Clinical, Morphologic, and Molecular Features of MAP3K8 Rearranged Spitz Neoplasms: A Retrospective Study Documenting That Bonafide Spitz Melanomas Are Rare.

Previous studies regarding the clinical behavior of Spitz neoplasms lack genomic characterization. We aim to assess our hypothesis that most MAP3K8 Spitz neoplasms are indolent despite MAP3K8 being the single most common driver of Spitz melanoma. Further, we aim to identify genomic features associated with aggressive behavior and to better characterize the morphology of these cases. We analyzed the outcomes of MAP3K8 Spitz neoplasms. We also performed a meta-analysis of the outcomes of MAP3K8 Spitz from the literature. Morphologic features were compared with other variants of Spitz using a Student t test and χ 2 test. Two of 35 cases resulted in local recurrence and one of these cases had local regional metastasis; all other cases had no evidence of recurrence (mean follow-up time: 33 mo). MAP3K8 Spitz only rarely results in aggressive behavior. Metastatic cases have genomic mutations associated with tumor progression. Morphologically, MAP3K8 Spitz neoplasms frequently showed nodular silhouette, large cell size, epithelioid morphology, and severe nuclear atypia resulting in more frequent diagnosis as Spitz melanoma. Most MAP3K8 Spitz neoplasms have excellent prognoses, apart from rare cases harboring additional genomic abnormalities associated with tumor progression.

Clinical, Morphologic, and Molecular Features of Benign and Intermediate-grade Melanocytic Tumors With Activating Mutations in MAP2K1.

Activating mutations in MAP2K1 can be seen in benign and intermediate-grade melanocytic neoplasms with spitzoid morphology. We analyzed the clinical, histopathologic, and genetic features for 16 cases of benign and intermediate-grade melanocytic tumors harboring activating MAP2K1 mutations. We compared them to Spitz neoplasms with characteristic Spitz fusions or HRAS mutation. We also compared the mutational pattern of benign and intermediate-grade MAP2K1 -mutated neoplasms and melanomas with activating MAP2K1 mutations. Among the 16 cases, the favored morphologic diagnosis was Spitz nevus (8/16), atypical Spitz tumors (6/16), and deep penetrating nevus (2/16). The 2 most common architectural patterns seen included a plaque-like silhouette with fibroplasia around the rete reminiscent of a dysplastic nevus (n=7) or a wedge-shaped or nodular pattern with the plexiform arrangement of the nests aggregating around the adnexa or neurovascular bundle (n=8). The cases with dysplastic architecture and spitzoid cytology resembled dysplastic Spitz nevi. Compared with true Spitz neoplasms, MAP2K1 -mutated neoplasms occurred in older age groups and had more frequent pagetosis and a lower average mitotic count. The most common type of mutation in the benign and intermediate-grade cases in the literature involves an in-frame deletion, while, in melanomas, missense mutations are predominant. Benign and intermediate-grade melanocytic neoplasms with activating mutations in MAP2K1 can have morphologic overlap with Spitz neoplasms. A significant proportion of melanomas also have activating MAP2K1 mutations. In-frame deletions are predominantly seen in the benign and intermediate-grade cases, and missense mutations are predominantly seen in melanomas.

NONO::TFE3 fusion cutaneous epithelioid and spindle cell tumor: A case series.

The NONO::TFE3 fusion has been described in MiT family translocation renal cell carcinomas as well as extracutaneous perivascular epithelioid cell tumors (PEComas). PEComas are known to express myogenic and melanocytic markers but SOX10 and p63 positivity has never been reported. We report two primary cutaneous tumors that morphologically and molecularly fit PEComas, both harboring the NONO::TFE3 fusion, but with an unusual immunophenotype of SOX10 and p63 positivity. One case was on an 80-year-old male's finger, and the other one was on a 72-year-old female's thigh. Both were well-circumscribed multinodular dermal tumors composed of nests of monotonous epithelioid to spindled cells with pale to vacuolated cytoplasm, some of which were arranged around blood vessels. Both tumors were positive for SOX10, S100, and p63, focally positive for Melan-A, and negative for myogenic markers. There are very little data regarding the molecular findings of primary cutaneous PEComas. While the NONO::TFE3 fusion has been identified in extracutaneous PEComas, it has never been reported in primary cutaneous cases. We believe these cases represent a previously undescribed subtype of cutaneous tumor which shows some immunophenotypic expression of melanocytic markers and we named these cases NONO::TFE3 fusion cutaneous epithelioid and spindle cell tumor. Further, we raise the question of whether this tumor should fall under the rubric of PEComa because of its morphology, partial expression of melanocytic markers, and the presence of the NONO::TFE3 fusion, or whether these tumors represent a separate novel class of tumors since the immunophenotypic expression of SOX10 and p63 is unusual for PEComas.

A reappraisal of the epidemiology of Spitz neoplasms in the molecular era: A retrospective cohort study.

BACKGROUND: Previous studies suggest that Spitz neoplasms occur primarily in younger patients, leading pathologists to shy away from diagnosing a benign Spitz neoplasm in the elderly. With the advent of genomic sequencing, there is a need for reappraisal of the epidemiology of Spitz neoplasms in the modern molecular era. OBJECTIVE: We aim to reassess the epidemiology of Spitz neoplasms incorporating next-generation sequencing. METHODS: We looked at 53,814 non-Spitz neoplasms and 1260 Spitz neoplasms including 286 Spitz neoplasms with next-generation sequencing testing and collected various epidemiologic data. RESULTS: In our general pool of cases, the proportion of Spitz neoplasm cases occurring is relatively the same in each of the first 4 decades of life with a precipitous drop in the fifth decade. In assessing a group of genomically verified cases of Spitz neoplasms, the drop was much less significant and up to 20% of all Spitz neoplasm cases occurred in patients over 50 years of age. LIMITATIONS: Limitations included the number of genetically verified Spitz neoplasm cases available and a possible bias as to which cases undergo genomic testing. CONCLUSION: Genomic verification may allow more confident diagnosis of Spitz neoplasms in patients over 50 years of age and avoid melanoma overdiagnosis.

Agminated presentation of fusion-driven melanocytic neoplasms.

BACKGROUND: The conventionally understood pathogenesis of agminated Spitz nevi includes a mosaic HRAS mutation followed by copy number gains in 11p. However, we have recently observed agminated presentations of fusion-driven melanocytic neoplasms. METHODS: We retrieved cases from our database of benign fusion-induced melanocytic neoplasms with an agminated presentation. Both the primary lesion and the secondary lesion were sequenced. TERT-promoter mutational testing and the melanoma fluorescence in situ hybridization assay were also performed. RESULTS: Three cases were included. Two had a PRKCA fusion (partners ATP2B4 and MPZL1) and one had a ZCCHC8::ROS1 fusion. None of the cases met morphologic or molecular criteria for malignancy. There was no evidence of tumor progression in secondary lesions. The same fusion was identified in the primary and secondary lesions. None of the patients developed evidence of nodal or systemic metastasis. CONCLUSIONS: We present accumulating evidence that fusion-driven melanocytic neoplasms can present with an agminated presentation. The differential diagnosis of an agminated presentation versus a locally recurrent or potentially locally metastatic tumor is critical, and accurate diagnosis has significant prognostic and therapeutic consequences for the patient. As with HRAS mutations, fusion-driven melanocytic tumors may have an agminated presentation.

PRAME Immunohistochemical Expression and TERT Promoter Mutational Analysis as Ancillary Diagnostic Tools for Differentiating Proliferative Nodules From Melanoma Arising in Congenital Nevi.

ABSTRACT: Proliferative nodules (PNs) are benign melanocytic proliferations that typically develop within congenital melanocytic nevi. These tumors have overlapping histological features with melanoma. Ancillary immunohistochemistry and genomic sequencing are often used in diagnostically challenging cases. To assess the utility of preferentially expressed antigen in melanoma (PRAME) immunoreactivity and telomerase reverse transcriptase (TERT) promoter mutation analysis in distinguishing PNs from melanoma arising in congenital nevi cases. Twenty-one PNs and 2 melanomas arising in congenital nevi were immunohistochemically stained with PRAME. Cases with adequate tissue were also assessed for TERT promoter mutations through sequencing studies. The positivity rates in the PN cases were compared with those of the melanomas. Two of 21 PN cases were diffusely positive for PRAME (≥75% of the tumor cells positive). Two of 2 melanomas arising in congenital nevus cases were also diffusely PRAME positive. The difference was statistically significant using a Fisher exact test. None of the tumors harbored TERT promoter mutations. PRAME immunohistochemical marker may have diagnostic value in distinguishing diagnostically challenging PNs from melanoma, but diffuse expression is not specific for melanoma.

Routine imaging guided by a 31-gene expression profile assay results in earlier detection of melanoma with decreased metastatic tumor burden compared to patients without surveillance imaging studies.

Patients with early-stage disease typically have a good prognosis, but still have a risk of recurrence, even with negative sentinel lymph node biopsy (SLNB). This study explores the utility of routine imaging to detect metastases in patients with negative SLNB but high-risk 31 gene expression profile (31-GEP) scores. We retrospectively identified melanoma patients with negative SLNBs. Patients with high-risk GEP results were placed in the experimental group and patients without GEP testing were placed in the control group. Among both cohorts, recurrent melanoma groups were identified. The tumor burden at the time of recurrence and the time to recurrence were compared between experimental group patients with routine imaging and control group patients without imaging schedules. We identified 327 control patients and 307 experimental patients, of which 14.1% versus 20.5% had melanoma recurrence, respectively. Of the patients with recurrent melanoma, those in the experimental group were older (65.75 versus 59.20), had higher Breslow depths (3.72 mm versus 3.31 mm), and had advanced tumor staging (89.5% versus 71.4% of patients presenting clinical stage ≥ II) compared to the control group at primary diagnosis. However, melanoma recurrence was detected earlier (25.50 months versus 35.35 months) in the experimental group at a lower overall tumor burden (73.10 mm versus 27.60 mm). A higher percentage of experimental patients started immunotherapy when offered (76.3% and 67.9%). Patients who received routine imaging after high-risk GEP test scores had an earlier recurrence diagnosis with lower tumor burden, leading to better clinical outcomes.

An update on genomic aberrations in Spitz naevi and tumours.

Spitz neoplasms continue to be a diagnostic challenge for dermatopathologists and are defined by distinctive morphological and genetic features. With the recent advancements in genomic sequencing, the classification, diagnosis, and prognostication of these tumours have greatly improved. Several subtypes of Spitz neoplasms have been identified based on their specific genomic aberrations, which often correlate with distinctive morphologies and biological behaviour. These genetic driver events can be classified into four major groups, including: (1) mutations [HRAS mutations (with or without 11p amplification) and 6q23 deletions]; (2) tyrosine kinase fusions (ROS1, ALK, NTRK1-3, MET and RET); (3) serine/threonine kinase fusions and mutations (BRAF, MAP3K8, and MAP2K1); and (4) other rare genomic aberrations. These driver genomic events are hypothesised to enable the initial proliferation of melanocytes and are often accompanied by additional genomic aberrations that affect biological behaviour. The discovery of theses genomic fusions has allowed for a more objective definition of a Spitz neoplasm. Further studies have shown that the majority of morphologically Spitzoid appearing melanocytic neoplasms with aggressive behaviour are in fact BRAF or NRAS mutated tumours mimicking Spitz. Truly malignant fusion driven Spitz neoplasms may occur but are relatively uncommon, and biomarkers such as homozygous 9p21 (CDKN2A) deletions or TERT-p mutations can have some prognostic value in such cases. In this review, we discuss the importance and various methods of identifying Spitz associated genomic fusions to help provide more definitive classification. We also discuss characteristic features of the various fusion subtypes as well as prognostic biomarkers.

Fractional excretion of phosphorus and vascular calcification in stage 3 chronic kidney disease.

The role of renal excretion of Pi in relation to vascular calcification (VC) in patients in the early stages of chronic kidney disease (CKD) is controversial. Thus, we determine the relation between fractional excretion of phosphorus (FEP) and VC, measured using two methods in a cross-sectional study of patients with stage 3 CKD. We recorded demographic data, anthropometry, comorbidities and active treatment. We measured 24-hour urine FEP and, in serum, measured fibroblast growth factor 23 (FGF23), α-Klotho, intact parathyroid hormone (iPTH), calcium and phosphorus. VC was measured by lateral abdominal radiography (Kauppila index (KI)) and CT of the abdominal aorta (measured in Agatston units). In 57% of subjects, abnormal VC was present when measured using CT, and in only 17% using lateral abdominal radiography. Factors associated with VC using CT were age, cardiovascular risk factors, vascular comorbidity, microalbuminuria and levels of FGF23, phosphorus and calcium x phosphorus product (CaxP); although only age (OR 1.25, 95% CI 1.11 to 1.41), smoking (OR 21.2, CI 4.4 to 100) and CaxP (OR 1.21, CI 1.06 to 1.37) maintained the association in a multivariate analysis. By contrast, only age (OR 1.35, 95% CI 1.07 to 1.74), CaxP (OR 1.14, CI 1.13 to 1.92) and FEP (OR 1.07,95% CI 1004 to 1.14) were associated with abnormal VC in the lateral abdominal radiography. In conclusion, in patients with stage 3 CKD, the detection of VC by abdominal CT is more sensitive than conventional X-rays. Moreover, CaxP is associated with cardiovascular risk factors and vascular comorbidity; quantification of FEPi in these patients provides additional clinical information in advanced VC detected by KI.

Carga de enfermedad atribuible al tabaquismo en Chile / Disease burden attributable to smoking in Chile

Objetivo: El objetivo inicial del proyecto, comenzado en el año 2005, fue seleccionar y desarrollar el marco metodológico más adecuado, así como elaborar un modelo económico común, con el fin de estimar la carga de enfermedad relacionada con el tabaquismo y la costo-efectividad de las intervenciones para controlar la epidemia del tabaco en América Latina.En este reporte se presentan los detalles del modelo económico, el proceso de calibración y validación para adecuarlo a la realidad de Chile y los resultados de carga de enfermedad atribuible al tabaquismo, medida tanto en términos de salud como económicos. Materiales e Métodos: Se describen a continuación los siguientes puntos relacionados con el desarrollo y utilización del modelo económico: 1) Etapa inicial de diagnóstico de situación, 2) Descripción del modelo, 3) Metodología utilizada para la selección de fuentes de información e incorporación de parámetros, 4) Proceso de calibración y validación, 5) Estimación de carga de enfermedad, 6) Aspectos metodológicos de los datos epidemiológicos considerados, y 7) Características de la información de costos de atención médica requerida para el modelo. Conclusión: En Chile el tabaquismo es responsable de una importante cantidad de muertes prematuras, enfermedad y costos sanitarios. El mayor peso está dado por las enfermedades cardiovasculares, la enfermedad pulmonar obstructiva crónica y el cáncer de pulmón. Su impacto en la mortalidad y en la calidad de vida es responsable en forma directa de la pérdida de 428.588 años de vida (por muerte prematura y discapacidad) cada año y explica el 18,5% de todas las muertes que se producen en el país. El tabaquismo genera además un costo directo anual de más de 1 billón de pesos chilenos. Es esperable que los resultados de este estudio contribuyan a tomar conciencia sobre los efectos del tabaco y sean un soporte para que los responsables de las políticas puedan llevar adelante intervenciones para reducir su consumo, lograr la implementación de mayores impuestos al tabaco e instalar las políticas de control promovidas por el Convenio Marco de la Organización Mundial de la Salud para el Control del Tabaco (CMCT-OMS).

Genomics of the proteorhodopsin-containing marine flavobacterium Dokdonia sp. strain MED134.

Proteorhodopsin phototrophy is expected to have considerable impact on the ecology and biogeochemical roles of marine bacteria. However, the genetic features contributing to the success of proteorhodopsin-containing bacteria remain largely unknown. We investigated the genome of Dokdonia sp. strain MED134 (Bacteroidetes) for features potentially explaining its ability to grow better in light than darkness. MED134 has a relatively high number of peptidases, suggesting that amino acids are the main carbon and nitrogen sources. In addition, MED134 shares with other environmental genomes a reduction in gene copies at the expense of important ones, like membrane transporters, which might be compensated by the presence of the proteorhodopsin gene. The genome analyses suggest Dokdonia sp. MED134 is able to respond to light at least partly due to the presence of a strong flavobacterial consensus promoter sequence for the proteorhodopsin gene. Moreover, Dokdonia sp. MED134 has a complete set of anaplerotic enzymes likely to play a role in the adaptation of the carbon anabolism to the different sources of energy it can use, including light or various organic matter compounds. In addition to promoting growth, proteorhodopsin phototrophy could provide energy for the degradation of complex or recalcitrant organic matter, survival during periods of low nutrients, or uptake of amino acids and peptides at low concentrations. Our analysis suggests that the ability to harness light potentially makes MED134 less dependent on the amount and quality of organic matter or other nutrients. The genomic features reported here may well be among the keys to a successful photoheterotrophic lifestyle.

Expression of ice, bcl-2, c-myc and p53 in different bone marrow cell populations from patients with diffuse large B-cell lymphoma.

We have previously reported functional alterations in vitro in the hematopoietic compartment of patients with diffuse large B-cell lymphoma (DLBCL). In the present study, we assessed the presence of molecular alterations in hematopoietic cells derived from DLBCL marrow. Accordingly, the expression of four genes (i.e. ice, bcl-2, c-myc and p53) was assessed both, at the mRNA and protein levels, in three cell populations: (i) population I, consisting of morphologically recognizable precursor and mature cells; (ii) population II, enriched for CD34+ Lineage-negative (Lin-) cells; and (iii) population III, enriched for CD34+ CD38- Lin- cells. By using a multiplex reverse transcriptase-polymerase chain reaction system, we observed reduced expression of bcl-2 in population I, and c-myc in populations I and II from lymphoma marrow compared to their normal counterparts. On the other hand, expression of ice and p53 was not significantly different when comparing normal and DLBCL samples. At the protein level, all four molecules were expressed in a higher proportion of samples from DLBCL patients than in marrow samples from normal subjects. Interestingly, these proteins were expressed predominantly in primitive cells (population III), whereas the proportion of positive samples was reduced in population II, and even more in population I. Taken together, our results indicate that, in DLBCL, molecular alterations are present in hematopoietic cells from bone marrow, including morphologically recognizable precursor and mature cells, as well as primitive hematopoietic progenitors (CD34+ cells). To date, the physiological implications of these alterations are still unclear, and further studies should be undertaken to address this issue.

[Diffuse large cell lymphoma: new molecular approaches]. / El linfoma difuso de células grandes: nuevos enfoques moleculares.

The term lymphoma comprises a group of neoplasias that develop within the lymphatic system and represent one of the most frequent types of cancer worldwide. During the last decade, significant advances on the molecular biology of lymphoma have been achieved, which have been important not only to understand the etiology of this disease, but also in the development of fast and accurate diagnostic and prognostic methods, which in turn, will allow us to develop appropriate treatments for individual patients. Current systems for the classification of lymphomas have also been influenced by new molecular tools, recently developed. The main goal of this article is to present a general view on the latest advances in the molecular biology of lymphoma. In order to do so, we have focused on Diffuse Large B-Cell Lymphoma (DLBCL), one of the most common, and most studied, types of lymphoma. It is noteworthly that most of what we know about DLBCL arises from studies on lymph nodes, and this is reflected in the present review; however, here we have also included recent information regarding cellular and molecular findings in bone marrow from DLBCL patients. These latter observations may be relevant in opening new lines of research in the near future.

In vitro proliferation and expansion of hematopoietic progenitors from patients with diffuse large B-cell lymphoma before and after chemotherapy.

We have previously demonstrated that when cultured in Dexter-type Long-Term Marrow Cultures (LTMC), hematopoietic progenitor cells (HPC) from patients with Diffuse Large B-Cell Lymphoma (DLBCL) show a defective proliferation, as compared to HPC from normal marrow. In that study it was also demonstrated that functional alterations were present in the hematopoietic microenvironment developed in culture; thus, it was not clear whether such a defective proliferation in vitro was due to an intrinsic defect in the HPC compartment of DLBCL patients, or to an altered microenvironment, or both. In order to address this question, in the present study we have assessed the proliferation and expansion potentials of HPC present in bone marrow from patients with DLBCL, in cytokine-supplemented liquid cultures initiated with a cell population enriched for CD34+ Lin- cells, in the absence of stromal cells and in the presence of reduced numbers of accessory cells. Our results demonstrated that bone marrow-derived HPC from patients with DLBCL, both before and right after chemotherapy, possessed reduced proliferation and expansion potentials in vitro, as compared to their normal counterparts. Interestingly, in patients analyzed 18 months after treatment the proliferation and expansion levels were similar to those of normal HPC, indicating a complete restoration of the hematopoietic function. Although the reason for these observations is not clear, our results suggest the possibility that primitive CD34+ progenitor cells present in bone marrow, which show deficient proliferation and expansion potentials in vitro, are involved in the origin/progression of DLBCL.