Granulomatous dermatitis in the context of chronic myelomonocytic leukemia: More than just reactive infiltrates. An illustrative case report with literature review.

Traditionally, skin involvement in chronic myelomonocytic leukemia (CMML) has been considered to be either specific (leukemia cutis) or non-specific, with granulomatous dermatitis included in the latter group. More recently, the true nature of the myeloid cells present in the cutaneous infiltrates of this theoretically reactive dermatitis is being clarified with the use of new molecular techniques such as next-generation sequencing. The same mutations in bone marrow (BM) myeloid neoplastic cells and in the cells of cutaneous infiltrates have been found. We present the case of a 77-year-old man who presented with spread and treatment-resistant skin granulomatous lesions previous to the diagnosis of CMML. The same clonal mutations in SRSF2, IDH1, and RUNX1 were found in both skin and BM with resolution of the lesions after the initiation of azacytidine. In conclusion, we report an exceptional case in which specific granulomatous cutaneous lesions have preceded and allowed the earlier diagnosis of an underlying CMML and a review of all previous similar cases in the literature, including molecular alterations.

Tumores de colisión en la piel: un hallazgo incidental en la mayoría de los casos. Estudio retrospectivo y revisión de la literatura / Collision tumours in skin: usually an incidental finding. A retrospective study with literature revision

Se denomina tumor de colisión (TC) a la coexistencia de dos o más neoplasias independientes en la misma resección. Suelen ser hallazgos incidentales en la piel, de patogénesis y prevalencia desconocidas, con pocas referencias en la literatura. Aquí mostramos un estudio retrospectivo de TC diagnosticados por un dermatopatólogo entre los años 2019-2022 en nuestro centro. Se han definido las lesiones de manera independiente y organizado cada colisión en categorías: benigno-benigno (BB), benigno-maligno (BM) y maligno-maligno (MM). Del total de 108 TC (1,4% de las biopsias totales del dermatopatólogo en ese periodo), se detecta que la colisión más frecuente es la formada entre BM (48,5%), con un carcinoma basocelular (CBC) como lesión maligna más frecuente de forma global y con un nevus melanocítico (NM) como lesión benigna principal. Se ha realizado el análisis estadístico de los resultados con el software Stata 14.2, detectando una diferencia estadísticamente significativa entre edad y tipo de colisión. (AU)

A collision tumour (CT) is a neoplastic lesion comprised of two or more distinct cell populations that maintain distinct borders. Mostly, these are incidental findings in skin biopsies, whose pathologic mechanism and prevalence remain unknown, with few references among literature. Here, we present a retrospective study of CT, diagnosed by a dermatopathologist in our hospital between 2019-2022. Lesions have been defined individually and organized into three categories: benign-benign (BB), benign-malignant (BM) and malignant-malignant (MM). A total of 108 CT were diagnosed (1,4% of the biopsies from the dermatopathologist during this period), from which BM was the most frequent collision (48,5%). Globally, basal cell carcinoma (BCC) was the main malignant lesion and melanocytic nevus (MN) the main benign lesion. We have used the software Stata 14.2 in order to analyse results, and we have detected a statistically significant difference between age and collision type. (AU)

Tumores de colisión en la piel: un hallazgo incidental en la mayoría de los casos. Estudio retrospectivo y revisión de la literatura / Collision tumours in skin: usually an incidental finding. A retrospective study with literature revision

Se denomina tumor de colisión (TC) a la coexistencia de dos o más neoplasias independientes en la misma resección. Suelen ser hallazgos incidentales en la piel, de patogénesis y prevalencia desconocidas, con pocas referencias en la literatura. Aquí mostramos un estudio retrospectivo de TC diagnosticados por un dermatopatólogo entre los años 2019-2022 en nuestro centro. Se han definido las lesiones de manera independiente y organizado cada colisión en categorías: benigno-benigno (BB), benigno-maligno (BM) y maligno-maligno (MM). Del total de 108 TC (1,4% de las biopsias totales del dermatopatólogo en ese periodo), se detecta que la colisión más frecuente es la formada entre BM (48,5%), con un carcinoma basocelular (CBC) como lesión maligna más frecuente de forma global y con un nevus melanocítico (NM) como lesión benigna principal. Se ha realizado el análisis estadístico de los resultados con el software Stata 14.2, detectando una diferencia estadísticamente significativa entre edad y tipo de colisión. (AU)

A collision tumour (CT) is a neoplastic lesion comprised of two or more distinct cell populations that maintain distinct borders. Mostly, these are incidental findings in skin biopsies, whose pathologic mechanism and prevalence remain unknown, with few references among literature. Here, we present a retrospective study of CT, diagnosed by a dermatopathologist in our hospital between 2019-2022. Lesions have been defined individually and organized into three categories: benign-benign (BB), benign-malignant (BM) and malignant-malignant (MM). A total of 108 CT were diagnosed (1,4% of the biopsies from the dermatopathologist during this period), from which BM was the most frequent collision (48,5%). Globally, basal cell carcinoma (BCC) was the main malignant lesion and melanocytic nevus (MN) the main benign lesion. We have used the software Stata 14.2 in order to analyse results, and we have detected a statistically significant difference between age and collision type. (AU)

Gorlin-Like Phenotype in a Young Girl With a De Novo PTCH2 Variant Mutation of Uncertain Significance.

ABSTRACT: Gorlin syndrome, also known as basal cell nevus syndrome, is an autosomal dominant genetic disorder that predisposes humans to tumors. In most cases, this syndrome results from inactivating mutations in the patched homologue 1 gene. Basal cell carcinomas are one of the main characteristics of this syndrome and serve as a major diagnostic criterion. Gorlin syndrome shows a variable phenotype, and recently, other less common mutations in the suppressor of fused homologue or patched homologue 2 genes have been documented in individuals with this syndrome. We present the case of a patient with early-onset basal cell carcinomas and a mild Gorlin syndrome phenotype, attributed to a de novo patched homologue 2 variant of uncertain significance, which has not been previously reported in the literature.

[Collision tumours in skin: usually an incidental finding. A retrospective study with literature revision]. / Tumores de colisión en la piel: un hallazgo incidental en la mayoría de los casos. Estudio retrospectivo y revisión de la literatura.

A collision tumour (CT) is a neoplastic lesion comprised of two or more distinct cell populations that maintain distinct borders. Mostly, these are incidental findings in skin biopsies, whose pathologic mechanism and prevalence remain unknown, with few references among literature. Here, we present a retrospective study of CT, diagnosed by a dermatopathologist in our hospital between 2019-2022. Lesions have been defined individually and organized into three categories: benign-benign (BB), benign-malignant (BM) and malignant-malignant (MM). A total of 108 CT were diagnosed (1,4% of the biopsies from the dermatopathologist during this period), from which BM was the most frequent collision (48,5%). Globally, basal cell carcinoma (BCC) was the main malignant lesion and melanocytic nevus (MN) the main benign lesion. We have used the software Stata 14.2 in order to analyse results, and we have detected a statistically significant difference between age and collision type.

Hydroa Vacciniforme Lymphoproliferative Disorder in a Young Spanish Woman: An Infrequent Case With Fatal Outcome.

ABSTRACT: Hydroa vacciniforme (HV) lymphoproliferative disorder is a rare NK/T-cell lymphoma mainly affecting children and with a clinical resemblance to HV, which is mostly reported in Latin American and some Asian countries. Overall, the mature T cell and NK-cell neoplasms are now grouped into 9 families based on diverse concepts: cell of origin/differentiation state, clinical scenario, disease localization, and cytomorphology. HV lymphoproliferative disorder is listed within the group of Ebstein Barr Virus-positive T-cell and NK-cell lymphoid proliferations and lymphomas of childhood according to the fifth edition of the World Health Organization Classification of mature lymphoid neoplasms. We report the extraordinary case of a 22-year-old white woman, native of Spain, first presented in 2016 when she started suffering from recurrent facial edema. Four years later, the disease progressed with lymph node spreading and a fatal outcome. Here, we describe the clinical and histological presentation of the lymphoma throughout its evolution. Cases like this can be difficult to classify posing a real challenge to clinicians and pathologists. So, it is vital to be aware of the rare presentation of this disease to be able to identify the clinical and histological picture to make a correct diagnosis and establish an early treatment.

Clinical, Histopathological and Molecular Spectrum of Cutaneous Lesions in Myelodysplastic Syndrome and Myeloproliferative Neoplasms (MDS/MPN): An Integrative Review.

Myeloid neoplasms and acute leukemias include different entities that have been recently re-classified taking into account molecular and clinicopathological features. The myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) category comprises a heterogeneous group of hybrid neoplastic myeloid diseases characterized by the co-occurrence of clinical and pathological features of both myelodysplastic and myeloproliferative neoplasms. The most frequent entity in this category is chronic myelomonocytic leukemia (CMML) which is, after acute myeloid leukemia (AML), the main myeloid disorder prone to develop cutaneous manifestations. Skin lesions associated with myelodysplastic and myeloproliferative neoplasms include a broad clinical, histopathological and molecular spectrum of lesions, poorly understood and without a clear-cut classification in the current medical literature. The aim of this review is to describe and classify the main clinical, histopathological and molecular patterns of cutaneous lesions in the setting of MDS/MPN in order to improve the diagnostic skills of the dermatologists, hematologists and pathologists who deal with these patients.

Essential thrombocythemia manifesting as livedoid and purpuric skin lesions: Report of two cases and literature review.

Essential thrombocythemia is a chronic myeloproliferative syndrome which usually runs its course as an asymptomatic elevated platelet count. Cutaneous manifestations secondary to microcirculation abnormalities are rare but can represent a helpful diagnostic clue in order to prevent major thromboembolic events. We report two cases of heterogeneous livedoid and "net-like" skin lesions in the context of essential thrombocythemia with identical histopathologic findings (medium-sized blood vessels with luminal obliteration by eosinophilic material, mostly positive for the platelet marker CD61, without vasculitis). In conclusion, we seek to raise awareness of the clinicopathological features of essential thrombocythemia to allow for prompt diagnosis and treatment.

Concurrent Presentation of Mycosis Fungoides and Primary Cutaneous Marginal Zone LPD: Clinicopathological Study of 4 Cases and Literature Review.

BACKGROUND: Mycosis fungoides is rarely associated to B-cell malignancies, and the few reported cases are mainly internal lymphomas involving secondarily the skin (ie, chronic lymphocytic leukemia). OBJECTIVES: The aim of our study is to describe the clinical and histopathological features of 4 patients presenting with 2 concurrent primary cutaneous lymphomas and review the pertinent literature. METHODS: We identified 4 cases of concurrent primary cutaneous lymphomas in our institutions. An extracutaneous lymphoma was ruled out on the basis of a complete work out. We performed a PubMed search to identify reported cases of primary cutaneous composite or concurrent lymphomas. RESULTS: Eleven cases of primary cutaneous concurrent lymphomas have been described in the literature. Counting all together (our cases and the cases previously described in the literature), mycosis fungoides was the most frequent primary cutaneous T-cell lymphoma (TCL) (13/15), followed by 1 case of peripheral TCL-NOS and 1 case of subcutaneous panniculitis-like TCL. Regarding the associated primary cutaneous B-cell lymphomas, 8/15 cases consisted of low-grade B-cell lymphomas [that is, 5 marginal zone lymphoma (in the most recent classification reclassified as marginal zone lymphoproliferative disorder, MZLD, 2 follicular-center B-cell lymphoma (primary cutaneous follicle-center lymphoma) and 1 low-grade NOS B-cell lymphoma]; 4/15 were associated to Epstein-Barr virus; 1 case consisted of a methotrexate-associated lymphoproliferative disease, and 2 cases consisted of primary cutaneous diffuse large B-cell lymphoma-leg type. CONCLUSIONS: Primary cutaneous concurrent lymphomas are exceptional. Clinicopathological correlation and a complete workout to reach the correct diagnosis may guide the appropriate treatment in each case.

Brentuximab vedotin in the treatment of cutaneous T-cell lymphomas: Data from the Spanish Primary Cutaneous Lymphoma Registry.

BACKGROUND: Brentuximab vedotin (BV) has been approved for CD30-expressing cutaneous T-cell lymphoma (CTCL) after at least one previous systemic treatment. However, real clinical practice is still limited. OBJECTIVES: To evaluate the response and tolerance of BV in a cohort of patients with CTCL. METHODS: We analysed CTCL patients treated with BV from the Spanish Primary Cutaneous Lymphoma Registry (RELCP). RESULTS: Sixty-seven patients were included. There were 26 females and the mean age at diagnosis was 59 years. Forty-eight were mycosis fungoides (MF), 7 Sézary syndrome (SS) and 12 CD30+ lymphoproliferative disorders (CD30 LPD). Mean follow-up was 18 months. Thirty patients (45%) showed at least 10% of CD30+ cells among the total lymphocytic infiltrate. The median number of BV infusions received was 7. The overall response rate (ORR) was 67% (63% in MF, 71% in SS and 84% in CD30 LPD). Ten of 14 patients with folliculotropic MF (FMF) achieved complete or partial response (ORR 71%). The median time to response was 2.8 months. During follow-up, 36 cases (54%) experienced cutaneous relapse or progression. The median progression free survival (PFS) was 10.3 months. The most frequent adverse event was peripheral neuropathy (PN) (57%), in most patients (85%), grades 1 or 2. CONCLUSIONS: These results confirm the efficacy and safety of BV in patients with advanced-stage MF, and CD30 LPD. In addition, patients with FMF and SS also showed a favourable response. Our data suggest that BV retreatment is effective in a proportion of cases.

Granulomatous Dermatitis Heralding Myelodisplastic/Myeloproliferative Neoplasms. Neoplastic or Reactive Cells? A Study of 2 Cases.

ABSTRACT: Skin manifestations in the context of underlying hematological malignancies are well known and not an infrequent clinical finding. They can represent specific neoplastic infiltrates or be considered as reactive. In the latter group, where granulomatous dermatitis is included, controversy has emerged recently. According to newly reported data, the histiocytes comprising these granulomata can carry the same molecular alterations found in the primary process. Moreover, the skin manifestations in these patients are sometimes the initial clue for the diagnosis of the underlying malignancy. We present here 2 cases with granulomatous skin infiltrates preceding the diagnosis of myelodysplastic/myeloproliferative neoplasms. In one of them, the same IDH2 mutation was detected in granulomatous lesions on the skin and in the bone marrow. This was performed by pyrosequencing instead of next-generation sequencing, with improved cost-effectiveness.

[Papular mycosis fungoides in elderly: Report of two cases]. / Micosis fungoide papular en el anciano: a propósito de 2 casos.

Papular mycosis fungoides (MF) is an uncommon clinical variant of early MF without prognostic implications that follows an indolent course over years. It is characterized by the presence of multiple, small, pruritic, flat-topped, erythematous papules, often presenting as a nonspecific papular eruption which makes early diagnosis difficult. We describe two cases of elderly patients with papular MF, a probably underdiagnosed entity, which causes a significant deterioration in quality of life of patients who may benefit from specific treatments such as phototherapy.

Discoid Lupus Erythematosus Presenting With Disfiguring Acneiform Plaques: A Diagnostic Challenge.

ABSTRACT: Hypertrophic and acneiform forms are very rare variants of discoid lupus erythematosus (DLE), which can suppose a diagnostic and therapeutic challenge. We present a South American woman with facial disfiguring lesions of 7 years of evolution with clinical and histopathological characteristic of both hypertrophic and acneiform DLE. No criteria for systemic lupus erythematosus were present in the patient. To the best of our knowledge, no patients with concomitant hypertrophic and acneiform DLE have been previously reported in the literature.

Atypical BCL6/GATA3+ Primary Cutaneous Acral CD8-Positive T-Cell Lymphoma: A Diagnostic Challenge.

ABSTRACT: Primary cutaneous acral CD8-positive T-cell lymphoma consists of slow-growing nodules in acral sites with a histopathology, suggesting high-grade lymphoma despite the indolent clinical course. It has been recently included in WHO-EORTC classification for primary cutaneous lymphomas as a provisional entity. A correct diagnosis of this entity is important because its differential diagnosis include more aggressive cutaneous lymphomas. We present a 53-year-old woman with an indolent solitary nodule on her right leg, which histopathologically showed features of CD8-positive T-cell lymphoma, although with some peculiarities, including epidermotropism, absence of CD68 expression, and positivity for GATA3 and Bcl6 in neoplastic cells. This case could contribute to better define the spectrum of this rare cutaneous lymphoma.

Flame Figures in Linear Immunoglobulin A Bullous Dermatosis Secondary to Parvovirus B19 Infection.

ABSTRACT: Flame figures represent a characteristic but nondiagnostic histological finding in eosinophilic dermatoses. Some bullous autoimmune diseases with a predominant eosinophilic infiltrate, such as bullous pemphigoid, pemphigoid gestationis, and pemphigus vegetans, may show them. However, it is rare to find them in predominant neutrophilic bullous dermatoses such as linear immunoglobulin A. We present a 60-year-old man with a history of chronic urticaria, which presented a bullous disease after an acute parvovirus B19 infection. The histological findings showed an exceptional linear immunoglobulin A bullous dermatosis with an eosinophilic infiltrate in the dermis forming "flame figures." The clinical and histopathological findings for this entity may be identical to those of other dermatoses. For this reason, combining these findings with direct immunofluorescence analysis is essential for correct diagnosis of this bullous disease.

[Painful nodules on the soles in a pediatric patient: A diagnostic challenge]. / Nodulos plantares dolorosos tras ejercicio intenso en paciente pediátrica: Un reto diagnóstico.

INTRODUCTION: Idiopathic Palmoplantar Eccrine Hidradenitis (IPPH) is a rare neutrophilic derma tosis, with painful erythematous nodules of sudden onset in the plantar or palmoplantar region, in children without other underlying diseases. OBJECTIVE: To present a case that shows the main clinical and histological characteristics of this entity. CLINICAL CASE: 11-year-old girl with a 48-hours history of painful erythematous-violaceous nodules on the right foot plant associated with fever of up to 38.2 °C, with no history of interest except hyperhidrosis and intense exercising on previous days. Given the clinical suspicion of IPPH, a skin biopsy was performed, which showed inflammatory neutrophil infiltration around eccrine sweat glands and neutrophilic abscesses, confirming the diagnosis. Oral NSAIDs and rest were prescribed, with resolution of the lesions in 7 days. CONCLUSIONS: This case demonstrates the most important aspects of this entity, in many cases underdiagnosed, since it can be confused with other pathologies that occur with painful acral nodules, but have different pathogenic and therapeutic implications. To properly identify the IPPH allows preventing an unnecessary alarm, both patients and their parents, as in dermatologists and pediatricians themselves.