Recent Advances in Genitourinary Tumors Updates From the 5th Edition of the World Health Organization Blue Book Series

CONTEXT.—

Urinary and Male Genital Tumours is the 8th volume of the World Health Organization Classification of Tumours series, 5th edition. Released in hard copy in September 2022, it presents an update to the classification of male genital and urinary tumors in the molecular age. Building upon previous volumes in this series, significant effort has been made to harmonize terminology across organ systems for biologically similar tumors (eg, neuroendocrine tumors). Genomic terminology has been standardized and genetic syndromes covered more comprehensively. This review presents a concise summary of this volume highlighting new entities, notable modifications relative to the 4th edition, and elements of relevance to routine clinical practice.

OBJECTIVE.—

To provide a comprehensive update on the World Health Organization classification of urinary and male genital tumors, highlighting updated diagnostic criteria and terminology.

DATA SOURCES.—

The 4th and 5th editions of the World Health Organization Classification of Tumours: Urinary and Male Genital Tumours.

CONCLUSIONS.—

The World Health Organization has made several changes in the 5th edition of the update on urinary and male genital tumors that pathologists need to be aware of for up-to-date clinical practice.

The changing landscape of pediatric histiocytoses: Birth, life, and transdifferentiation of pediatric histiocytes

Histiocytic neoplasms in the children are very rare, and histiocytoses can occur in the perinatal period. The presumed origins and presentation of specific histiocytoses in the pediatric age group are described. Common and newly described histiocytoses are presented including Langerhans cell histiocytosis, Rosai-Dorfman disease, histiocytic sarcoma, ALK positive histiocytosis, and hemophagocytic lymphohistiocytosis. Molecular findings common to pediatric histiocytoses are also discussed.

Controversies in the Spleen: Histiocytic, Dendritic, and Stromal Cell Lesions

Histiocytic, dendritic, and stromal cell lesions that occur in the spleen are challenging diagnostically, not well studied due to their rarity, and therefore somewhat controversial. New techniques for obtaining tissue samples also create challenges as splenectomy is no longer common and needle biopsy does not afford the same opportunity for examination of tissue. Characteristic primary splenic histiocytic, dendritic, and stromal cell lesions are presented in this paper with new molecular genetic findings in some entities that help differentiate these lesions from those occurring in non-splenic sites, such as soft tissue, and identify possible molecular markers for diagnosis.

Top Ten Lymphoproliferative Lesions Not to Miss When Evaluating Oral Ulcer Biopsies

BACKGROUND

Oral ulcers represent a full thickness loss of the mucosal epithelium leading to exposure of the submucosal connective tissue. These are common and usually self-limited lesions, although they may sometimes result from neoplasms, most commonly squamous cell carcinoma. Lymphoproliferative disorders may be difficult to diagnose in apthous ulcers since they mimic reactive inflammation.

METHODS

This review presents ten rare oral lymphoid proliferations which should not be missed when assessing oral ulcer biopsies.

RESULTS

The ten lesions include several with diagnostic cells which look similar to the histiocytes of a reactive inflammatory ulcer, including Rosai-Dorfman disease, reticulohistiocytoma, Langerhans cell histiocytosis, and traumatic ulcerative granuloma. Other lesions, such as EBV-positive mucocutaneous ulcer, extranodal marginal zone lymphoma of mucosal-associated lymphoid tissue, and plasmablastic lymphoma have lymphoid and/or plasma cell differentiation that mimic the reactive lymphocytes and plasma cells found in reactive ulcers. Two dendritic cell lesions, follicular dendritic cell sarcoma and blastic plasmacytoid dendritic cell neoplasm, both have distinct phenotypes which are required to make an accurate diagnosis.

CONCLUSION

Each of these lesions are diagnosed by evaluating their histology, along with their phenotypic profile, which is sometimes enhanced by pertinent molecular findings.

The Reemergence of Measles

OBJECTIVES

Present-day pathologists may be unfamiliar with the histopathologic features of measles, which is a reemerging disease. Awareness of these features may enable early diagnosis of measles in unsuspected cases, including those with an atypical presentation. Using archived tissue samples from historic patients, a unique source of histopathologic information about measles and other reemerging infectious diseases, we performed a comprehensive analysis of the histopathologic features of measles seen in commonly infected tissues during prodrome, active, and late phases of the disease.

METHODS

Subspecialty pathologists analyzed H&E-stained slides of specimens from 89 patients accessioned from 1919 to 1998 and correlated the histopathologic findings with clinical data.

RESULTS

Measles caused acute and chronic histopathologic changes, especially in the respiratory, lymphoid (including appendix and tonsils), and central nervous systems. Bacterial infections in lung and other organs contributed significantly to adverse outcomes, especially in immunocompromised patients.

CONCLUSIONS

Certain histopathologic features, especially Warthin-Finkeldey cells and multinucleated giant cells without inclusions, allow pathologists to diagnose or suggest the diagnosis of measles in unsuspected cases.

Algorithmic Approach to the Splenic Lesion Based on Radiologic-Pathologic Correlation

Splenic lesions are commonly discovered incidentally at imaging, without clinical signs or symptoms that may aid in diagnosis. As such, the differential diagnosis and subsequent management are based primarily on imaging characteristics. Much has been written about the myriad pathologic conditions that can occur in the spleen; however, there is little guidance on the approach to an incidental splenic mass. Applying an approach frequently used in imaging to the splenic mass-based on the number and consistency of lesions and refined by supplementary imaging features-allows formulation of a useful differential diagnosis. Solitary cystic masses include true cysts, pseudocysts, and parasitic cysts. When multiple cystic lesions are present, the differential diagnosis expands to include infectious lesions (abscess or microabscesses) and lymphangioma (a benign cystic neoplasm). Hemangioma is the most common solitary solid mass, although other vascular lesions (hamartoma, sclerosing angiomatoid nodular transformation) and nonvascular lesions (inflammatory pseudotumor, lymphoma) manifest as solitary and solid. When multiple solid masses are present, diffuse inflammatory disease (sarcoidosis), littoral cell angioma, and lymphoma should be considered. Malignancies, such as angiosarcoma or metastasis, can manifest as solitary or multiple and solid or cystic masses but are typically associated with symptoms or widespread primary malignancy. Careful assessment of the multimodality imaging characteristics of splenic lesions based on this approach aids the radiologist faced with the incidental splenic lesion. Online supplemental material is available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

Intravascular Large B-Cell Lymphoma

CONTEXT.—

Intravascular large B-cell lymphoma (IVLBCL) is a rare hematopathologic entity, posing both a clinical and histologic challenge for diagnosis. Numerous pitfalls can hinder making the diagnosis.

OBJECTIVE.—

To summarize recent developments in literature pertaining to IVLBCL and point out key pitfalls pathologists should be prepared to encounter.

DATA SOURCES.—

Literature review via PubMed search and hospital (Darnall Medical Library) resources.

CONCLUSIONS.—

The 3 primary pitfalls of IVLBCL include masking of IVLBCL, mimicry by IVLBCL, and mimicry of IVLBCL. These scenarios illustrate the importance of histologic pattern recognition and subsequent usage of immunohistochemistry, especially in context of a clinical history that may be noncharacteristic.

CD5-Negative, CD10-Negative Low-Grade B-Cell Lymphoproliferative Disorders of the Spleen

CD5-negative, CD10-negative low-grade B-cell lymphoproliferative disorders (CD5-CD10-LPD) of the spleen comprise a fascinating group of indolent, neoplastic, mature B-cell proliferations that are essential to accurately identify but can be difficult to diagnose. They comprise the majority of B-cell LPDs primary to the spleen, commonly presenting with splenomegaly and co-involvement of peripheral blood and bone marrow, but with little to no involvement of lymph nodes. Splenic marginal zone lymphoma is one of the prototypical, best studied, and most frequently encountered CD5-CD10-LPD of the spleen and typically involves white pulp. In contrast, hairy cell leukemia, another well-studied CD5-CD10-LPD of the spleen, involves red pulp, as do the two less common entities comprising so-called splenic B-cell lymphoma/leukemia unclassifiable: splenic diffuse red pulp small B-cell lymphoma and hairy cell leukemia variant. Although not always encountered in the spleen, lymphoplasmacytic lymphoma, a B-cell lymphoproliferative disorder consisting of a dual population of both clonal B-cells and plasma cells and the frequent presence of the MYD88 L265P mutation, is another CD5-CD10-LPD that can be seen in the spleen. Distinction of these different entities is possible through careful evaluation of morphologic, immunophenotypic, cytogenetic, and molecular features, as well as peripheral blood and bone marrow specimens. A firm understanding of this group of low-grade B-cell lymphoproliferative disorders is necessary for accurate diagnosis leading to optimal patient management.

Recent Advances in Digestive Tract Tumors: Updates From the 5th Edition of the World Health Organization "Blue Book"

CONTEXT.—

The World Health Organization Classification of Tumours: Digestive System Tumors, 5th edition, was published in 2019 and shows several impactful changes as compared with the 4th edition published in 2010. Changes include a revised nomenclature of serrated lesions and revamping the classification of neuroendocrine neoplasms. Appendiceal goblet cell adenocarcinoma is heavily revised, and intrahepatic cholangiocarcinoma is split into 2 subtypes. New subtypes of colorectal carcinoma and hepatocellular carcinoma are described. Precursor lesions are emphasized with their own entries, and both dysplastic and invasive lesions are generally recommended to be graded using a 2-tier system. Hematolymphoid tumors, mesenchymal tumors, and genetic tumor syndromes each have their own sections in the 5th edition. New hematolymphoid lesions include monomorphic epitheliotropic intestinal T-cell lymphoma; duodenal-type follicular lymphoma; intestinal T-cell lymphoma, not otherwise specified; and indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. This paper will provide an in-depth look at the changes in the 5th edition as compared with the 4th edition.

OBJECTIVE.—

To provide a comprehensive, in-depth update on the World Health Organization classification of digestive tumors, including changes to nomenclature, updated diagnostic criteria, and newly described entities.

DATA SOURCES.—

The 5th edition of the World Health Organization Classification of Tumours: Digestive System Tumours, as well as the 4th edition.

CONCLUSIONS.—

The World Health Organization has made many key changes in its newest update on tumors of the digestive system. Pathologists should be aware of these changes and incorporate them into their practice as able or necessary.

Overview of Gastrointestinal Lymphoproliferative disorders✰

Lymphoproliferative processes which occur in the gastrointestinal tract range from benign reactive processes such as follicular hyperplasia (rectal tonsil) to high grade malignant lymphomas and histiocytic sarcoma. The WHO Classification of Tumors: Digestive System Tumors, 5th Edition was published in 2019 and shows several impactful changes as compared to the 4th Edition published in 2010. WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues 2017 also included detailed changes in hematopoietic neoplasms within the gastrointestinal tract. New entities or renamed hematolymphoid lesions include monomorphic epitheliotropic intestinal T-cell lymphoma, duodenal-type follicular lymphoma, intestinal T-cell lymphoma, NOS and indolent T-cell lymphoproliferative disorder of the gastrointestinal tract. A brief overview of WHO classification of digestive tumors and WHO classification of tumors of hematopoietic and lymphoid tissue is discussed focusing on the changes in the most recent WHO texts. In depth discussions will be presented in other papers in this series.

Pediatric Lymphoid and Histiocytic Lesions in the Head and Neck

Lymphoid and histiocytic lesions of the head and neck in pediatric patients is a fascinating topic as most of these lesions are benign, but that the neoplastic cases are essential to diagnose accurately for appropriate treatment. It is thought that 90% of children will have palpable lymph nodes between the ages of 4 to 8; most, but not all, are non-malignant and some resolve spontaneously without treatment. This paper will look at many of the benign and malignant lesions of both lymphocytic and histiocytic origin that present in the head and neck of children focusing on their diagnostic criteria. There is a very pertinent discussion of nonmalignant lymphoid proliferations, as infections and other reactive conditions dominate the pathology of pediatric lymphohistiocytic head and neck lesions. Discussion of those lymphomas which arise more frequently in the head and neck focuses on those seen in children and young adults such as classic Hodgkin lymphoma and Burkitt lymphoma, as well as new more controversial entities such as pediatric-type follicular lymphoma. Histiocytic lesions, both benign and malignant, are described and may be challenging to diagnose.

0226 Sleep Duration and Symptoms Associated with Race/Ethnicity in Elite Collegiate Athletes

Introduction

Previous studies have documented sleep disparities in the general population. Given the increased interest in sleep among athletes, and the degree to which demographics and schedules among athletes differ from the general population, this analysis aims to examine the relationship between race/ethnicity and sleep duration and symptoms among elite college athletes.

Methods

Data were obtained from N=189 Division-1 collegiate athletes across a wide range of sports played. Race/ethnicity was self-reported and categorized as Non-Hispanic White, Black/African-American, Hispanic/Latino, Asian, and American Indian/Alaskan Native. Outcomes of interest included self-reported typical sleep duration (in hours), CESD depression score, and frequency of sleep symptoms, assessed using items from the Sleep Disorders Symptom Check List (difficulty falling asleep, difficulty staying asleep, early morning awakenings, tiredness, sleepiness, loud snoring, choking/gasping, fragmentation, hypnogogic/pompic hallucinations, sleep paralysis, and nightmares). Sleep duration and depression were evaluated with linear regression, and symptoms were evaluated as ordinal. Covariates included age and sex.

Results

Compared to Non-Hispanic Whites, Blacks/African-Americans reported less sleep (B=-0.80, p<0.0005), more depression (B=2.85, p=0.046), more difficulty maintaining sleep (oOR=2.12, p=0.034), early morning awakenings (oOR=3.15, p=0.001), and sleepiness (oOR=2.11, p=0.048); Hispanic/Latinos reported more hypnogogic/pompic hallucinations (oOR=2.90, p=0.007), sleep paralysis (oOR=2.72, p=0.026), and nightmares (oOR=2.22, p=0.035); Asians reported more depression (B=4.46, p=0.028), sleepiness (oOR=5.06, p=0.003), loud snoring (oOR=4.71, p=0.018), and sleep paralysis (oOR=3.57, p=0.031); and American Indians/Alaskan Natives reported less sleep (B=-1.00, p=0.018).

Conclusion

Racial/ethnic differences in sleep duration and sleep symptoms were seen among athletes. Future studies will be needed to replicate and further explain these findings.

Support

The REST study was funded by an NCAA Innovations grant. Dr. Grandner is supported by R01MD011600

0240 College Football Players Compared to Other Collegiate Athletes: Symptoms of Insufficient Sleep Duration, Insomnia, and Sleep Apnea

Introduction

College athletes experience frequent sleep disturbances. Data from professional football players suggests high rates of sleep apnea symptoms. Little data is available on college football players, especially compared to other athletes.

Methods

Data were obtained from N=189 NCAA Division-I student athletes, including N=45 football players). Outcomes of interest came from the Sleep Disorders Symptom Check List (SDSCL) which rated symptoms on a frequency scale of 0: never and 4: >5 times/week. Symptoms evaluated were daytime tiredness, any snoring, loud snoring, breathing pauses during sleep, and waking up choking/gasping sleep apnea), as well as difficulty falling asleep, difficulty with nighttime awakenings, and early morning awakenings (insomnia). Other outcomes include self-reported sleep duration, Insomnia Severity Index, frequency of caffeine use, and frequency of use of medications to help with sleep. Linear and ordinal logistic regression analyses were adjusted for age, sex, year in school, socioeconomic status, and mood. Post-hoc analyses examined men only.

Results

Regarding sleep apnea symptoms, football players reported more snoring (oOR=3.14, p=0.01), loud snoring (oOR=4.38, p=0.008), breathing pauses (oOR=5.42, p=0.0499), and choking/gasping (oOR=8.51), but not daytime tiredness. Regarding insufficient sleep, football players reported no difference in sleep duration but decreased caffeine use (oOR=0.27, p=0.002). Regarding insomnia, football players showed no difference in ISI scores or insomnia symptoms, but increased likelihood of sleeping pill use (oOR=3.01, p=0.03). When analyses were restricted to men only, all of these relationships were maintained.

Conclusion

College football athletes may exhibit different sleep symptoms than other college athletes, as they exhibit more sleep apnea-related symptoms, without the increase in daytime symptoms, such as tiredness.

Support

The REST study was funded by an NCAA Innovations grant.

Dr. Grandner is supported by R01MD011600

0236 Team-Based Athletes Sleep Less Than Individual Athletes, But Do Not Report More Insomnia or Fatigue

Introduction

Collegiate student-athletes face challenges balancing academics and athletics, and getting an adequate amount of sleep is one factor that can assist in sustaining an elite level of play. Team-based sports may present with systematically different sets of demands.

Methods

Data were obtained at the start of the academic semester from N=189 NCAA Division-1 athletes from a wide range of sports. The sample was 46% female. Individuals were classified as playing in a team sport (e.g., football, basketball, baseball, softball, volleyball) or an individual sport (e.g., swimming, track, golf). Sleep-related outcomes included self-reported sleep duration and sleep latency, frequency of sleeping pill use (Never, Rarely, Sometimes, Often), Insomnia Severity Index score, and Fatigue Severity Scale score. Regression analyses were adjusted for age and sex.

Results

In adjusted analyses, team-based athletes reported 22.4 minutes less sleep than individual athletes (95%CI -42.8,-1.9; p<0.05). They also reported 5.6 less minutes of sleep latency (95%CI -10.8,-0.3; p<0.05). More frequent sleeping pill use was also reported (oOR=0.96; 95%CI: 0.26,1.67; p=0.007). They did not report any differences in insomnia or daytime fatigue levels.

Conclusion

These results suggest that even though team-based athletes may not report more sleep complaints or daytime complaints, they may be at increased risk for less sleep and more sleep medication. Further work is needed to identify the sources of these differences to guide interventions.

Support

The REST study was funded by an NCAA Innovations grant.

Dr. Grandner is supported by R01MD011600

T-cell lymphoproliferative processes in the spleen

T-cell lymphoproliferative processes in the spleen are rare and it is important to study normal T cell subsets in the spleen to understand the splenic milieu in which they arise. True malignant T-cell processes including hepatosplenic T-cell lymphoma and T-cell large granular lymphocytic leukemia occur in the spleen, but other atypical reactive T-cell proliferations and those of uncertain significance also have been described. Proper distinction of florid T cell responses from malignant T-cell neoplasms has important therapeutic implications for the patient.

Effects of neratinib on health-related quality of life in women with HER2-positive early-stage breast cancer: longitudinal analyses from the randomized phase III ExteNET trial

BACKGROUND

We report longitudinal health-related quality-of-life (HRQoL) data from the international, randomized, double-blind, placebo-controlled phase III ExteNET study, which demonstrated an invasive disease-free survival benefit of extended adjuvant therapy with neratinib over placebo in human epidermal growth factor receptor-2-positive early-stage breast cancer.

PATIENTS AND METHODS

Women (N  = 2840) with early-stage HER2-positive breast cancer who had completed trastuzumab-based adjuvant therapy were randomly assigned to neratinib 240  mg/day or placebo for 12  months. HRQoL was an exploratory end point. Patients completed the Functional Assessment of Cancer Therapy-Breast (FACT-B) and EuroQol 5-Dimensions (EQ-5D) questionnaires at baseline and months 1, 3, 6, 9, and 12. Changes from baseline were compared using analysis of covariance with no imputation for missing values. Sensitivity analyses used alternative methods. Changes in HRQoL scores were regarded as clinically meaningful if they exceeded previously reported important differences (IDs).

RESULTS

Of the 2840 patients (intention-to-treat population), 2407 patients were evaluable for FACT-B (neratinib, N  = 1171; placebo, N  = 1236) and 2427 patients for EQ-5D (neratinib, N  = 1186; placebo, N  = 1241). Questionnaire completion rates exceeded 85%. Neratinib was associated with a decrease in global HRQoL scores at month 1 compared with placebo (adjusted mean differences: FACT-B total, -2.9 points; EQ-5D index, -0.02), after which between-group differences diminished at later time-points. Except for the FACT-B physical well-being (PWB) subscale at month 1; all between-group differences were less than reported IDs. The FACT-B breast cancer-specific subscale showed small improvements with neratinib at months 3-9, but all were less than IDs. Sensitivity analyses exploring missing data did not change the results.

CONCLUSIONS

Extended adjuvant neratinib was associated with a transient, reversible decrease in HRQoL during the first month of treatment, possibly linked to treatment-related diarrhea. With the exception of the PWB subscale at month 1, all neratinib-related HRQoL changes did not reach clinically meaningful thresholds. ClinicalTrials.gov: NCT00878709.

Practical Applications in Immunohistochemistry: An Immunophenotypic Approach to the Spleen

CONTEXT.—

Even though immunohistochemistry is routinely used by pathologists, evaluation of immunohistochemistry in splenic lesions remains difficult for many. Classification of benign and splenic lesions often requires a combination of hematoxylin-eosin evaluation, immunophenotyping, and sometimes molecular testing. Immunohistochemical staining is essential in evaluating many splenic lesions, and requires an understanding of the normal compartments of the spleen.

OBJECTIVE.—

To address different immunohistochemical features used for identification and subclassification of different lesions of the spleen, as well as in the normal compartments of the spleen.

DATA SOURCES.—

The information outlined in this review article is based on our experiences with a variety of spleen cases, on the current World Health Organization classification of hematopoietic and lymphoid tumors, and on a review of English-language articles published during 2018.

CONCLUSIONS.—

Features for phenotyping normal spleen as well as a variety of splenic lesions, including littoral cell angioma and splenic marginal zone lymphoma, are discussed. Suggested immunopanels are provided to assist in the diagnosis of different lesions of the spleen.

Abstract P1-13-08: Extended adjuvant neratinib/fulvestrant blocks ER/HER2 crosstalk and maintains complete responses of ER+/HER2+ tumors following treatment with chemotherapy and anti-HER2 therapy

Background: Neratinib is a potent, irreversible pan-HER tyrosine kinase inhibitor. The phase III trial ExteNET showed improved disease-free survival in patients (pts) with HER2+ breast cancer treated with neratinib vs placebo after trastuzumab-based adjuvant therapy. The benefit from neratinib appeared to be greater in pts with ER+ tumors. Thus, we sought to elucidate mechanisms that may explain the benefit from extended adjuvant therapy with neratinib in pts with ER+/HER2+ breast cancer using a human-in-mouse model that simulates the clinical outcomes seen in ExteNET.

Results: Mice with established ER+/HER2 amplified MDA-361 tumors were treated with trastuzumab (tz) + paclitaxel (pac) for 4 weeks, and then randomized to fulvestrant (fulv) ± neratinib for 4 weeks. All MDA-361 tumors exhibited a prompt and marked reduction in volume after tz/pac treatment; 10 mice achieved a complete response (CR) before receiving 'extended adjuvant' therapy with fulv (n=5) or neratinib/fulv (n=5). A CR was maintained with neratinib/fulv following tz/pac. However, mice treated with fulv alone, relapsed rapidly (p<0.05 at week 8) despite of a complete downregulation of tumor ER levels. In a second experiment, nude mice with established MDA-361 xenografts were treated with pertuzumab/tz/pac for 4 weeks. Following a CR, mice were randomized to neratinib/fulv vs. fulv. Again, mice treated with neratinib/fulv maintained a CR, while mice in the fulv alone arm exhibited tumor progressions within a week. In three ER+/HER2+ cell lines (MDA-361, BT474 and UACC893) but not in ER+/HER– MCF7 cells, treatment with neratinib induced ER reporter transcriptional activity whereas treatment with fulv resulted in an increase in HER2 phosphorylation, suggesting compensatory crosstalk between the ER and HER2 pathways. To further understand the molecular basis of this crosstalk, MDA-361 tumor-bearing mice were treated with either fulv, neratinib or the combination for 7 days, after which tumors were harvested and analyzed using a Nanostring breast cancer ER panel consisting of 196 ER-regulated genes. Compared to vehicle or fulv-treated tumors, tumors treated with neratinib alone and neratinib/fulv showed marked downregulation of cyclin D1 mRNA expression. Similarly, in MDA-361, BT474 and UACC893 cells but not in MCF7 cells, only neratinib/fulv downregulated cyclin D1, P-AKT and P-ERK. Finally, treatment with neratinib/fulv but not fulv alone reduced cyclin D1 transcriptional reporter activity and cyclin D1 protein levels, and induced cell cycle arrest, suggesting double blockade is required to overcome compensatory crosstalk between ER and amplified HER2.

Conclusions: Neratinib/fulv but not fulv alone maintained complete responses of ER+/HER+ tumors following treatment with tz/pac or pertuzumab/tz/pac, reminiscent of the results in ExteNET. Neratinib treatment promoted ER transcriptional activity whereas ER downregulation with fulv was associated with increased HER2 signaling. In ER+/HER2+ breast cancer cells and tumors, neratinib/fulv synergistically inhibited growth, cyclin D1 expression, and AKT and MAPK activation, thus providing a plausible mechanism to explain the results in the ExteNET trial.

Citation Format: Sudhan DR, Schwarz LJ, Guerrero-Zotano AL, Nixon M, Formisano L, Croessmann S, Gonzalez Ericsson PI, Sanders ME, Balko JM, Avogadri-Connors F, Cutler RE, Lalani AS, Bryce R, Auerbach A, Arteaga CL. Extended adjuvant neratinib/fulvestrant blocks ER/HER2 crosstalk and maintains complete responses of ER+/HER2+ tumors following treatment with chemotherapy and anti-HER2 therapy [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-13-08.

Castleman Disease of the Thorax: Clinical, Radiologic, and Pathologic Correlation: From the Radiologic Pathology Archives

Castleman disease is a complex lymphoproliferative disease pathologically divided into two subtypes, the hyaline vascular variant (HVV) and the plasma cell variant (PCV). The HVV is the most common, is thought to represent a benign neoplasm of lymph node stromal cells, and is treated with surgical resection. It is most commonly found in the mediastinum, where it classically appears as a unicentric, avidly enhancing mass at computed tomography (CT) and magnetic resonance imaging. This appearance can mimic other avidly enhancing mediastinal masses, and location, clinical history, laboratory data, and nuclear medicine single photon emission CT (SPECT) and positron emission tomography (PET) studies can help narrow the differential diagnosis. Multicentric Castleman disease (MCD), which in the majority of cases is composed of the PCV, is an aggressive lymphoproliferative disorder associated with human herpesvirus infection, interleukin 6 dysregulation, and other systemic disorders. While it can be difficult to differentiate MCD from lymphoma, the presence of avidly enhancing lymph nodes can suggest the diagnosis. The purpose of this article is to review the clinical, immunologic, and pathologic findings associated with both unicentric Castleman disease and MCD and discuss how the imaging findings correlate with the pathophysiology of the disease.

Quantum criticality at the superconductor-insulator transition revealed by specific heat measurements

The superconductor–insulator transition (SIT) is considered an excellent example of a quantum phase transition that is driven by quantum fluctuations at zero temperature. The quantum critical point is characterized by a diverging correlation length and a vanishing energy scale. Low-energy fluctuations near quantum criticality may be experimentally detected by specific heat, c_p, measurements. Here we use a unique highly sensitive experiment to measure c_p of two-dimensional granular Pb films through the SIT. The specific heat shows the usual jump at the mean field superconducting transition temperature marking the onset of Cooper pairs formation. As the film thickness is tuned towards the SIT, is relatively unchanged, while the magnitude of the jump and low-temperature specific heat increase significantly. This behaviour is taken as the thermodynamic fingerprint of quantum criticality in the vicinity of a quantum phase transition.

To detect thermodynamic signatures of quantum fluctuations for quantum phase transitions is challenging. Here, Poran et al. report a significant increase in the specific heat when the thickness of granular Pb films approaches a superconductor-insulator transition.

Pathology of Extranodal Lymphoma

An overview of the pathology of extranodal lymphoma is presented. The emphasis of this presentation is on the classification system of extranodal lymphomas, including both B-cell and T-cell lymphomas, based on their morphology, phenotype, and molecular alterations.

Recommendations for gross examination and sampling of surgical specimens of the spleen

This review examines handling and processing of spleen biopsies and splenectomy specimens with the aim of providing the pathologist with guidance in optimizing examination and diagnosis of splenic disorders. It also offers recommendations as to relevant reporting factors in gross examination, which may guide diagnostic workup. The role of splenic needle biopsies is discussed. The International Spleen Consortium is a group dedicated to promoting education and research on the anatomy, physiology, and pathology of the spleen. In keeping with these goals, we have undertaken to provide guidelines for gross examination, sectioning, and sampling of spleen tissue to optimize diagnosis (Burke). The pathology of the spleen may be complicated in routine practice due to a number of factors. Among these are lack of familiarity with lesions, complex histopathology, mimicry within several types of lesions, and overall rarity. To optimize diagnosis, appropriate handling and processing of splenic tissue are crucial. The importance of complete and accurate clinical history cannot be overstated. In many cases, significant clinical history such as previous lymphoproliferative disorders, hematologic disorders, trauma, etc, can provide important information to guide the evaluation of spleen specimens. Clinical information helps plan for appropriate processing of the spleen specimen. The pathologist should encourage surgical colleagues, who typically provide the specimens, to include as much clinical information as possible.

Epstein-Barr virus (EBV)-associated lymphoid lesions of the head and neck

Epstein Barr virus (EBV)-related lymphoproliferative processes occur in the head and neck ranging from reactive processes such as infectious mononucleosis to high grade malignant lymphomas. EBV is a ubiquitous herpes virus that infects more than 90% of adults worldwide, and is generally transferred though saliva. Primary infection can occur throughout life. EBV is the first virus linked to malignancies, both epithelial and lymphoid. Both T and B cell lymphomas can be associated with EBV and evidence shows that an individual's response to the acute EBV infection may be critical in the development of subsequent lymphoma. Currently, in situ hybridization for EBER is the most sensitive available test to detect EBV and should be routinely performed in lymphoproliferative lesions of the head and neck. Immunohistochemistry for EBV related proteins, such as LMP1, is much less sensitive than EBER in situ hybridization, but can help determine latency patterns of EBV infection. Although relatively rare, primary EBV-related lymphomas must be considered in the differential of atypical lymphoid proliferations in the head and neck. We present selected EBV-related disorders of the head and neck discussing etiology as well as differential diagnosis.

Practical Applications in Immunohistochemistry: Evaluation of Diffuse Large B-Cell Lymphoma and Related Large B-Cell Lymphomas

Context

Diffuse large B-cell lymphoma is the most commonly diagnosed subtype of lymphoma worldwide. The current World Health Organization (WHO) classification includes several subtypes, based on a combination of clinical, immunohistochemical, and genetic differences. Immunohistochemical staining is essential in evaluating diffuse large B-cell lymphoma and many related large B-cell lymphomas and aggressive B-cell lymphomas.

Objective

To address different immunohistochemical features used for identification, subclassification, prognosis and in some cases, therapy, of diffuse large B-cell lymphoma and related lymphomas.

Data Sources

The information outlined in this review article is based on our experiences with routine cases, on the current WHO classification of hematopoietic and lymphoid tumors, and on a review of English-language articles published throughout 2014.

Conclusions

Features and diagnostic criteria of diffuse large B-cell lymphoma, aggressive variants of B-cell lymphomas, including Burkitt lymphoma and “double-hit” lymphomas, are discussed. Identification of cell of origin (germinal center type versus activated B-cell type) is discussed at length. Finally, practical approaches for diagnosis are discussed.

The t(14;18)(q32;q21)/IGH-MALT1 translocation in gastrointestinal extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)

AIMS

Studies have indicated that the t(14;18)(q32;q21)/IGH-MALT1 translocation is present in extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT lymphoma). However, only a few studies have investigated the incidence of t(14;18)/IGH-MALT1 in primary gastrointestinal MALT lymphomas or in diffuse large B-cell lymphomas (DLBCL). The overall significance of t(14;18)/IGH-MALT1 in gastrointestinal MALT lymphomas is not clear. We examined 41 gastrointestinal MALT lymphoma and 23 DLBCL cases, with the aim of further understanding the role of t(14;18)/IGH-MALT1 in these diseases.

METHODS AND RESULTS

Fluorescence in-situ hybridization (FISH) assays for the detection of t(14;18)/IGH-MALT1 and t(11;18)(q21;q21)/API2-MALT1, along with immunostaining and histological evaluations, were performed on selected cases. Of the 64 analysed cases, one gastric MALT lymphoma and one colonic MALT lymphoma were positive for t(14;18)/IGH-MALT1.

CONCLUSIONS

We describe what are, to our knowledge, the first reported primary colonic MALT lymphoma carrying t(14;18)(q32;q21)/IGH-MALT1, and one of the few reported cases of gastric MALT lymphoma with this translocation. As this translocation is seen in only a few gastrointestinal MALT lymphomas, it is not useful as a diagnostic marker for routine clinical services. Although these findings suggest that t(14;18)/IGH-MALT1 is a rare molecular event in gastrointestinal MALT lymphomas and DLBCLs, further studies to elucidate the role of this genetic alteration in these diseases are indicated.

Abstract 3609: Generation and characterization of a novel monoclonal antibody recognizing both the blood and tissue form of human PCBP-1

Background: Poly(rC)-binding protein-1 (PCBP-1) is a nucleic-acid-binding protein that localizes in nucleus and/or cytoplasm of cells. Shuttling between nucleus and cytoplasm has been related to its function in regulation of RNA transcription, translation and also implicated its involvement in cancer metastasis, progression and chemoresistance. In the present study, we investigated the levels and expression of PCBP-1 in breast carcinoma and its potential use as a biomarker in breast carcinoma differential diagnosis. Methods/Results: We generated a novel monoclonal antibody (mAb), AB-PCBP-1 using hybridoma technology and native protein in cell culture medium as immunogen. This mAb is of IgG1 (kappa) type. It specifically recognized both native and denatured human PCBP-1 protein and displayed high affinity as assessed by ELISA, immunohistochemistry assay, western blot and flow cytometry applications. Using this mAb in competitive ELISA, we showed for the first time that soluble PCBP-1 level is significantly increased in the plasma of metastatic breast cancer patients’ plasma. PCBP-1 is also expressed in metastatic breast carcinoma tissue by immunohistochemistry. Seventy percent of normal breast ducts and lobules expressed strong nuclear staining whereas cytoplasmic staining was less specific and found in most cancer tissues. We examined 90 cases of breast carcinoma tissues classified as either ductal and lobular carcinoma. To evaluate the immunoreactivity of PCBP-1, the staining intensity and intracellular distribution were compared and scored as 0, 1+, 2+ and 3+ based on intensity. Seventy nine % (60 out of 76) of ductal carcinomas showed strong cytoplasmic staining (2+ and 3+) and 45% also exhibited strong nuclear localization for PCBP-1. Lobular carcinomas (n=14), on the other hand, showed an exclusively nuclear staining pattern.Conclusion: AB-PCBP-1 mAb showed high performance in blood and tissue assays. PCBP-1 levels were significantly increased in blood and demonstrated a distinct pattern of expression related to histological tumor types, suggesting that PCBP-1 may be involved in a regulatory mechanism that differs in various subtypes of breast carcinoma. The results suggest the potential clinical use of PCBP-1 as a therapeutic target and/or a biomarker in blood and tissue for the diagnosis and prognosis of breast carcinoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3609. doi:1538-7445.AM2012-3609

Clear Cell Tumors of Soft Tissue

Clear cell lesions of soft tissue include varying morphologic patterns and a range of clinical behaviors and prognoses. Benign lesions include perivascular epithelioid cell tumors, clear cell fibrous papule, and distinctive dermal clear cell mesenchymal tumor; malignant tumors include clear cell sarcoma, liposarcoma, and rare malignant perivascular epithelioid cell tumors. Clear cell variants of other benign and malignant soft tissue tumors include fibrous histiocytoma, atypical fibroxanthoma, myoepithelioma, leiomyoma and leiomyosarcoma, and rhabdomyosarcoma. Metastatic clear cell tumors, including renal cell carcinoma and adrenal cortical carcinoma, should be considered in the differential diagnosis and excluded through clinical history, imaging studies, and immunohistochemical stains.

Activation-induced cytidine deaminase expression in diffuse large B-cell lymphoma with a paracortical growth pattern: a lymphoma of possible interfollicular large B-cell origin

CONTEXT

Activation-induced cytidine deaminase, necessary for immunoglobulin somatic hypermutation and class switch recombination, is usually expressed within the follicular dendritic network but is also expressed in a population of interfollicular large B cells outside the germinal center.

OBJECTIVE

To report 7 cases of diffuse large B-cell lymphoma with a distinct paracortical distribution. Expression of activation-induced cytidine deaminase, previously described in interfollicular large B cells, was evaluated.

DESIGN

A panel of immunohistochemical markers, including double staining for activation-induced cytidine deaminase and CD20, was used to illustrate the cases. Molecular studies were performed by polymerase chain reaction in the paraffin-embedded tissue for t(14;18) chromosomal translocation and immunoglobulin heavy chain and T-cell receptor rearrangements.

RESULTS

Patients included 3 males and 4 females ranging in age from 11 to 59 years (mean, 39 years). All specimens were lymph nodes (4 from the groin, 2 from the neck, and 1 from the axilla). Malignant lymphocytes were positive for CD20 and negative for CD5 and CD10. Staining for CD30, CD43, and BCL-2 was variable. The malignant cells showed at least focal staining with activation-induced cytidine deaminase. All cases were found to be monoclonal by immunoglobulin heavy-chain gene rearrangement or showed light-chain restriction. None of the tested cases showed t(14;18).

CONCLUSIONS

Diffuse large B-cell lymphoma with a paracortical distribution is unusual and may be a distinct morphologic variant. More study is necessary to determine the stage of B-cell development and the cell of origin of these tumors. However, activation-induced cytidine deaminase expression suggests they may arise from a putative interfollicular large B cell.

Sporadic cutaneous angiosarcomas generally lack hypoxia-inducible factor 1alpha: a histologic and immunohistochemical study of 45 cases

Cutaneous angiosarcoma (AS) is a rare malignant neoplasm of dermis composed of infiltrating cells of endothelial phenotype with overall poor prognosis. Although autocrine stimulation by vascular endothelial growth factor secretion may play a role in the pathogenesis of angiosarcoma, its mechanism has not been fully established. Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that mediates cellular and systemic homeostatic responses to hypoxia.. The stability of HIF can regulate key proteins in angiogenesis and the alpha-subunit has been found in epithelial tumors, only 1 case of human retroperitoneal angiosarcoma, and rare vascular proliferations and tumors in knockout mice. We wanted to observe the utility of HIF-1alpha as a marker or explanatory factor in AS. Cases coded as "angiosarcoma" of dermis were culled and re-reviewed for inclusion as AS, based on patient folder, slides, and obtained immunohistochemistry including CD31 and smooth muscle actin (SMA). Hypoxia-inducible factor-1alpha was performed on a subset of cases, with additional available material. Forty-five cases met the criteria for AS; there were 17% females and 83% males, with a mean age at presentation of 67 years (range, 27-88 years). Tumors presented most commonly in the skin of the scalp followed by the left lower leg, face, nose, lower arm, neck, thigh, eyelid, ear, and temple. Associated basal cell carcinoma was noted in 1 patient; no others had other neoplasms or unrelated surgeries. There was no history of other primary, lymphedema, radiation, breast-associated, or thorotrast-induced angiosarcoma. The tumors ranged in size from 0.4 up to 9.5 cm, with a mean size of 2.4 cm. Histopathologically, most tumors were vasoformative, with either solid architecture (n = 35) or papillary endothelial hyperplasia-like foci (n = 7). All cases demonstrated infiltrative growth pattern, cytologic atypia, and mitotic activity, including atypical forms. Surface ulceration was present in 44% and solar elastosis in the most evaluable cases. Epithelioid morphology was present in 29% (n = 13) cases. Mild to moderate lymphocytic inflammatory response was noted in 62% (n = 28) cases. CD31 highlighted malignant endothelial cells. SMA (for pericytes) was generally absent. Hypoxia-inducible factor 1alpha was focally positive in cytoplasm of 3 of 18 (17%) cases studied. Treatment and follow-up data were only available on 4 cases: 2 died of disease within 4 years, 2 others had known recurrence within 2 years. Cutaneous angiosarcoma is largely found on the scalp of older individuals. Requirement for diagnosis includes extravascular proliferation of atypical endothelial cells with mitotic activity in vasoformative, solid, and papillary patterns. Absence of SMA can prove extravascular extension of tumor, outside their normal vessel confines. Cutaneous angiosarcoma generally lacks HIF-1alpha expression. Accordingly, the hypoxic response pathway is not thought to be a documentable common mechanism of angiogenesis in this entity.

Failure to detect active virus replication in mast cells at various tissue sites of HIV patients by immunohistochemistry

A recent report postulated that the mast cell population is a significant reservoir for persistent HIV infection. Our study attempted to validate this hypothesis by quantitatively comparing the distribution of mast cells and cells expressing the HIV protein p24 in HIV infected patients. Consecutive sections of paraffin-embedded human tissues from various tissue sites were subjected to immunohistochemistry with monoclonal antibodies to mast cell tryptase, viral protein p24, and other molecules. The sub-cellular distribution of these molecules was examined, to determine whether immunoreactivities to these molecules would be co-localized within the same cells. Our study revealed that, in two immediate adjacent sections immunostained for mast cell tryptase and p24, respectively, all or nearly all tryptase and p24 expressing cells were distributed at different areas. In the single section double immunostained for mast cell tryptase and p24, 5 (1.1%) of 460 large p24 expressing cell clusters encountered showed a single or few mast cells within or adjacent to p24 expressing cell clusters, but no distinct co-localization of these two proteins was observed. Similarly, no distinct co-localization was observed in any of over 500 isolated individual mast cells and p24 expressing cells. In contrast, macrophages were consistently intermixed with or adjacent to p24 expressing cells, and p24 immunostaining were seen in the cytoplasm of a subset of macrophages. These findings suggest that tissue mast cells do not show evidence for active virus replication by the techniques employed.

Acral myxoinflammatory fibroblastic sarcoma: case series and immunohistochemical analysis

BACKGROUND

Acral myxoinflammatory fibroblastic sarcoma (AMFS) is a rare, low-grade neoplasm most often occurring on the extremities of adults. It consists of mixed inflammatory infiltrates with nodules of epithelioid, spindled and bizarre-appearing cells within a fibrosclerotic-to-myxoid stroma. AMFS frequently recurs, but only rarely metastasizes.

MATERIALS AND METHODS

A retrospective analysis of all cases of AMFS seen in the past 4 years from the Stanford University Laboratory of Surgical Pathology and collaborating institutions was performed. We sought to better characterize the clinicopathologic characteristics of this rare tumor. Immunohistochemical stains, including CD34, epithelial membrane antigen (EMA), epidermal growth factor receptor (EGFR), CD117, CD163, Ki67 and p53, were also performed.

RESULTS

Eighteen cases were analyzed, and clinical information was available on 13 of them. The mean age at diagnosis was 48 years old, 10/13 (77%) occurred on the distal extremities and diameter of the lesions ranged from 1.0 to 10.0 cm. Treatment included wide local or radical excision and local recurrences were not reported. Many of the lesions were multinodular. Histologic characteristics included the presence of fibrosclerotic and myxoid stroma, sheets of spindled to round epithelioid cells, Reed-Sternberg or virocyte-like cells, lipoblast-like cells and rare mitotic figures. In most cases, CD34, EGFR and CD163 were diffusely positive. EMA and CD117 were weakly positive in some cases. Ki67 labeled < 10% of cells, and staining with P53 was variable.

CONCLUSIONS

Because AMFS may be mistaken for lymphoma, infection or tumors with higher metastatic potential, correct diagnosis is important to avoid unnecessary procedures and allow for proper clinical management. EGFR positivity suggests possible therapeutic use in aggressive cases.

Angiolymphoid hyperplasia with eosinophilia developing in a patient with history of peripheral T-cell lymphoma: evidence for multicentric T-cell lymphoproliferative process

BACKGROUND

Angiolymphoid hyperplasia with eosinophilia (ALHE) is a vasocentric process characterized by infiltrates of lymphocytes and eosinophils, usually affecting the muscular arteries of the head and neck. Currently it is unclear whether it is a reactive or neoplastic process.

REPORT

We present a 61-year-old African American male with a twenty year history of superficial skin patches involving the head and neck region. An excisional biopsy of a right submental lymph node revealed an atypical T-cell lymphocytic process, diagnosed as peripheral T-cell lymphoma after immunophenotyping and molecular studies. Three months later the patient underwent a biopsy of a left temporal nodule that was diagnosed as ALHE. Subsequently, at two year follow-up, the patient was diagnosed with Mycosis Fungoides. Polymerase chain reaction for T cell receptor gamma showed the same T-cell receptor gene rearrangement in both the temporal mass and the right submental lymph node.

CONCLUSION

ALHE with molecular evidence of monoclonality is extremely unusual, as is the association with nodal peripheral T-cell nodal lymphoma. The findings of this case support our hypothesis that ALHE might be an early form of T-cell lymphoma.

The gene trap approach in embryonic stem cells: the potential for genetic screens in mice

The gene trap approach in embryonic stem cells was developed as a means to screen for genes expressed during early postimplantation development in the mouse. We have validated the approach by showing that lacZ from the integrated vector is activated by splicing to endogenous exons and expressed in embryos in patterns that mimic those of the endogenous genes. These insertions can produce developmental defects in homozygous mice. The results indicate that a large screen of gene trap cell lines on the basis of embryonic lacZ expression is feasible and should provide a new source of genes, mouse mutants and mouse strains that express lacZ in particular domains and lineages. The gene trap approach could be extended to a smaller screen for genes based on mutant phenotypes.

Distinction of Benign Sebaceous Proliferations From Sebaceous Carcinomas by Immunohistochemistry

Sebaceous lesions, including sebaceous hyperplasia, sebaceomas, and sebaceous adenomas and carcinomas, are histologically distinctive adnexal proliferations with a spectrum of biological behavior ranging from benign to frankly malignant. The histologic distinction between sebaceous adenomas and carcinomas may be challenging, especially in cases showing atypical features and in small or partial biopsies. We studied multiple oncogenic and therapeutic related proteins by immunohistochemistry to identify differences in expression between benign and malignant sebaceous proliferations. A total of 27 cases, including 9 sebaceous adenomas, 4 sebaceomas, 8 sebaceous carcinomas, and 6 cases of sebaceous hyperplasia, were examined by immunohistochemistry, with antibodies directed against Ki-67 (MIB-1), bcl-2, p53, p21WAF1, p27Kip1, c-erbB-2 (Her-2/neu), CD117 (c-kit), cyclin D1, MDM2, CD99, MLH-1, and MSH-2. We found that sebaceous adenomas and sebaceomas stained like sebaceous hyperplasia did, whereas carcinomas had statistically significantly increased levels of p53 (50% versus 11%, respectively) and Ki-67 (30% versus 10%). The carcinomas also had significantly reduced levels of bcl-2 (7% versus 56%, respectively) and p21 (16% versus 34%) compared to the adenomas. Thus, a combination of several of these markers may be diagnostically useful in challenging cases. In addition, we found little or no Her-2/neu and CD117 staining, indicating that immunotherapy with Herceptin or Gleevac would likely not be useful for sebaceous carcinomas. Moreover, these results show that sebaceous adenomas and carcinomas are distinct neoplasms and provide no support for the theory that all sebaceous adenomas are truly malignant.

Rare primary CNS anaplastic large cell lymphoma in an immunocompetent adult: a clinical-pathologic case report and review case of the literature

OBJECTIVE AND IMPORTANCE

Isolated anaplastic large cell lymphoma (ALCL) presenting in the primary central nervous system is distinctly uncommon. The authors describe a case that clinically and radiographically simulated a primary glial neoplasm.

CLINICAL PRESENTATION

A 39-year-old immunocompetent male presented with seizures and a rapidly enlarging right occipital/parietal lesion. Magnetic resonance images demonstrated a right occipitoparietal lesion, hypodense on T1WI, with patchy contrast enhancement with gadolinium and significant white matter edema pattern on T2WI along with mass effect and midline shift.

INTERVENTION

The patient underwent a frameless stereotactic assisted needle biopsy. There appeared to be a clear demarcation between white matter and tumor with no obvious necrosis. Biopsy showed a proliferation of single cells and poorly cohesive groups of cells with large, pleomorphic nuclei, many containing prominent nucleoli, and a moderate amount of cytoplasm. Immunohistochemical staining revealed CD-30 and ALK-positivity typical of ALCL, a rare form of T-cell lymphoma. An extensive workup revealed neither systemic disease nor evidence of immunocompromise.

CONCLUSION

Reported in less than 20 patients, primary ALCL in an immunocompetent patient is rarely found intracranially; however, its ability to mimic glial neoplasms as well as other pathologies underlines its importance.

The effects of gp100 and tyrosinase peptide vaccinations on nevi in melanoma patients

BACKGROUND

A new approach to prevent disease recurrence in high-risk melanoma patients involves immunization with gp100 and tyrosinase peptides. This is the first study to examine the effects of such treatments on nevi.

DESIGN

We studied biopsies of 'clinically atypical' nevi from 10 patients before and after peptide vaccination. All had a cutaneous melanoma measuring at least 1.5 mm in depth, satellite metastases, or at least one positive lymph node. We performed immunohistochemical stains for CD3, CD4, CD8, MHC-I, MHC-II, CD1a, HMB-45, MART-1, tyrosinase, bcl-2, p53, and Ki-67 (mib-1).

RESULTS

Immunohistochemistry showed no differences in staining due to vaccination in either the immunologic or melanocytic markers. However, there was a significant increase in both p53 and bcl-2 staining, and a trend toward decreased Ki-67 staining, in the nevi post-treatment.

DISCUSSION

The primary goal of peptide vaccinations with gp100 and tyrosinase is to activate melanoma-specific T cells in order to prevent melanoma recurrence. Nevi were studied in order to assess the effects on benign melanocytes. No significant changes in lymphocytes, langerhans cells, expression of MHC antigens, or melanocytic markers were found. The increase in p53 and bcl-2 raises the possibility that vaccination with melanocytic antigens stimulates a response in benign melanocytes.