of plasmablastic lymphoma: Single-center series of 8 cases from Saudi Arabia

BACKGROUND

Plasmablastic lymphoma (PBL) is a rare subtype of non-Hodgkin's lymphoma. Characterized by its aggressive nature and plasmacytic differentiation, PBL remains a therapeutic and diagnostic challenge; it generally has a poor prognosis with very few long-term survivors and most patients dying within 2 years from initial presentation. PBL has been reported in several other countries; however, there have been no reported cases from Saudi Arabia. Here, we report 8 cases of PBL depicting the clinical presentation, immunocompetency, immunphenotypic characterization, diagnostic challenges and treatment outcome.

METHODS

The medical records were reviewed for clinical presentation, staging, laboratory data, radiological studies, treatments, and outcomes. A broad immunohistochemical panel consisting of CD45, CD3, CD20, CD79a, Pax5, CD38, CD138, MUM1, EMA, Kappa, Lambda, CD 56, CD30, Bcl-2, Bcl-6, Alk-1, Ki-67, EBV-LMP-1, and HHV8 was performed.

RESULTS

The tumors predominantly exhibited immunoblastic/plasmablastic or plasmacytic morphologic features and had a plasma cell-like immunophenotype. All cases were immunoreactive for CD38, CD138 and MUM1 confirming plasma cell differentiation of the tumor cells. CD20 was negative for all cases; whereas CD79a and Pax5 were weakly positive in 2cases. All 8 cases were EBV-LMP-1/EBER-1 negative, and 1 case was HHV8 positive. Similar to previously published studies, PBL in Saudi Arabia is characterized by male predominance (6/8), median age 51.5 years (mean age 46 years), associated with early dissemination, poor response to therapy, and limited survival (average survival time, 6.4 months, median overall survival 5.5 months). However, it does have some unique features. It occurs more commonly in immunocompetent persons (6/8, 75%), is not associated with EBV infection (0/8), and nodal involvement (either primary or secondary) is common among patients (6/8). In addition, extra-oral sites are more common than oral/nasal cavities (7/8) and the c-myc gene is not common (1/8, 12.5%).

CONCLUSION

It appears that PBL is heterogeneous in terms of clinical presentation and morphology. PBL is a therapeutic challenge with a clinical course that is characterized by its high rate of relapse and death. To date, treatment responses are usually partial and temporary. Therapies that are more intensive than CHOP do not seem to prolong survival. Further research is needed to understand the biology and molecular pathogenesis of PBL in order to improve therapies.

VIRTUAL SLIDES

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1465801416161912.

Human immunodeficiency virus-negative plasmablastic lymphoma: a comprehensive analysis of 114 cases

Human immunodeficiency virus-negative plasmablastic lymphoma (PBL) is an extremely rare entity. Its clinicopathological features, optimal treatment strategy and prognostic factors remain obsure. An extensive search was performed in the English language literature within the Pubmed database using the key words: ‘plasmablastic lymphoma and human immunodeficiency virus-negative or immunocompetent’. Data from 114 patients from 52 articles were analyzed. The mean patient age at diagnosis was 58.90 years (range, 2–86). HIV-negative PBL showed a predilection for elderly individuals (patients older than 60 years, 56.14%) and affected more males than females (M:F, 2.29:1). Ann Arbor stage IV patients accounted for 39.22% while bone marrow involvement was less frequent (12.79%). The Ki-67 index was high with a mean expression of 83%. Epstein-Barr virus (EBV) infection was common being positive in 58.70% of the patients while herpesvirus-8 (HHV-8) infection was rare being positive in only 7.55% of the patients. Immunosuppression was noted in 28.16% of patients. The median overall survival (OS) was 19 months. The 1- and 2-year survival rates were 52.3 and 45.3%, respectively. Age, gender and primary site showed no strong relationship with OS while Immunosuppression, Ann Arbor stage IV and EBV negativity were able to predict a poorer OS. Either complete remission (CR) or partial remission (PR) was superior to the refractory group in OS (P<0.0001 and P=0.0066, respectively). For stage I patients, the application of radiotherapy did not improve the OS. In conclusion, HIV-negative PBL is a distinct entity likely occurring in elderly and immunosuppressed individuals. Immunosuppression status, Ann Arbor stage IV, EBV negativity and refractory to treatment are poor prognostic factors of OS in HIV-negative PBL.

Extraoral plasmablastic lymphoma detected using ascitic fluid cytology and flow cytometry: a case report with a review of the literature

BACKGROUND

Plasmablastic lymphoma (PL) is a relatively new category of lymphoma, which has been considered to be found predominantly in the oral cavity and has a strong association with HIV.

CASE

We report a case of extraoral/mesenteric PL detected using cytological examination of ascitic fluid assisted by flow cytometric (FC) analysis. The cells were positive for CD38, CD138, CD10, CD45 and CD56 and negative for CD3, CD19, CD20 and CD79a, with cytoplasmic lambda light-chain restriction. We also reviewed 67 cases of extraoral PL from the available literature and found them to be less often associated with HIV (than oral PL), occurring mostly in males aged 30-60 years, with the most common extraoral site being the anorectal region.

CONCLUSION

A high index of suspicion at the level of the cytopathologist is imperative for identifying lymphoma cells in a body fluid. A rare entity like PL can also be diagnosed on cytology assisted by ancillary techniques (like FC), without the need for a biopsy. We also suggest that the minimum panel to diagnose PLs should include CD138, MUM-1, Ki-67, ALK-1, CD3, immunoglobulin light-chains, CD20 and PAX5.

A case report of cecal plasmablastic lymphoma in a HIV-negative patient

Plasmablastic lymphoma (PBL) is a unique type of diffuse proliferation of large neoplastic lymphoid cells most of which resemble B immunoblasts, but all tumor cells show the immunophenotype of plasma cells. It has a strong predilection for jaw and oral cavity in HIV-positive patients. Incidences of extraoral location of this tumor is increasingly being recognized especially in HIV-negative patients for example, stomach, jejunum, omentum, anorectum, lungs, testes, soft tissues, lymph nodes, bone marrow, skin, and central nervous system. We present a case of PBL found in cecum in an HIV-negative patient. It was accompanied by lung and lymph node involvement and presented as abdominal mass. This is only the second reported case of PBL originating in cecum.

Human immunodeficiency virus (HIV)-negative plasmablastic lymphoma: a single institutional experience and literature review

Plasmablastic lymphoma (PBL) is a rare aggressive B-cell lymphoproliferative disorder. HIV-negative PBL has not been extensively reported. Nine HIV-negative PBL patients evaluated at Moffitt Cancer Center were studied. Eight patients had extranodal diseases. All patients were treated with CHOP or hyper-CVAD. Responses were observed in 8 cases (7 complete, 1 partial responses). Four patients underwent consolidation with autologous hematopoietic stem cell transplant (HSCT) in first complete remission (CR1). At median follow-up of 23.9 months, 7 patients were alive and 5 were disease-free. Aggressive induction chemotherapy and consolidation with autologous HSCT in CR1 might be considered for patients with HIV-negative PBL.

HIV-negative plasmablastic lymphoma: not in the mouth

Plasmablastic lymphoma (PBL) is an aggressive variant of non-Hodgkin lymphoma initially reported in the oral cavity of HIV-positive individuals. Since its original description, several cases have been reported in patients who do not have HIV infection. However, despite its recognition as a distinct subtype of diffuse large B-cell lymphoma several years ago, comprehensive reviews of this entity are lacking. A MEDLINE search through June 2010 was performed to identify cases with a pathologic diagnosis of HIV-negative PBL based on morphology and minimal immunohistochemical criteria. Our study included a total of 76 cases. The median age was 57 years (range, 1 to 90 years) with a male-to-female ratio of 1.7. Seventy-four percent of cases did not have an apparent association with immunosuppression, 18% had a concurrent lymphoproliferative or autoimmune disorder and 9% developed PBL after solid organ transplantation. Oral involvement was observed in 21%, advanced stage in 60%, Epstein-Barr virus-encoded RNA expression was positive in 45% and Ki-67 expression of greater than or equal to 80% in 61% of the cases. Chemotherapy was documented in 43 patients, from which 43% received the cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP)-like regimens. The median and the 2-year overall survival for the whole group were 9 months and 10%, respectively. Patients who had HIV-negative PBL have distinct clinicopathological characteristics, such as short overall survival and lower rates of oral involvement and Epstein-Barr virus-encoded RNA expression than the previously reported in HIV-positive patients.

Extraoral plasmablastic lymphoma with intravascular component and MYC translocation

Plasmablastic lymphoma (PBL) is an uncommon, clinically aggressive, Epstein-Barr virus-driven B-cell lymphoma that was initially described in tumors of relatively young human immunodeficiency virus-positive men. Subsequent to initial reports, the clinical and pathological spectrum of this disease has been expanded such that, now, PBL is recognized to be a heterogeneous disease entity. Plasmablastic lymphoma has been seen in clinical settings outside those initially reported and has been shown to demonstrate a variety of morphologic patterns. We describe a case of extraoral PBL in an human immunodeficiency virus-infected patient with a computed tomography-identified heterogeneously enhancing mass in the stomach. Histologically, a prominent intravascular component was identified. Fluorescent in situ hybridization analysis for MYC/IGH (immunoglobulin heavy chain) rearrangement t(8;14) identified fusion signals, confirming the presence of MYC rearrangement. The presence of a prominent intravascular in our case is unique. To our knowledge, these findings have not been observed in the previous reports of PBL. The observation of this vascular component supports the heterogeneity of PBL and may be an indicator of tumor aggressiveness. We were able to demonstrate the MYC/IGH rearrangement in our case of PBL. The interplay between Epstein-Barr virus and this MYC rearrangement may be similar to what is observed in Burkitt lymphoma, another clinically aggressive non-Hodgkin lymphoma.

Prognostic factors in chemotherapy-treated patients with HIV-associated Plasmablastic lymphoma

BACKGROUND

Plasmablastic lymphoma (PBL) is a variant of diffuse large B-cell lymphoma commonly seen in the oral cavity of HIV-infected individuals. PBL has a poor prognosis, but prognostic factors in patients who have received chemotherapy have not been adequately evaluated.

METHODS

An extensive literature search rendered 248 cases of PBL, from which 157 were HIV(+). Seventy cases with HIV-associated PBL that received chemotherapy were identified. Whenever possible, authors of the original reports were contacted to complete clinicopathological data. Univariate analyses were performed calculating Kaplan-Meier estimates and compared using the log-rank test.

RESULTS

The mean age was 39 years, with a male predominance. The mean CD4(+) count was 165 cells/mm(3). Advanced clinical stage was seen in 51% and extraoral involvement was seen in 43% of the cases. The expression levels of CD20 and Epstein-Barr virus-encoded RNA were 13% and 86%, respectively. The overall survival duration was 14 months. In a univariate analysis, early clinical stage and a complete response to chemotherapy were associated with longer survival. There was no apparent difference in survival with regimens more intensive than cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP).

CONCLUSIONS

Patients with HIV-associated PBL have a poor prognosis. Prognosis is strongly associated with achieving a complete clinical response to CHOP or CHOP-like chemotherapy. The role of more intensive regimens is currently unclear. Further research is needed to improve responses using novel therapeutic agents and strategies.

Plasmablastic lymphoma: a review

Plasmablastic lymphoma (PBL) has been recently characterised as an aggressive subtype of non-Hodgkin's lymphoma, most frequently arising in the oral cavity of HIV-infected patients. To date, approximately 60 cases fulfilling the clinico-pathological characteristics of PBL have been reported. PBLs are composed of large cells with eccentrically located nuclei and deeply basophilic cytoplasm with a paranuclear hof. The tumour cells are invariably immunoreactive for the plasma cell marker CD138, and show monoclonal rearrangement of the immunoglobulin heavy chain gene (IgH) and/or clonal restriction of the Ig light chain (IgL) gene expression in most of the cases. Similar to other types of AIDS-related lymphomas, there is evidence that Epstein-Barr virus and Kaposi-sarcoma associated Human Herpes Virus 8 may play a relevant role in the pathogenesis of PBL. PBL patients have been treated heterogeneously, with a combination of chemotherapy, radiotherapy and/or surgery, and their prognosis is usually poor, with a death rate of approximately 60% at 1 year.

Plasmablastic lymphoma of the oral cavity: a rapidly progressive lymphoma associated with HIV infection

Plasmablastic lymphoma of the oral cavity is a form of non-Hodgkin lymphoma (NHL) and was first described in 1997. We describe a case of plasmablastic lymphoma in an HIV-infected patient who presented with an expanding oral lesion and symptoms of a toothache. We review all cases of plasmablastic lymphoma that have been reported in the literature. Plasmablastic lymphoma is strongly associated with immunodeficiency, and most particularly, with HIV infection. The pathophysiological origin of plasmablastic lymphoma has not been fully characterised, but the presence of Epstein-Barr virus (EBV) has often been documented in biopsy specimens, supporting a role for EBV in the pathogenesis of this lymphoma. The differential diagnosis for an expanding oral lesion includes both infectious and malignant processes. Biopsy is essential for making a correct and prompt diagnosis. Treatment usually involves chemotherapy, but antiretroviral therapy may also have an important role. Infectious disease clinicians should be aware of this newly described and increasingly encountered lymphoma, since it is prominently associated with immunosuppression and may be mistaken for other entities.

KSHV/HHV8-associated primary cutaneous plasmablastic lymphoma in a patient with Castleman's disease and Kaposi's sarcoma

We report a unique case of Kaposi's sarcoma (KS)-associated herpesvirus (KSHV)/human herpesvirus (HHV)8-associated lymphoma in a 56-year-old man with a history of acquired immune deficiency syndrome, Castleman's disease, KS, and idiopathic thrombocytopenic purpura. Three months following the diagnosis of KS affecting a left cervical lymph node and Castleman's disease with bone marrow involvement, he presented with a subcutaneous, tender lesion on his left arm. A skin biopsy demonstrated a superficial and deep, interstitial-nodular infiltrate of severely atypical lymphoid cells showing plasmacytoid features, numerous mitotic figures, and frequent individual apoptotic tumor cells. The morphologic features were those of plasmablastic lymphoma (PBL). Immunohistochemical study showed that the lymphoma cells strongly expressed CD45, CD30, and KSHV/HHV8 latency-associated nuclear antigen. KSHV/HHV8 was also detected in the biopsy sections of the patient's KS and Castleman's disease. Epstein-Barr virus in situ hybridization was diffusely positive. In situ hybridization demonstrated kappa-light chain restriction. Although KSHV/HHV8 has been individually associated with KS, Castleman's disease, and PBL, this appears to be the first reported case in which all three entities were present simultaneously in one person, suggesting a critical role of KSHV/HHV8 as a common denominator in the pathogenesis of these diseases.

Epstein-Barr virus-associated B-cell lymphoma in the setting of iatrogenic immune dysregulation presenting initially in the skin

BACKGROUND

Epstein-Barr virus (EBV) has been implicated in B-cell lymphoma associated with iatrogenic immune dysregulation, primarily in the context of extracutaneous lymphoma.

METHODS

We describe six patients, five transplant recipients receiving cyclosporine and one patient with rheumatoid arthritis receiving methotrexate, who developed cutaneous presentations of EBV-associated B-cell lymphoma. Human herpesvirus 8 (HHV8) and EBV thymidine kinase (vTK) expression were also explored.

RESULTS

The cases comprised plasmablastic lymphoma (one case), plasmacytic marginal zone lymphoma (two cases), and diffuse large B-cell lymphoma (three cases). There was a monoclonal gammopathy in one and concurrent extracutaneous disease in two of the six patients. EBV-associated latent small nuclear RNA was detected in all cases with coexpression of HHV8 in one of the five cases and of vTK in three of the six cases. Three patients responded to a reduction in the immunosuppressive regimen and antiviral therapy. Recurrent disease developed in two, with one patient succumbing to multiorgan dissemination.

CONCLUSIONS

EBV-associated cutaneous B-cell lymphoma is characterized by a long interval between the initiation of immunosuppression and the development of lymphoma. Although previous reports have reported an indolent clinical course, an aggressive clinical course may occur. HHV8 and lytic phase EBV antigens are detected in some cases, possibly suggesting a pathogenetic role.

Oral plasmablastic lymphoma in an HIV-negative patient: A case report and review of the literature

Plasmablastic lymphoma is an HIV-associated non-Hodgkin's lymphoma that primarily affects the oral cavity and jaws. The purpose of this report is to describe the first case of plasmablastic lymphoma occurring in an HIV-negative, nonimmunocompromised individual, and to review the histopathologic and immunohistochemical phenotype of this lymphoma. Histopathologically, our case exhibited a dense, diffuse lymphocytic infiltrate of noncohesive large lymphocytes with plasmacytoid features. Immunohistochemical analysis revealed positivity for the B-cell marker CD79a, VS38c, Epstein-Barr virus latent membrane protein (LMP), immunoglobulin G (IgG), and lambda light chain restriction. Neoplastic cells were negative for leukocyte common antigen, CD20, CD3, CD10, CD138, Bcl-2, Bcl-6, desmin, actin, EMA, S-100, HMB45, Alk-1, HHV8, IgA, IgM, and cytokeratin. The features of this rare disease are summarized based on a comprehensive review of the epidemiologic, clinical and immunohistochemical findings of previously reported cases.

Epstein-Barr virus- and human herpesvirus 8-associated primary cutaneous plasmablastic lymphoma in the setting of renal transplantation

BACKGROUND

Plasmablastic lymphoma (PBL) is a recently recognized entity most often reported in the oral cavity, mainly in the setting of underlying human immunodeficiency viral infection whereby a role for Epstein-Barr virus (EBV) and more recently human herpesvirus 8 (HHV8) has been described. Although EBV has been implicated in a variety of lymphoproliferative lesions, until recently HHV8 has only been associated with primary effusion lymphoma, multicentric Castleman's disease, and Kaposi's sarcoma. We describe a case of PBL occurring in the setting of renal transplantation.

METHODS

We encountered a case of PBL occurring in the setting of renal transplantation. We characterized the tumor by routine immunohistochemistry and evaluated for the presence of immunoglobulin light chain restriction and EBV RNA by in situ hybridization. We assessed for the presence of HHV8 RNA by reverse transcriptase in situ hybridization.

RESULTS

The tumor showed a histomorphology compatible with a PBL. In addition, there was strong RNA expression in the neoplastic cells for EBER-1, EBER-2, and HHV8.

CONCLUSION

This case suggests a possible role of both viruses in the pathogenesis of PBL in sites other than the oral cavity and expands the spectrum of post-transplantation lymphoproliferative disease to include PBL.

Diffuse Large B-cell Lymphomas With Plasmablastic Differentiation Represent a Heterogeneous Group of Disease Entities

Plasmablastic lymphoma was initially described as a variant of diffuse large B-cell lymphoma (DLBCL) involving the oral cavity of HIV+ patients and characterized by immunoblastic morphology and a plasma cell phenotype. However, other lymphomas may exhibit similar morphologic and immunophenotypic features. To determine the significance of plasmablastic differentiation in DLBCL and examine the heterogeneity of lymphomas with these characteristics, we examined 50 DLBCLs with low/absent CD20/CD79a and an immunophenotype indicative of terminal B-cell differentiation (MUM1/CD38/CD138/EMA-positive). We were able to define several distinct subgroups. Twenty-three tumors were classified as plasmablastic lymphoma of the oral mucosa type and showed a monomorphic population of immunoblasts with no or minimal plasmacytic differentiation. Most patients were HIV+ and EBV was positive in 74%. Eleven (48%) cases presented in the oral mucosa, but the remaining presented in other extranodal (39%) or nodal (13%) sites. Sixteen cases were classified as plasmablastic lymphoma with plasmacytic differentiation. These were composed predominantly of immunoblasts and plasmablasts, but in addition exhibited more differentiation to mature plasma cells. Only 33% were HIV+, EBV was detected in 62%, and 44% had nodal presentation. Nine cases, morphologically indistinguishable from the previous group, were secondary extramedullary plasmablastic tumors occurring in patients with prior or synchronous plasma cell neoplasms, classified as multiple myeloma in 7 of the 9. Two additional neoplasms were an HHV-8+ extracavitary variant of primary effusion lymphoma and an ALK+ DLBCL. HHV-8 was examined in 39 additional cases, and was negative in all. In conclusion, DLBCLs with plasmablastic differentiation are a heterogeneous group of neoplasms with different clinicopathological characteristics that may correspond to different entities.