Carlos Santonja

A molecular risk score based on 4 functional pathways for advanced classical Hodgkin lymphoma

Despite improvement in the treatment of advanced classical Hodgkin lymphoma, approximately 30% of patients relapse or die as result of the disease. Current predictive systems, determined by clinical and analytical parameters, fail to identify these high-risk patients accurately. We took a multistep approach to design a quantitative reverse-transcription polymerase chain reaction assay to be applied to routine formalin-fixed paraffin-embedded samples, integrating genes expressed by the tumor cells and their microenvironment. The significance of 30 genes chosen on the basis of previously published data was evaluated in 282 samples (divided into estimation and validation sets) to build a molecular risk score to predict failure. Adequate reverse-transcription polymerase chain reaction profiles were obtained from 262 of 282 cases (92.9%). Best predictor genes were integrated into an 11-gene model, including 4 functional pathways (cell cycle, apoptosis, macrophage activation, and interferon regulatory factor 4) able to identify low- and high-risk patients with different rates of 5-year failure-free survival: 74% versus 44.1% in the estimation set (P < .001) and 67.5% versus 45.0% in the validation set (P = .022). This model can be combined with stage IV into a final predictive model able to identify a group of patients with very bad outcome (5-year failure-free survival probability, 25.2%).

MicroRNA signatures and treatment response in patients with advanced classical Hodgkin lymphoma

Although specific microRNA (miRNA) signatures in classical Hodgkin lymphoma (cHL) have been proposed, their relationship with clinical outcome remains unclear. Despite treatment advances, a substantial subset of patients with advanced cHL are refractory to standard therapies based on adriamycin and its variants. Global miRNA expression data of 29 advanced cHL patients and five cHL‐derived cell lines were used to identify profiles from Hodgkin‐Reed‐Sternberg (HRS) cells and their non‐tumoural microenvironment. A cHL‐miRNA signature was identified with 234 miRNAs differentially expressed. A subset of these miRNAs was associated with outcome and selected for study in an independent set of 168 cHL samples using quantitative reverse transcription polymerase chain reaction. Multivariate Cox regression analyses including cross‐validation with failure‐free survival (FFS) as clinical endpoint revealed a miRNA signature with MIR21, MIR30E, MIR30D and MIR92B* that identified two risk‐groups with significant differences in 5‐year FFS (81% vs. 35·7%; P < 0·001). Additionally, functional silencing of MIR21 and MIR30D in L428 cells showed increased sensitivity to doxorubicin‐induced apoptosis, pointing towards abnormalities of mitochondrial intrinsic and TP53‐CDKN1A pathways as related to miRNA deregulation in cHL. These results suggest that clinical outcome in cHL is associated with a specific miRNA signature. Moreover, functional analyses suggest a role for MIR21 and MIR30D in cHL pathogenesis and therapeutic resistance.

Immunohistochemistry in Dermatopathology: A Review of the Most Commonly Used Antibodies (Part II)

Dermatopathology includes a long list of disorders, some of which have very similar histopathology. Immunohistochemistry is an important auxiliary tool for diagnosis and differential diagnosis, and for predicting the outcome of many skin tumors. It is also the main technique for determining the origin of a tissue or the differentiation of neoplastic cells. In many cases, immunohistochemistry provides a more accurate diagnosis of the different processes that infiltrate the skin. This review examines the role of immunohistochemistry in studying the differentiation and biological behavior of the majority of tumors that can involve the skin. We review the immunoperoxidase techniques, discuss the utility of the most commonly used antibodies, and highlight a number of diagnostic problems in which immunohistochemistry may be very useful. In each case, the goal is to reach a specific and definitive diagnosis. In the first part of this review, we examine the antibodies that determine the different cell-differentiation profiles of skin tumors.

Primary cutaneous follicular helper T‐cell lymphoma

Follicular helper T‐cells (TFH) represent a specific subset of CD4‐positive helper T‐cells that help B‐cells to differentiate into long‐lived antibody‐secreting plasma cells or memory B‐cells. The expression of TFH markers in neoplastic T‐cells, traditionally related to the angioimmunoblastic (AITL) subgroup of peripheral T‐cell lymphomas, is nowadays well‐known to be more widespread than previously thought. We report hereby a case of cutaneous T‐cell lymphoma in a 75‐year‐old woman, whose morphological and immunophenotypical features raises the differential diagnosis between cutaneous involvement by AITL and the recently described primary cutaneous T‐cell lymphoma with follicular helper‐phenotype.

Immunohistochemistry in Dermatopathology: A Retrospective Study of the Most Frequently Used Antibodies.

Abstract:Immunohistochemistry (IHC) is an ancillary technique to improve diagnostic accuracy and prognosis in histopathology of both inflammatory and neoplastic cutaneous disorders. However, only a few studies address specifically the set of antibodies available for inflammatory or neoplastic skin diseases. In this study, we analyzed the IHC studies performed for inflammatory and neoplastic skin disorders in cutaneous biopsies taken in our department during 1 year. From a total of 8579 skin biopsies performed throughout the year 2011 in our department, IHC studies were performed in 283 cutaneous biopsies. The total number of different antibodies used in the IHC studies of those 283 skin biopsies was 129. These antibodies were used in 1421 studies, with a mean of 5 cases per antibody studied. The proliferative marker MIB-1 was the single antibody with the highest number of studies, with a total of 119 (8.3% of all IHC studies performed), followed by 113 of CD3 (7.9% of total IHC studies) and 108 of Melan-A (7.6% of total IHC studies). Other hematopoietic differentiation markers, such as CD20, CD4, and CD8, and other melanocytic markers, such as S-100 protein, Melan-A, and HMB-45, were all investigated with a frequency greater than 50 studies each. The 2 most frequent categories were melanocytic neoplasms, which represented 25% of all specimens studied by IHC, and the proliferations of lymphohematopoietic nature, which were 20% of all studied samples and represented by far the highest number of IHC stains per case to reach a final diagnosis. Both previous categories together accounted for 45% of all diagnoses in which IHC was performed. We compare our results with the only similar study previously published in the literature. The gold standard panel of antibodies that should be available in everyday practice in dermatopathology to arrive at a specific diagnosis in each cutaneous inflammatory disease or neoplastic process involving the skin is still a matter of discussion.

Cutaneous pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma FOSB immunohistochemistry demonstrating the SERPINE1-FOSB fusion gene

Pseudomyogenic hemangioendothelioma is a distinctive vascular neoplasm characterized by a multicentric presentation that mostly involves the lower extremities of young adults. Histopathologic resemblance to epithelioid sarcoma and co-expression of both keratins and endothelial markers are its hallmarks. A specific SERPINE1-FOSB fusion gene derived from t(7;19)(q22;q13) with significantly higher FOSB mRNA expression in neoplastic cells is the characteristic cytogenetic anomaly of this tumor. This article is protected by copyright. All rights reserved.

MYD88 L265P mutation in cutaneous involvement by Waldenström macroglobulinemia

Cutaneous manifestations of Waldenström macroglobulinemia (WM) may occur because of several mechanisms, the least common being direct skin infiltration by neoplastic cells. We report a case of patient that after 4‐year history of indolent WM developed skin infiltration by lymphoplasmacytoid cells in the form of a small, mildly indurated plaque on the anterior chest. MYD88 L265P mutation was detected both in the previous bone marrow biopsy and in the cutaneous lesion. We review the impact of this new genetic tool in the diagnosis and treatment of lymphoplasmacytic proliferations.

De Novo CD5-Positive Diffuse Large B-Cell Lymphoma Report of a Case Presenting With Cutaneous Involvement and Featuring Extensive Intravascular Dissemination on Postmortem Examination

De novo CD5-positive diffuse large B-cell lymphoma (DLBCL) represents 10% of DLBCLs and is frequently associated with an aggressive clinical course and poor response to chemotherapy. We report a case of an 84-year old man who presented with cutaneous lesions, malaise, and B-symptoms. A skin biopsy revealed neoplastic cells within the lumen of dermal vessels. The patient deteriorated rapidly and died. On postmortem examination, lymphadenopathy with diffuse effacement of lymph node architecture, widespread intravascular neoplastic cells in the skin, lungs, gastrointestinal tract, adrenal glands, testes, and kidneys; and rare, isolated neoplastic cells within vessels of liver and central nervous system were noted. Intravascular or intrasinusoidal invasion has been previously reported in earlier series of de novo CD5-positive DLBCL, but is not a widely recognized phenomenon, and requires differentiation from other lymphomas sharing this histopathologic feature.

Mycosis fungoides progression could be regulated by microRNAs

Differentiating early mycosis fungoides (MF) from inflammatory dermatitis is a challenge. We compare the differential expression profile of early-stage MF samples and benign inflammatory dermatoses using microRNA (miRNA) arrays. 114 miRNAs were found to be dysregulated between these entities. The seven most differentially expressed miRNAs between these two conditions were further analyzed using RT-PCR in two series comprising 38 samples of early MFs and 18 samples of inflammatory dermatitis. A series of 51 paraffin-embedded samples belonging to paired stages of 16 MF patients was also analyzed. MiRNAs 26a, 222, 181a and 146a were differentially expressed between tumoral and inflammatory conditions. Two of these miRNAs (miRNA-181a and miRNA-146a) were significantly deregulated between early and advanced MF stages. Bioinformatic analysis showed FOXP3 expression to be regulated by these miRNAs. Immunohistochemistry revealed the level of FOXP3 expression to be lower in tumoral MFs than in plaque lesions in paraffin-embedded tissue. A functional study confirmed that both miRNAs diminished FOXP3 expression when overexpressed in CTCL cells. The data presented here suggest that the analysis of a restricted number of miRNAs (26a, 222, 181a and 146a) could be sufficient to differentiate tumoral from reactive conditions. Moreover, these miRNAs seem to be involved in MF progression.

Analysis of the mutational landscape of classic Hodgkin lymphoma identifies disease heterogeneity and potential therapeutic targets

Defining the mutational landscape of classic Hodgkin lymphoma is still a major research goal. New targeted next-generation sequencing (NGS) techniques may identify pathogenic mechanisms and new therapeutic opportunities related to this disease. We describe the mutational profile of a series of 57 cHL cases, enriched in Hodgkin and Reed-Sternberg (HRS) cells. Overall, the results confirm the presence of strong genomic heterogeneity. However, several variants were consistently detected in genes related to relevant signaling pathways, such as GM-CSF/IL-3, CBP/EP300, JAK/STAT, NF-kappaB, and numerous variants of genes affecting the B-cell receptor (BCR) pathway, such as BTK, CARD11, BCL10, among others. This unexpectedly high prevalence of mutations affecting the BCR pathway suggests some requirement for active BCR signaling for cHL cell viability. Additionally, incubation of a panel of cHL cellular models with selective BTK inhibitors in vitro constrains cell proliferation and causes cell death. Our results indicate new pathogenic mechanisms and therapeutic opportunities in this disease.