The spectrum of cutaneous lymphomas in patients less than 20 years of age

Paediatric cutaneous lymphomas including rare subtypes: A 40-year experience at a tertiary referral centre

BACKGROUND

Primary cutaneous lymphomas are neoplasms of the immune system with a distinct tropism for the skin and an absence of extracutaneous manifestations at the time of diagnosis. Studies focusing on cutaneous lymphomas in children and adolescents remain scarce and often do not encompass the rare subtypes.

OBJECTIVES

To address this knowledge gap by describing the clinical, histological and molecular characteristics of a large group of paediatric patients affected by primary cutaneous lymphoma. We also provided the Paediatric Primary Cutaneous Lymphoma Atlas that illustrates the clinicopathological spectrum of observed presentations, in the hope of supporting other physicians in the diagnostic process.

METHODS

Retrospective chart review of paediatric patients diagnosed with primary cutaneous lymphomas between 1980 and 2022 at the Paediatric Dermatology Unit of Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan.

RESULTS

A total of 101 patients (58 males, 43 females) met the inclusion criteria. The most common subtypes were lymphomatoid papulosis (n = 48) and mycosis fungoides (n = 31). These were followed by primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorders (n = 7), primary cutaneous anaplastic large-cell lymphomas (n = 5), primary cutaneous marginal zone B-cell lymphomas (n = 3), primary cutaneous follicle centre lymphomas (n = 2), subcutaneous panniculitis-like T-cell lymphomas (n = 2), primary cutaneous peripheral T-cell lymphoma not otherwise specified (n = 1), primary cutaneous precursor B-lymphoblastic lymphoma (n = 1) and Sézary syndrome (n = 1). Clinical follow-up data covering a median of 70.8 months (range 1-324) were available for 74 patients, of whom three died due to cutaneous lymphoma.

CONCLUSIONS

Our findings shed light on the peculiar aspects and long-term outcomes of paediatric cutaneous lymphomas, particularly emphasizing their distinctive features in comparison to their adult counterparts and exploring the less common subtypes. Further larger-scale studies are warranted to better characterize these entities and to achieve a more rapid and accurate diagnosis.

An adolescent with primary cutaneous follicle center lymphoma: a case report and literature review

Primary cutaneous follicle center lymphoma (PCFCL) differs from follicular lymphoma in biological behavior and molecular profile and is treated as a distinct entity, according to the 5th edition of the World Health Organization classification of hematolymphoid tumors. It is an uncommon cutaneous B-cell lymphoma that is considerably rare in children and adolescents. To date, only 13 cases of individuals younger than 20 years of age have been reported in the literature. The lack of relevant clinical epidemiological data in this population has hampered the investigation of its clinical and diagnostic aspects. Here we report the case of a 17-year-old male with PCFCL, who may be the first PCFCL patient under 20 years of age reported in China. He was admitted to the hospital with a solitary nodule on his face. After complete surgical excision, the patient's facial mass was histologically identified as PCFCL. The patient's prognosis was favorable, with no recurrence at 17 months of follow-up after the surgical resection. We present a case of an adolescent PCFCL patient and systematically review the literature with a view to increase the awareness of the disease and inform the diagnosis and treatment of this age group.

Skin Involvement by Hematological Neoplasms with Blastic Morphology: Lymphoblastic Lymphoma, Blastoid Variant of Mantle Cell Lymphoma and Differential Diagnoses

Hematological neoplasms sharing a blastic morphology may involve the skin. The skin may be either the primary site of occurrence of hematological malignancies with blastic features or cutaneous lesions are the first manifestation of an underlying systemic malignancy. The assessment of skin biopsies of hematological neoplasms with blastic features poses diagnostic problems and requires expert hematopathologists considering a wide range of differential diagnoses. The precise diagnosis of diseases sharing blastic features but with different outcomes and requiring distinct therapies is essential for patient management. The present paper mainly focuses on cutaneous involvement of the blastoid variant of mantle cell lymphoma and lymphoblastic lymphoma of B-cell or T-cell origin. The relevant literature has been reviewed and the clinical aspects, pathological features, prognosis, and therapy of both blastoid mantle cell lymphoma and lymphoblastic lymphoma involving the skin are discussed. A focus on other hematological entities with blastic features, which may involve the skin, to be taken into consideration in differential diagnosis is also given.

Diagnosis and management of cutaneous lymphomas and lymphoid proliferations in children, adolescents and young adults (CAYA)

Cutaneous lymphomas and lymphoid proliferations (LPD) in children, adolescents, and young adults (CAYA) are a heterogeneous group of lymphoid neoplasms that present formidable diagnostic challenges to clinicians and pathologists alike. Although rare overall, cutaneous lymphomas/LPD occur in real-world settings and awareness of the differential diagnosis, potential complications, and various therapeutic approaches will help ensure the optimal diagnostic work-up and clinical management. Lymphomas/LPD involving the skin can occur as primary cutaneous disease in a patient that characteristically has lymphoma/LPD confined to the skin, or as secondary involvement in patients with systemic disease. This review will comprehensively summarize both primary cutaneous lymphomas/LPD that occur in the CAYA population as well as those CAYA systemic lymphomas/LPD with propensity for secondary cutaneous involvement. Focus on the most common primary entities occurring in CAYA will include lymphomatoid papulosis, primary cutaneous anaplastic large cell lymphoma, mycosis fungoides, subcutaneous panniculitis-like T-cell lymphoma, and hydroa vacciniforme lymphoproliferative disorder.

Primary Cutaneous Follicle Center Lymphoma Presenting as a Solitary Nodule on the Forearm of an Adolescent Girl: A Case Report and Literature Review

Primary cutaneous B-cell lymphomas (PCBCLs) are very rare to be seen in pediatric and adolescent age group, especially primary cutaneous follicle center lymphoma (PCFCL) which is considered the least occurring main subtype. Here, we describe a 16-year-old girl who developed a slowly growing solitary firm smooth surfaced erythematous nodule over her forearm. Histopathological examination showed a dense dermal nodular, periadnexal and perivascular lymphoid infiltrate extending deep to the subcutis. Immunohistochemical staining showed a B-cell population with positivity for CD20, variable staining for BCL6 and CD10 and uniquely staining for BCL2. Although a primary cutaneous marginal zone lymphoma (PCMZL) was considered but the presences of interfollicular BCL6 and CD10 positivity established the diagnosis of PCFCL. To our knowledge, only 12 cases of pediatric and adolescent PCFCL have been described in the literature.

Mycosis fungoides in pediatric population: comprehensive review on epidemiology, clinical presentation, and management

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma. However, it is rare in pediatric population. Most of the cases of pediatric MF present with hypopigmented patches and/or various other forms, which may often mimic common childhood dermatoses, thereby causing a delay in the diagnosis. There are no established treatment guidelines for pediatric MF. As the progression of childhood MF is extremely rare and it has an indolent course, it is usually diagnosed at an early stage (IA, IB, IIA), and hence phototherapy with a response rate of >80% is a well-established effective treatment in children. However, as recurrences are frequently seen on stopping the therapies, a maintenance regimen and long-term follow-up is equally important. This article reviews the epidemiological factors, clinical presentations, diagnosis, and various treatment modalities used in pediatric MF. We analyzed and compared the data of almost 616 childhood MF cases from various studies undertaken from 1988 to 2021.

Pediatric Mycosis Fungoides: Retrospective Analysis of a Series With CD8 + Profile and Female Predominance

BACKGROUND

Mycosis fungoides (MF) in children is a rare disease and there are limited data regarding the behavior of the disease in this age group. We aimed to collect additional data to better understand the clinicopathologic features of MF in children.

MATERIALS AND METHODS

This study was a retrospective analysis of pediatric MF patients (diagnosed at age 0 to 18 y).

RESULTS

Thirteen pediatric patients with MF were identified. Female predominance was observed with a ratio of 1.6:1. Median values for age of onset of skin lesions and age at the time of histologic diagnosis were 5 and 12 years, respectively. All patients had early stage (stage IA to IIA) of MF at the time of diagnosis. Hypopigmented MF comprised 77% of all study patients, followed by classic MF (15%) and pagetoid reticulosis (8%). The lower extremity (especially proximal leg) followed by trunk and upper extremity were most commonly affected sites. Seven of 9 patients who had available immunohistochemistry data showed CD8 + predominance. Five of 8 patients whose follow-up data was available, achieved complete response with narrowband ultraviolet B treatment, while 2 and 1 had near complete response and partial response, respectively.

CONCLUSIONS

Our study demonstrated female sex and CD8 + profile predominance. Hypopigmented MF constituted the majority of cases. We observed good responses with narrowband ultraviolet B treatment.

Non-Hodgkin Lymphoma Imaging Spectrum in Children, Adolescents, and Young Adults

In children, adolescents, and young adults (CAYA), non-Hodgkin lymphoma (NHL) is characterized by various age-related dissimilarities in tumor aggressiveness, prevailing pathologic subtypes, and imaging features, as well as potentially different treatment outcomes. Understanding the imaging spectrum of NHL in CAYA with particular attention to children and adolescents is critical for radiologists to support the clinical decision making by the treating physicians and other health care practitioners. The authors discuss the currently performed imaging modalities including radiography, US, CT, MRI, and PET in the diagnosis, staging, and assessment of the treatment response. Familiarity with diagnostic imaging challenges during image acquisition, processing, and interpretation is required when managing patients with NHL. The authors describe potentially problematic and life-threatening scenarios that require prompt management. Moreover, the authors address the unprecedented urge to understand the imaging patterns of possible treatment-related complications of the therapeutic agents used in NHL clinical trials and in practice. Online supplemental material is available for this article. ^©RSNA, 2022.

Two Histologic Patterns of Lymphomatoid Papulosis Occurring in a Child: A Matter of Timing?

There are several histologic patterns seen in lymphomatoid papulosis, with the possibility of different subtypes occurring in the same patient. We report a case of lymphomatoid papulosis presenting with 2 histologic subtypes (types A and B) occurring concomitantly in a 10-year-old child, and postulate that the different subtypes occur dependent on the age of the lesion biopsied. Incidentally, one of the biopsies also shows a rarely seen pattern of pseudoepitheliomatous hyperplasia in a pediatric lymphomatoid papulosis patient.

Pediatric Cutaneous Hematologic Disorders: Cutaneous Lymphoma and Leukemia Cutis: Experience of a Tertiary-Care Pediatric Institution and Review of the Literature

BACKGROUND

Cutaneous hematologic malignancies are rare in children, and the literature about them is still sparse.

OBJECTIVE

The purpose of our study was to report our experience with pediatric cases of cutaneous hematologic disorders and describe their clinical and histological features.

METHODS

Data were retrospectively collected from the histopathologic database of the CHU Sainte-Justine, University of Montreal, Montreal, Canada. All patients up to 18 years of age with a diagnosis of a primary cutaneous lymphoma (including lymphomatoid papulosis), secondary cutaneous lymphoma or cutaneous manifestations of leukemia, followed from 1980 to 2019 at our center were reviewed.

RESULTS

Thirty-six patients were included. Age at presentation ranged from birth to 18 years of age (mean 7.83 ± 5.16; median 7.0). Ten different hematologic disorders were identified according to the WHO-EORTC classifications: lymphomatoid papulosis (10 cases), mycosis fungoides (6 cases), anaplastic large cell lymphoma (4 cases), pre-B acute lymphoid leukemia (5 cases), primary cutaneous marginal zone B-cell lymphoma (4 cases), primary cutaneous CD4⁺medium T-cell lymphoproliferative disorder (1 case), extranodal NK/T-cell lymphoma (1 case), hydroa vacciniforme-like lymphoproliferative disorder (1 case), B-cell lymphoblastic lymphoma (1 case) and acute myeloid leukemia (3 cases).

CONCLUSION

The most common subtype of cutaneous hematologic disease in our single institution study was lymphomatoid papulosis (type A and type C), followed by mycosis fungoides. Recognition of this large clinical and histological spectrum by dermatologists is important because diagnosis is often established by biopsy of skin lesions, even in secondary cutaneous cases. Moreover, the clinicopathological correlation is of utmost importance for the final diagnosis of those pathologies.

Pediatric mycosis fungoides - characteristics, management, and outcomes with particular focus on the folliculotropic variant

BACKGROUND

The literature on pediatric mycosis fungoides (MF) and especially its folliculotropic variant (FMF) is sparse.

OBJECTIVES

To describe the clinical manifestations, treatments, outcomes and long-term course of pediatric MF, including FMF.

METHODS

A retrospective analysis was conducted of all consecutive MF patients diagnosed at ≤18 years attending two medical centers in 1995-2015.

RESULTS

The cohort included 71 patients, all but 2 of whom had early-stage disease: hypopigmented (55%) folliculotropic (42%) and classical MF (39%), alone or in combination. The head and neck area was involved in 43% of patients with early-stage FMF compared to 12% of the non-FMF group (p=0.004). There was no difference in the involvement of other body areas between the groups. Pruritus, although mild, was more often recorded among patients with early-stage FMF compared to non-FMF (58% vs. 29%, respectively, P=0.02). Complete response (CR) was achieved in 60 of the 69 patients with early-stage MF (87%) after an average of 1.8 treatment modalities. NBUVB was the most administered treatment to non-FMF patients with CR rates of 63% versus 29% of FMF patients (P=0.04). Systemic/bath PUVA, or UVA+NBUVB were the most administered treatments to FMF patients with CR rates of 60% versus 81% for non-FMF patients (P=0.17). During a mean follow-up of 9.2 years (range 1-24), stage progression was observed in 4 (6%) of the patients with early-stage disease, 2 of whom (all FMF) to advanced stage.

CONCLUSIONS

Pediatric MF presents as an early-stage disease with over-representation of hypopigmented and FMF variants. NBUVB and UVA-based therapies yield good response rates in non-FMF and FMF patients, respectively. Disease course is indolent, and even on relatively long follow-up, it has a very low progression rate from early to advanced-stage disease, occurring in patients with FMF. We propose a treatment algorithm for pediatric MF.

Surviving With Mycosis Fungoides for Twenty Years: An Autobiographical Case Report

Mycosis fungoides (MF) is a low-grade chronic lymphoid proliferative disorder of T-lymphocytes arising out of the skin, having an indolent course caused by abnormal proliferation of CD4+ T-cells. Here we present a case of a 37-year-old male who was diagnosed with mycosis fungoides in 2001 and treated with Total Skin Electron Beam Therapy (TSEBT). The purpose of this autobiographical case report is to give an insight into the eventful journey of the patient living with the disease for the last 20 years. His journey will serve the purpose of both patients and physicians and will add to the literature on the subject.

Primary cutaneous lymphomas in children: A prospective study from the Spanish Academy of Dermatology and Venereology (AEDV) Primary Cutaneous Lymphoma Registry

BACKGROUND/OBJECTIVES

Primary cutaneous lymphomas are rare in pediatric patients. The clinical and histopathological manifestations may differ from those in adults. Due to their low frequency and the insidious clinical picture, the diagnosis is usually delayed. The Spanish Primary Cutaneous Lymphoma Registry was initiated in 2016 as a multicenter registry that would allow better insight into the epidemiological, clinical, histopathological, and treatment response characteristics of patients with primary cutaneous lymphomas.

METHODS

We conducted a prospective observational cohort study of primary cutaneous lymphomas in pediatric patients participating in the Spanish Academy of Dermatology and Venereology (AEDV) Primary Cutaneous Lymphoma Registry.

RESULTS

At the time of the analysis, 10 patients under 18 years of age out of 799 all-age cases (1.25%) had been included in the registry (7 males, 3 females). The mean age at diagnosis was 9.7 years (SD: 4.8). Seven (70%) had mycosis fungoides, 2 of them had the folliculotropic variant; and 3 (30%) had primary cutaneous marginal zone B-cell lymphoma.

CONCLUSIONS

Primary cutaneous lymphomas are extremely rare in pediatric patients and usually have a good prognosis. Therefore, a high level of suspicion is necessary for the diagnosis. We suggest management by experienced physicians and follow-up into adulthood.

Association of marital status with stage and survival in patients with mycosis fungoides: A population-based study

BACKGROUND

Previous studies have shown that marital status was associated with stages and survival in patients with melanoma or Merkel cell carcinoma. To date, the impacts of marital status on stage and survival in patients with mycosis fungoides (MF) have not been determined yet.

METHODS

A total of 3375 eligible cases diagnosed from 2004 to 2015 were included from the Surveillance, Epidemiology, and End Results (SEER) database. Association of marital status with stage and survival in patients with MF was analyzed.

RESULTS

Married patients were more likely to be diagnosed at T1 stage (p = 0.041). And married patients were less likely to present with lymph node involvement (p = 0.007). More favorable overall survival (p < 0.001) and cancer-specific survival (p < 0.001) were demonstrated in married patients as compared with divorced patients or widowed patients. A clinically feasible prognostic model including marital status, age, sex, race, and stage at presentation was constructed.

CONCLUSION

Married marital status was associated with earlier stage at diagnosis and longer survival compared with divorced or widowed marital status in patients with MF.

Primary cutaneous T-cell lymphomas in childhood and adolescence

Primary cutaneous lymphomas are extranodal non-Hodgkin lymphomas of T- or B- cell origin, that predominantly affect older patients but have been reported in all age groups and as early as in the first years of life. Diagnosis of cutaneous lymphomas is challenging and requires high clinical suspicion and close collaboration between dermatologists, pediatric oncologists and pathologists. Skin involvement of non-Hodgkin lymphomas in children or adolescents can either be primary cutaneous or secondary due to an underlying nodal lymphoma. The most common primary cutaneous lymphomas encountered in children are of T-cell origin, with mycosis fungoides being the most prevalent cutaneous T-cell lymphoma, followed by CD30⁺ lymphoproliferative disorders. While cutaneous lymphomas share clinicopathologic characteristics between juvenile and adult forms, there are important differences in terms of clinical presentation, diagnosis and treatment. The hypopigmented variant of mycosis fungoides seems to be overrepresented in the pediatric age group. Prognosis and treatment of mycosis fungoides are stage dependent. The majority of children present with early-stage disease and respond well to topical corticosteroids and phototherapy.

Primary Cutaneous B-Cell Lymphomas in Children and Adolescents: A SEER Population-Based Study

BACKGROUND

Although primary cutaneous B-cell lymphomas (PCBCL) comprise 25% of all cutaneous lymphomas, their incidence in the pediatric population is unknown, and the information on pediatric PCBCL has mostly been gathered from individual case reports or series from single centers.

PATIENTS AND METHODS

This was a population-based, retrospective cohort study of patients in 18 cancer registries in the United States diagnosed between 2000 to 2016 through the Surveillance, Epidemiology, and End Results (SEER) program. Age-adjusted incidence rates were calculated for PCBCL in pediatric (<20 years) and adult (≥20 years) populations. Demographic, clinical, and pathological characteristics of PCBCL were compared between the two groups.

RESULTS

A total of 48 pediatric and 5128 adult PCBCL cases were included. Median age at diagnosis was 16.5 years and 65 years in the two groups, respectively. The major histologic subtypes of pediatric cases were marginal zone lymphoma (77.1%), followed by diffuse large B-cell lymphoma (12.5%) and follicle center lymphoma (10.4%), which were equally distributed in adults. The age-adjusted pediatric PCBCL incidence rate (per 1,000,000 person-years) was 0.12 (95% CI 0.09-0.16). The incidence in the adult population was approximately 40-fold higher than the one observed in the pediatric group (IRR 41.4, 95% CI 31.2-56.2). All 48 pediatric cases were alive during a median follow-up time of 48 months.

CONCLUSIONS

Pediatric PCBCL is a very rare disease affecting mostly adolescents of both sexes. The major histologic subtype is marginal zone lymphoma, and the prognosis is favorable.

Primär kutane T‐Zell‐Lymphome im Kindes‐ und Jugendalter

Primär kutane Lymphome sind extranodale T- oder B-Zell-Non-Hodgkin-Lymphome, die vorwiegend ältere Patienten betreffen, aber in allen Altersgruppen einschließlich der ersten Lebensjahre auftreten können. Die Diagnose kutaner Lymphome ist eine Herausforderung und erfordert einen hohen klinischen Verdacht sowie enge Zusammenarbeit zwischen Dermatologen, pädiatrischen Onkologen und Pathologen. Generell müssen primär kutane Lymphome von sekundär kutanen Lymphomen, welche meist von nodalen oder extranodalen Lymphomen ausgehen, unterschieden werden. Die häufigsten primär kutanen Lymphome im Kindesalter sind T-Zell Lymphome, wobei Mycosis fungoides das häufigste kutane T-Zell-Lymphom darstellt, gefolgt von CD30+ lymphoproliferativen Erkrankungen. Während klinisch-pathologische Merkmale kutaner Lymphome bei Jugendlichen und Erwachsenen ähnlich sind, gibt es wichtige Unterschiede bezüglich klinischer Präsentation, Diagnose und Behandlung. Die hypopigmentierte Variante der Mycosis fungoides scheint in der pädiatrischen Altersgruppe überrepräsentiert zu sein. Prognose und Behandlung der Mycosis fungoides sind stadienabhängig. Die Mehrheit der Kinder weist ein frühes Krankheitsstadium auf und spricht gut auf topische Kortikosteroide und Phototherapie an.

Primary cutaneous follicle center lymphoma in a 16-year-old girl

In the pediatric and adolescent age group, primary cutaneous lymphomas are rare, especially cutaneous B-cell lymphomas. According to the World Health Organization, the three main subtypes of primary cutaneous B-cell lymphomas are primary cutaneous marginal zone B-cell lymphoma (PCMZL), primary cutaneous follicle center lymphoma (PCFCL), and primary cutaneous diffuse large B-cell lymphoma, leg type. We present an extraordinary case of PCFCL arising in a 16-year-old female, only the sixth case of PCFCL to be reported in the literature in a patient less than 20 years old. Although PCMZL was considered in this case, the finding of lambda light chain restriction in the BCL-6 and CD10 positive population of lymphocytes established the diagnosis of primary cutaneous follicle center lymphoma. Not many data currently exist on the prognosis of PCFCL in young individuals, but adult PCFCL has a good prognosis with an indolent course and 5-year survival rates over 95%. Because of its uncommon manifestation in young patients, the diagnosis of PCFCL is often delayed or missed. This case is presented to raise awareness of PCFCL in the pediatric/ adolescent population and to contribute to the ongoing research of this condition.

Role of chromatin assembly factor-1/p60 and poly [ADP-ribose] polymerase 1 in mycosis fungoides

Mycosis fungoides (MF) represents the most common type of cutaneous lymphoma. In the majority of patients, the disease has a slow evolution and a protracted course; however, a subset of patients shows poor oncologic outcomes. Unfortunately, there are no reliable prognostic markers for MF, and the currently available treatments are only effective in a minority of patients. This study aimed to evaluate the expression and clinical significance of PARP-1 and CAF-1/p60 in MF. Sixty-four MF representatives of the different stages of disease were assessed by immunohistochemistry for PARP-1 and CAF-1/p60. The association of PARP-1 and CAF-1/p60 with the MF stage and outcome was assessed by using Fisher’s exact test and Kaplan-Meier survival analysis with the Log-rank test; a p value < 0.05 was considered significant. PARP-1 was overexpressed in 57.9% of MF and was significantly associated with a MF stage > II (p = 0.034) but not with the risk of death (p = 0.237). CAF-1/p60 was overexpressed in 26.8% of MF and was significantly associated with decreased overall survival (p < 0.001) but not with the MF stage (p = 1). A significant association was found between PARP-1 overexpression and CAF-1/p60 overexpression (p = 0.0025). Simultaneous overexpression of PARP-1 and CAF-1/p60 was significantly associated with decreased overall survival (p < 0.001), although less strongly than CAF-1/p60 alone (χ² = 14.916 vs 21.729, respectively). In MF, PARP-1 is overexpressed in advanced stages, while CAF-1/p60 is overexpressed in the cases with shorter overall survival, appearing as a significant prognostic marker. A role for PARP-1 inhibitors and anti-CAF-1/p60 targeted therapy may be reasonably hypothesized in MF.

How I Diagnose Primary Cutaneous Marginal Zone Lymphoma

OBJECTIVES

Primary cutaneous marginal zone lymphoma (PCMZL) is 1 of the 3 major subtypes of primary cutaneous B-cell lymphoma. The diagnosis of PCMZL may be challenging, as the differential diagnosis includes benign cutaneous lymphoproliferations as well as other primary or secondary cutaneous B-cell or T-cell lymphomas. This review describes our approach to the diagnosis of PCMZL.

METHODS

Two cases are presented that illustrate how we diagnose each of the 2 subtypes of PCMZL. The clinicopathologic features of PCMZL and the ways in which these cases can be distinguished from both benign and other neoplastic entities are emphasized.

RESULTS

A definitive diagnosis of PCMZL requires the incorporation of histologic and immunophenotypic features, molecular genetic studies in some cases, and just as importantly, clinical findings. Emerging data suggest that the heavy chain class-switched cases may be more like a clonal chronic lymphoproliferative disorder.

CONCLUSIONS

The 2 subtypes of PCMZL create different diagnostic challenges and require the use of a multiparameter approach. Although very indolent, it is important to distinguish PCMZLs from reactive proliferations, because they frequently recur and may require antineoplastic therapies. It is also critical to distinguish PCMZLs from other B- or T-cell lymphomas so that patients are properly evaluated and not overtreated.

A Systematic Approach to the Cutaneous Lymphoid Infiltrates: A Clinical, Morphologic, and Immunophenotypic Evaluation

CONTEXT.—

The evaluation of cutaneous lymphoid infiltrates, both neoplastic and inflammatory, occurs very frequently in routine dermatopathologic examination and consultation practices. The "tough" cutaneous lymphoid infiltrate is feared by many pathologists; skin biopsies are relatively small, whereas diagnostic possibilities are relatively broad. It is true that cutaneous lymphomas can be difficult to diagnose and that in many circumstances multiple biopsies are required to establish a correct diagnostic interpretation. As a reminder, one should understand that low-grade cutaneous lymphomas are indolent disorders that usually linger for decades and that therapy does not result in disease cure. It is also important to remember that in most circumstances, those patients will die from another process that is completely unrelated to a diagnosis of skin lymphoma (even in the absence of specific therapy).

OBJECTIVE.—

To use a clinicopathologic, immunophenotypic, and molecular approach in the evaluation of common lymphocytic infiltrates.

DATA SOURCES.—

An in-depth analysis of updated literature in the field of cutaneous lymphomas was done, with particular emphasis on updated terminology from the most recent World Health Organization classification of skin and hematologic tumors.

CONCLUSIONS.—

A diagnosis of cutaneous lymphoid infiltrates can be adequately approached using a systematic scheme following the proposed ABCDE system. Overall, cutaneous T- and B-cell lymphomas are rare and "reactive" infiltrates are more common. Evaluation of lymphoid proliferations should start with a good sense of knowledge of the clinical presentation of the lesions, the clinical differential considerations, and a conscientious and appropriate use of immunohistochemistry and molecular tools.

Mycosis fungoides in pediatric patients: Clinical features, diagnostic challenges, and advances in therapeutic management

Mycosis fungoides (MF) is the most common primary cutaneous lymphoma in pediatric patients. Given the indolent nature of MF, symptoms often present in childhood but may not be diagnosed as MF until adulthood. Delayed diagnosis is associated with poor long-term prognosis. Thus, increased clinician recognition and accurate diagnosis of early-stage MF in pediatric patients is critically important. In this review, we summarize the clinical features of the most common pediatric MF subtypes and highlight important differences between pediatric and adult MF. Moreover, we reviewed all pediatric MF case series published between 2008 and 2018 to analyze treatment modalities and identify emerging therapies. As treatment of pediatric MF is complex, selection of therapy varies significantly depending upon the specific clinical characteristics, disease severity, and patients' preferences.

Epidemiological, clinical, histological, and immunohistochemical study on hypopigmented epitheliotropic T-cell dyscrasia and hypopigmented mycosis fungoides

BACKGROUND

Hypopigmented dermatoses, more evident in dark-skinned people, are a frequent cause of consultation. Their etiology includes a wide range of dermatoses, from benign to malignant diseases. The clinical presentation appears very similar between them, making the correct diagnoses and management a challenge.

METHODOLOGY

Clinical records and histopathological biopsies were identified and compared in patients of the "Dr. Manuel Gea González" General Hospital throughout a 16-year period with the presumptive diagnosis of hypopigmented epitheliotropic T-cell dyscrasia (HTCD) or hypopigmented mycosis fungoides (HMF). Immunostaining analysis was performed in each specimen, the panel of antibodies used was: CD3, CD4, CD7, CD8, CD20, and CD62L.

RESULTS

Thirty cases of 81 patients found in the registries were included in this study. The main age group was formed by children younger than 15 years old. The main clinical differences between both entities were gender, presence of plaques, and neck lesions. The most significant histopathological parameters used to differentiate both diagnoses were: severity of lymphocytic infiltration, the extent of epidermotropism, folliculotropism, presence of Pautrier's microabscesses, lymphocytes with cerebriform nuclei, and dermal fibroplasia. No immunohistochemical differences were found between them.

CONCLUSION

The clinical distinction between HTCD and HMF continues to be a challenge, therefore an extensive clinicopathological correlation must be performed. AbCD7 and AbCD62L were not useful to differentiate both dermatoses. This paper suggests that HTCD and HMF should be considered as the beginning and the end of the same clinical spectrum.

Diagnosis and Management of Cutaneous B-Cell Lymphomas

Primary cutaneous B-cell lymphomas are a group of diseases with indolent and aggressive behavior. The goal of the initial workup is to evaluate for systemic involvement, provide adequate staging, and guide therapy. Histopathological studies are a critical part of the workup for classification of these lymphomas because they are similar to their nodal counterparts. There are limited data for treatment guidelines, and thus, therapy differs among institutions. Overall, localized therapies are preferred for indolent types and chemotherapy or immunotherapy for the aggressive forms.

Primary cutaneous lymphoma in Argentina: a report of a nationwide study of 416 patients

BACKGROUND

The aim of this study was to determine the relative frequency of primary cutaneous lymphoma (PCL) in Argentina according to the new World Health Organization (WHO)-European Organization for the Research and Treatment of Cancer (EORTC) classification system.

METHODS

A total of 416 patients from 21 dermatology services were included during a 5-year period (2010-2015); these patients were classified using WHO-EORTC criteria.

RESULTS

There were 231 (55.2%) males and 185 (44.8%) females; the male-to-female ratio was 1.35. The median age of the patients was 57 years (range, 0-90 years). Most patients were Caucasian (79%), and only 16% of patients were registered as Amerindian. Most patients (387/416, 93%) had cutaneous T-cell lymphoma (CTCL); 28 patients (6.7%) were diagnosed with cutaneous B-cell lymphoma (CBCL). The most frequent CTCL subtypes, in decreasing order of prevalence, were mycosis fungoides (MF), including its variants (75.7%); CD30+ primary cutaneous lymphoproliferative disorders (7.2%); and Sézary syndrome (SS) (3.1%). Cutaneous follicle center lymphoma was the most common CBCL subtype (2.9%). In the subset of patients ≤20 years of age, the most common condition was MF (57%), followed by extranodal NK-T nasal-type lymphoma (14%).

CONCLUSIONS

This study revealed relatively higher rates of MF and lower rates of CBCL in Argentinean patients that have been reported in American and European countries.

Juvenile-Onset Early-Stage Mycosis Fungoides-Associated Follicular Mucinosis: A Case Report

We report a juvenile case of mycosis fungoides with prominent follicular mucinosis (FM). The patient was a 9-year old boy who presented with a 2-month history of enlarging alopecic patch with fine scales on the scalp. Dermatologic examination revealed orange-tan slightly palpable plaques with follicular prominence on his trunk. The patient and his family were not aware of these asymptomatic truncal plaques. Histopathologic examination of both-scalp and trunk-lesions revealed folliculotropic lymphocytic infiltration with mucin. Immunohistochemical study showed that lymphocytic infiltration was CD4 dominant. Flow cytometry analyses of peripheral blood were normal. Any abnormal populations and Sézary cells were not observed on blood smear. Polymerase chain reaction testing showed monoclonality for the T-cell receptor4-[Latin Small Letter Rams Horn] gene. Our patient had the clinical and histopathological diagnosis of follicular mycosis fungoides-associated follicular mucinosis.

Primary Pediatric Cutaneous T-Cell Lymphoproliferative Disorders: 3 New Cases

Primary cutaneous lymphoproliferative disorders are a composite group of diseases with considerable differences in histopathologic, immunophenotypic, and clinical features. They are exceedingly rare in children and in the literature only few cases are reported with extremely different therapeutic approaches. Because of the rarity of cutaneous lymphomas we consider crucial to increase the knowledge of these diseases providing every single case. We present 3 pediatric cases of primary cutaneous T-cell lymphomas occurred to our center with different features and therapeutic approach.

Cutaneous Hematolymphoid and Histiocytic Proliferations in Children

This article focuses on cutaneous hematopoietic neoplasms that are more likely to be encountered in the pediatric age-group and includes both lymphoproliferative and histiocytic disorders. The cutaneous hematologic disorders in children have a different epidemiologic profile to what is seen during adulthood. Although mycosis fungoides is the most frequent form of cutaneous lymphoma in adults, it is very rare in children. Because lymphoblastic leukemias and lymphomas are more frequent in the pediatric setting, cutaneous leukemic infiltrates are relatively common in this age-group. Similarly, histiocytic disorders are more common in children, particularly Langerhans cell histiocytosis and juvenile xanthogranuloma. Notably, the histiocytic disorders have undergone significant modifications on their nomenclature in the basis of the molecular characteristics that are present in them. A summary of the most frequent cutaneous hematopoietic disorders in children will be discussed further in this review.

How to Discern Folliculotropic Mycosis Fungoides From Follicular Mucinosis Using a Pediatric Case

Folliculotropic mycosis fungoides (FMF) is a variant of mycosis fungoides (MF) with folliculotropic, atypical lymphocytes that may or may not have mucin deposition surrounding the hair follicle. Follicular mucinosis (FM) is a primary or secondary finding in FMF, lupus, or collagen vascular diseases that is only a histological process of mucin deposition surrounding the hair follicles. We present a case of a 6-year-old boy who had features of both FMF and primary follicular mucinosis (PFM). The case reveals key insights on FMF with concurrent FM in pediatric patients and how to differentiate between FMF and PFM.

Primary Cutaneous B-cell Lymphomas

B-cell lymphomas represent approximately 20% to 25% of primary cutaneous lymphomas. Within this group, most cases (>99%) are encompassed by 3 diagnostic entities: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg type. In this article, the authors present clinical, histopathologic, immunophenotypic, and molecular features of each of these entities and briefly discuss the rarer intravascular large B-cell lymphoma.

Primary Cutaneous B-Cell Lymphoblastic Lymphoma Arising from a Long-Standing Lesion in a Child and Review of the Literature

Precursor B-cell lymphoblastic lymphoma (B-LBL) is a rare entity and primary cutaneous B-LBL is an even more uncommon diagnosis that typically affects children. A 4-year-old boy presented with a persistent rash on his left cheek for almost 2 years and was found to have primary cutaneous B-LBL. We report this case to emphasize that B-LBL should be in the differential diagnosis for an otherwise unimpressive persistent lesion in the head and neck region and review all reported pediatric cases of primary cutaneous B-LBL without extracutaneous involvement.

Mycosis Fungoides: Experience in a Pediatric Hospital

Mycosis fungoides (MF), the most common primary cutaneous T-cell lymphoma, is unusual in children.

OBJECTIVES

We aimed to describe the epidemiologic, clinical, histopathologic, and immunophenotypic characteristics of MF as well as treatments and course of disease in a pediatric case series.

MATERIAL AND METHOD

Data for all patients admitted to our pediatric hospital (Hospital Dr. J. P. Garrahan) in Argentina with a clinical and histopathologic diagnosis of MF between August 1988 and July 2014 were included.

RESULTS

A total of 14 patients were diagnosed with MF. The ratio of boys to girls was 1:1.33. The mean age at diagnosis was 11.23 years (range, 8-15 years). The mean time between onset and diagnosis was 3.5 years (range, 4 months-7 years). All patients had hypopigmented MF and 42% also presented the features of classic MF. Seven (50%) had the CD8⁺ immunophenotype exclusively. Seventy-eight percent were in stage IB at presentation. Phototherapy was the treatment of choice. Four patients relapsed at least once and skin lesions progressed in 3 patients. All patients improved.

CONCLUSIONS

MF is unusual in children. The hypopigmented form is the most common. Diagnosis is delayed because the condition is similar to other hypopigmented diseases seen more often in childhood. Although prognosis is good, the rate of recurrence is high, so long-term follow-up is necessary.

Primary cutaneous B-cell lymphomas with large cell predominance-primary cutaneous follicle center lymphoma, diffuse large B-cell lymphoma, leg type and intravascular large B-cell lymphoma

In this review, we present clinical features and detailed histopathologic, immunologic, and molecular information regarding primary cutaneous follicle center lymphoma and primary cutaneous diffuse large B-cell lymphoma, leg type which together represent two of the three most common types of primary cutaneous B-cell lymphoma recognized in the current WHO classification system.^1,2 Overall, B-cell lymphomas represent 19-27% of primary cutaneous lymphomas in most large European and American studies^3-6 and together, primary cutaneous follicle center lymphoma and primary cutaneous diffuse large B-cell lymphoma, leg type account for approximately 2/3 to ¾ of these cases.^5,7-11 Both subtypes can contain a high content of large B-lymphocytes, although most cases of primary cutaneous follicle center lymphomas exhibit a range in cell size and cytology. Intravascular large B-cell lymphoma, a less commonly-encountered EBV-negative primary cutaneous B-cell lymphoma composed of large cells, will be more briefly discussed in this report as well.

Primary Cutaneous Lymphomas in Children and Adolescents

Primary cutaneous lymphomas are rare in children and mostly represented by mycosis fungoides and CD30(+) lymphoproliferative disorders. Most pediatric cutaneous lymphomas have similar clinical/pathological features as their adult counterparts, particularly the T-cell subtypes. With regard to outcome, adult cutaneous mature T-cell lymphomas have a tendency to progression, while this appears to be relatively infrequent in children. The outcome of cutaneous B-cell lymphomas depends on subtype, with the B-lymphoblastic entity being associated with similar outcomes to precursor B acute lymphoblastic leukemia, while there are insufficient data on other entities. The diagnosis and treatment of these patients require a close collaboration between experienced pediatric pathologists, dermatologists, and oncologists. Prospective collection of longitudinal clinical and biological data from children with these rare lymphomas is needed to better understand their biological and clinical behavior and to ultimately discover the best therapeutic strategies.

Lymphomatoid Papulosis in Children and Adolescents: A Systematic Review

BACKGROUND

Lymphomatoid papulosis (LyP) is a lymphoproliferative disorder that is rare among adults and even rarer among children. In adults, LyP is associated with an increased risk of secondary lymphomas.

OBJECTIVE

The aim of this systematic review was to describe the clinical and histopathological features of LyP in children, to assess the risk of associated lymphomas, and to compare the disease to the adult form.

METHODS

A systematic review was conducted using the MEDLINE (PubMed), EMBASE, Scopus, and Cochrane databases from inception to June 2015. Articles were included if data were extractable from studies, case series, and single reports of pediatric LyP patients.

RESULTS

A total of 251 children and adolescents with LyP were identified, with the mean age at diagnosis being 9.3 ± 4.6 years (n = 187). The female to male ratio was 1:1.4, and the majority of children reported on were Caucasian (n = 74, 85.1 %). The predominant histologic subtype was type A (n = 106, 79.1 %). Clinically, LyP lesions presented as erythematous papules or nodules, appearing preferentially on the extremities and the trunk. LyP has to be differentiated from pityriasis lichenoides (PL) and primary cutaneous anaplastic large cell lymphoma (ALCL). PL and associated lymphomas were diagnosed before, with, and after LyP in 19 and 14 cases, respectively. Of the 14 subjects with associated lymphomas, two children developed systemic ALCL.

CONCLUSION

LyP has to be differentiated from ALCL to avoid erroneous treatments. Due to the increased risk of development of non-Hodgkin lymphomas, lifelong follow-up and proper patient counseling are warranted.