Idiopathic eruptive macular pigmentation in a pediatric patient and a review of the literature

Idiopathic eruptive macular pigmentation (IEMP) is a rare, benign, self-resolving melanosis consisting of hyperpigmented macules typically on the face, trunk, and extremities that can occur in children and adolescents and often presents a diagnostic conundrum. We report a case involving an 8-year-old female whose previous clinical presentation was concerning for an atypical presentation of cutaneous mastocytosis or neurofibromatosis. The clinical and histopathologic evaluation was consistent with the diagnosis of IEMP, and no active intervention was pursued. Our accompanying literature review serves to better characterize this condition, highlight key diagnostic features, and emphasize the tendency for spontaneous resolution to avoid unnecessary treatments with limited clinical efficacy.

Evaluation of Ki67, Bax, Bcl-2 and KIT in canine cutaneous mast cell tumours and their relationship with histopathology and prognosis

Canine cutaneous mast cell tumours (CCMCTs) are common in dogs and exhibit many unpredictable behaviors. This study aimed to encourage pathology laboratories in developing countries to routinely assess prognosis by applying commonly used histopathological grading systems and immunohistochemistry (IHC) markers. We performed histological grading according to both the Patnaik and Kiupel systems, determined the mitotic count (MC) and carried out IHC for the detection of Ki67, Bax, Bcl-2 and KIT in 54 CCMCT cases. MC was associated with both grading systems in terms of survival following diagnosis and prognostic factors differed among cases categorized by the cut-off value of 5. KIT patterns were associated with grading systems and MC. The cohort with pattern II had a lower survival rate than those with patterns I and III. Ki67 was associated with survival when evaluated over the cut-off value of 0.018. Bax expression was associated with both grading systems. Median survival time was longer in patients with lower Bax expression level. Immunohistochemical detection of KIT, Ki67 and Bax improves histopathology in predicting the prognosis. If IHC is unavailable, reports regarding MC and values from both grading systems are the most effective, convenient and cost-effective way to provide the most reliable prognostic data and guidance for the clinicians.

[MACULOPAPULAR CUTANEOUS MASTOCYTOSIS HARBORING A KIT MUTATION (ASP419DEL): A CASE REPORT]

A 2-year-old, male patient presented with an 18-month history of scattered, brown macules and nodules up to 2 cm in size on his trunk and extremities. These macules were accompanied by pruritus and were positive for Darier's sign. A skin biopsy of a brown macule on the left thigh revealed a dense accumulation of CD117-positive, round or oval cells with amphophilic cytoplasm within the upper to middle dermis. The patient was otherwise healthy and had normal laboratory and imaging test results. Sequence analysis of genomic DNA from a skin biopsy demonstrated the presence of an Asp419del mutation in exon 8 of the KIT gene. Based on these findings, maculopapular cutaneous mastocytosis (MPCM) was diagnosed. The patient received H 1-antihistamine. Although the pruritus resolved, the brown macules remained for one year after the initial treatment. To the best of our knowledge, only three cases of cutaneous mastocytosis (CM) with an Asp419del mutation, including the present case, have been reported in the Japanese literature to date; moreover, while the previous two cases were of DCM, the present case was the first instance of MPCM. Normally, the symptoms of childhood-onset MPCM are dormant until puberty. However, a recent study reported that many MPCM patients may experience persistent or exacerbated symptoms. The present study therefore evaluated 53 Japanese cases of childhood onset MPCM with a KIT gene mutation and discussed the patients' clinical outcomes.

An Unusual Transition from Cutaneous to Systemic Mastocytosis in a Pediatric Patient

Background: Cutaneous mastocytosis (CM) occurs when abnormal mast cells accumulate in the skin, whereas in systemic mastocytosis (SM), accumulation also occurs in other tissues. A transition from CM to SM is an atypical occurrence in pediatric patients. Case Presentation: An 8-month-old female presented with a 3-month history of whole body hyperpigmented macules with a normal serum tryptase level, consistent with a diagnosis of CM. At age 2.5 years, cutaneous lesions increased and repeat serum tryptase levels were elevated. Subsequent positive peripheral blood KIT D816V mutation testing furthered concern for a monoclonal mast cell disorder; therefore, prompting a bone marrow biopsy which was consistent with a diagnosis of SM. Conclusion: Our case depicts the possible transition from CM to SM in a pediatric patient. Despite an initial presentation consistent with a diagnosis of CM, watchful monitoring for signs and symptoms indicative of systemic involvement may be warranted in some pediatric patients.

Cutaneous mastocytosis in 8 young dogs and review of literature

Cutaneous mastocytosis (CM) is a rare condition in young dogs characterized by multicentric cutaneous proliferation of neoplastic mast cells. Clinical data from 8 dogs that met inclusion criteria (age of onset less than 1.5 years, greater than 3 lesions) were obtained via a standardized survey. Biopsy samples were classified by the Kiupel/Patnaik grading systems and analyzed for c-KIT mutations. The median age of onset was 6 months (range: 2-17 months). Dogs had 5 to more than 50 lesions characterized as nodules, plaques, and papules. Seven dogs were pruritic. Clinical staging in 2 dogs did not reveal visceral involvement. No dogs had systemic illnesses at diagnosis. Histologically, CM was similar to cutaneous mast cell tumor (cMCT). Two dogs had neoplasms classified as high-grade/grade II while 6 dogs had low-grade/grade II neoplasms. No dogs had mutations in c-KIT exons 8 and 11. Treatment included antihistamines (8/8), corticosteroids (7/8), lokivetmab (3/8), and toceranib (1/8). Six dogs were alive with lesions at the end of the study with a median follow-up time of 898 days, while 2 dogs were euthanized. In dogs with high-grade/grade II neoplasms, one continued to develop lesions at 1922 days post-diagnosis, while the other dog was euthanized at 56 days post-diagnosis. One dog was euthanized 621 days post-diagnosis due to rupture of a neoplasm. CM occurs in young dogs and is histologically indistinguishable from cMCT. Current histologic grading systems did not apply uniformly to the dogs of the study and further studies are needed.

A Review of the Clinical Features and Management of Systemic Congenital Mastocytosis through the Presentation of An Unusual Prenatal-Onset Case

Mastocytosis is a heterogeneous group of rare hematological disorders that can occur in infancy. We report a 16-year-old girl who presented with an aggressive form of systemic congenital mastocytosis, associated with a significant global developmental delay, deafness, and multiple anomalies. At 4 years of age, she developed a germinoma presenting as an invasive spinal mass. Extensive cytogenetic, metabolic, and molecular genetic studies that included whole-exome sequencing studies revealed a KIT alteration (NM_000222.3(KIT):c2447A > 7 pAsp816Val) and likely pathogenic variant in the DNA from peripheral blood and skin lesions. C-kit was also found to be overexpressed in the spinal tumor cells. We compared the features of this child to those of six previously reported pediatric patients with cutaneous mastocytosis, microcephaly, microtia, and/or hearing loss reported in OMIM as mastocytosis, conductive hearing loss, and microtia (MIM 248910), for which the etiology has not yet been determined. This report extends the currently recognized spectrum of KIT-related disorders and provides clues as to the potential etiology of a syndromic form of congenital mastocytosis. International efforts to understand the benefits of long-term targeted therapy with tyrosine kinase inhibitors for this KIT-altered rare disease should continue to be evaluated in clinical trials.

Cutaneous Lesions of Mastocytosis: Mast Cell Count, Morphology, and Immunomolecular Phenotype

ABSTRACT

Mastocytosis is a condition characterized by accumulation of clonal mast cells (MCs) that often involves the skin. Pathologists are often challenged with skin biopsies with a question of cutaneous lesions of mastocytosis (CLM) including cutaneous mastocytosis, mastocytosis in the skin, or systemic mastocytosis. The histopathological criteria for CLM remain poorly defined due to heterogeneity of the published literature and the lack of comparative prospective studies. MC count is greatly influenced by detection and counting techniques, criteria for viable MCs used, anatomical location biopsied, and the dermal level that is analyzed. Although MC numbers in CLM can be significantly higher compared with healthy controls and a patient with other inflammatory skin diseases, in some instances, considerable overlap exists. Based on the largest studies published, it is suggested that a number of MCs between 75 and 250 MCs/mm 2 are a range in which CLM should be considered and, above 250 MC/mm 2 , a diagnosis of CLM can be made. A recent study showed a high specificity of >95% of a MC count >139 MC/mm 2 compared with patients with other inflammatory skin diseases. Noteworthy, the total number and percentage of MCs is significantly higher in children compared with adults, particularly in polymorphic maculopapular cutaneous mastocytosis. In difficult cases, ancillary techniques such as D816V mutation analysis on formalin-fixed paraffin-embedded tissue have a high sensitivity and specificity. There is no enough evidence that immunohistochemistry of CD25, CD2, or CD30 has any additional value in the diagnosis, subtyping, or clinical course of mastocytosis.

Radiotherapy-Associated Cutaneous Mastocytosis in a Patient With Breast Carcinoma. Case Report and Review of the Literature

ABSTRACT

Mast cell skin disease is rarely described after external beam radiation therapy in patients with breast carcinoma, with only 7 previous reports in the literature. Skin changes typically occur within (but are not limited to) the radiation field. We present a 64-year-old woman with postradiotherapy cutaneous mastocytosis on the left breast and adjacent chest wall. The clinical and laboratory findings in all reported patients, including the current case, are reviewed. No clear mechanism has been presented to explain disease pathogenesis; although, mast cell accumulation secondary to local mediators produced in response to radiation damage and/or koebnerization phenomenon have been proposed. Cutaneous/systemic mastocytosis is not widely recognized and may be underdiagnosed in the setting of postradiation for breast cancer. It is important for clinicians and pathologists to be aware of this diagnosis for patients presenting with rashes after radiotherapy.

[A CHILD CASE OF DIFFUSE CUTANEOUS MASTOCYTOSIS]

Cutaneous mastocytosis (CM) usually appears in childhood and improves substantially before adolescence. The c-KIT mutation of D816V is present in 36% and 20% of patients with childhood-onset CM and diffuse cutaneous mastocytosis (DCM), respectively. In some cases of childhood-onset DCM, the disease can progress to systemic mastocytosis; in others, it resolves spontaneously. Thus, assessing the prognosis is difficult. Herein, we described a case of DCM in an 11-month-old, male patient without a c-KIT mutation. The patient presented with dark brown macules and sporadic erythema topped by bullous lesions. A skin biopsy of the macule on the abdomen revealed accumulation of mast cells which were round to oval-shaped with amphophilic cytoplasm within the upper dermis. The patient had received H1 inhibitor until age 3 years and continued to experience blisters on the trunk. However, no severe symptoms, such as anaphylaxis, occurred. Included in this manuscript is a review of previous reports of childhood-onset DCM in Japan and cases specifically seen at our dermatology clinic.

Telangiectasia Macularis Eruptiva Perstans of the Scalp Mimicking Angiosarcoma

ABSTRACT

We present a case of a 74-year-old man with marked photodamage who was ultimately diagnosed with telangiectasia macularis eruptiva perstans (TMEP) of the scalp. The diagnosis was made more difficult because of the clinical and histological similarity of this case with an early angiosarcoma. TMEP is a benign and indolent rare subtype of cutaneous mastocytosis presenting clinically with red-brown telangiectatic macules, usually symmetrically distributed over the trunk and extremities. Although most cases are limited to the skin, systemic involvement can occur, and this can be a potentially life-threatening disease. Although also rare, in contrast to TMEP, cutaneous angiosarcoma is a highly malignant vascular tumor with a poor prognosis. This case highlights the importance of including TMEP on the differential diagnosis where vascular lesions of the scalp are observed.

A New Digital Method for Counting Mast Cells in Cutaneous Specific Lesions of Mastocytosis: A Series of Adult Cases of Mastocytosis With Clinical-Pathological Correlations

ABSTRACT

Cutaneous mastocytosis is characterized by the abnormal accumulation of mast cells in the skin. However, mast cell counting is not always easy and reproducible with classical methods. This work aims to demonstrate the reliability, usability, and virtues of a new software used on digital tablets for counting mast cells in cutaneous specific lesions of mastocytosis, to assess differences in mast cell counts between clinical subtypes of mastocytosis in the skin, and to consider the feasibility of applying a diagnostic mast cell count cutoff to urticaria pigmentosa, which is the most frequent form of cutaneous mastocytosis. Using a new digital tablet software that was accessible by multiple observers through its own wireless network and allowed high resolution of the image without data compression, we counted the number of mast cells on slides of patients and control skins immunostained for CD117. We found that our counting method was highly reproducible and that the new software allowed very quick counting. We evidenced strong differences in the mast cell count between most of the clinical subtypes of mastocytosis in the skin. However, when applied to a subset of patients with urticaria pigmentosa, a diagnostic cutoff in the mast cell count lacked sensitivity. Thus, our digital method for counting CD117-immunostained mast cells was highly accurate and was of a significant value for the diagnosis of mastocytosis in the skin. However, some subtypes with low mast cell counts will still require the application of additional diagnostic criteria.

[An infant with macules and papules]

Polymorphic maculopapular cutaneous mastocytosis (PMCM) is caused by proliferation of mast cells in the skin. It is commonly seen in infants. Although mastocytosis usually only affects the skin, systemic mastocytosis should be ruled out in cases with extensive presentation. PMCM resolves spontaneously before puberty in most cases. A 6-month-old male presented with asymptomatic cutaneous erythematous patches all over the skin. Darier's sign was positive. A diagnosis of polymorphic maculopapular cutaneous mastocytosis was made. Because of the extensive skin lesions, the patient was referred to a paediatrician. Tryptase levels were elevated but blood tests did not suggest systemic involvement. The parents were given an EpiPen Jr because of increased risk of anaphylactic shock.

Risk and management of patients with mastocytosis and MCAS in the SARS-CoV-2 (COVID-19) pandemic: Expert opinions

The coronavirus disease 2019 (COVID-19) (caused by severe acute respiratory syndrome coronavirus 2) pandemic has massively distorted our health care systems and caused catastrophic consequences in our affected communities. The number of victims continues to increase, and patients at risk can only be protected to a degree, because the virulent state may be asymptomatic. Risk factors concerning COVID-19-induced morbidity and mortality include advanced age, an impaired immune system, cardiovascular or pulmonary diseases, obesity, diabetes mellitus, and cancer treated with chemotherapy. Here, we discuss the risk and impact of COVID-19 in patients with mastocytosis and mast cell activation syndromes. Because no published data are yet available, expert opinions are, by necessity, based on case experience and reports from patients. Although the overall risk to acquire the severe acute respiratory syndrome coronavirus 2 may not be elevated in mast cell disease, certain conditions may increase the risk of infected patients to develop severe COVID-19. These factors include certain comorbidities, mast cell activation-related events affecting the cardiovascular or bronchopulmonary system, and chemotherapy or immunosuppressive drugs. Therefore, such treatments should be carefully evaluated on a case-by-case basis during a COVID-19 infection. In contrast, other therapies, such as anti-mediator-type drugs, venom immunotherapy, or vitamin D, should be continued. Overall, patients with mast cell disorders should follow the general and local guidelines in the COVID-19 pandemic and advice from their medical provider.

[Cutaneous Manifestations in Mastocytosis: Update]

INTRODUCTION

Mastocytosis is characterized by the clonal expansion of morphological and immunophenotypically abnormal mast cells in different organs. The skin is the most frequently affected tissue. Virtually all children and more than 80% of adult patients with mastocytosis show cutaneous lesions.

MATERIAL AND METHODS

The present article describes the symptoms and signs in cutaneous mastocytosis, based on the review of recently published international consensus guidelines.

DISCUSSION

According to the 2016 World Health Organization classification, mastocytosis can be divided in cutaneous mastocytosis, systemic mastocytosis and mast cell sarcoma. Cutaneous mastocytosis is subclassified in three subtypes: maculopapular cutaneous mastocytosis, diffuse cutaneous mastocytosis and cutaneous astocytoma. Telangiectasia macularis eruptiva perstans is no longer considered a distinct entity.

CONCLUSION

Based on the age of onset, cutaneous manifestations of mastocytosis can be variable. The classification of cutaneous mastocytosis has recently been updated. Typically, in patients with childhood-onset mastocytosis, the disease occurs as cutaneous mastocytosis and shows spontaneous resolution around puberty. In contrast, adult patients, despite having also cutaneous lesions, often show systemic involvement and the course of the disease is usually chronic.

[Cutaneous mastocytosis - update and clinical guidelines]

Mastocytosis is a rare and multifaceted disease group characterized by mast cell accumulation in the skin and/or internal organs. In its most common form solitary or widespread, often itchy, red-brown skin lesions appear in childhood or during adulthood (cutaneous mastocytosis). The skin lesions are not always easy to recognize by medical professionals; hence, a correct diagnosis is often delayed. In children, the lesions tend to resolve before puberty, whereas most post-adolescent patients experience a chronic course combined with extra-cutaneous mast cell infiltration (systemic mastocytosis). Therefore, adult patients with cutaneous mastocytosis should be examined for signs of systemic involvement. This article describes the symptoms and signs in cutaneous mastocytosis, and provides guidelines based on international consensus documents. In addition, a newly updated classification of different forms of cutaneous mastocytosis is given.

Copper Regulates Maturation and Expression of an MITF:Tryptase Axis in Mast Cells

Copper has previously been implicated in the regulation of immune responses, but the impact of this metal on mast cells is poorly understood. In this article, we address this issue and show that copper starvation of mast cells causes increased granule maturation, as indicated by higher proteoglycan content, stronger metachromatic staining, and altered ultrastructure in comparison with nontreated cells, whereas copper overload has the opposite effects. In contrast, copper status did not impact storage of histamine in mast cells, nor did alterations in copper levels affect the ability of mast cells to degranulate in response to IgER cross-linking. A striking finding was decreased tryptase content in mast cells with copper overload, whereas copper starvation increased tryptase content. These effects were associated with corresponding shifts in tryptase mRNA levels, suggesting that copper affects tryptase gene regulation. Mechanistically, we found that alterations in copper status affected the expression of microphthalmia-associated transcription factor, a transcription factor critical for driving tryptase expression. We also found evidence supporting the concept that the effects on microphthalmia-associated transcription factor are dependent on copper-mediated modulation of MAPK signaling. Finally, we show that, in MEDNIK syndrome, a condition associated with low copper levels and a hyperallergenic skin phenotype, including pruritis and dermatitis, the number of tryptase-positive mast cells is increased. Taken together, our findings reveal a hitherto unrecognized role for copper in the regulation of mast cell gene expression and maturation.

Telangiectasia Macularis Eruptiva Perstans: Report of Three Cases

Telangiectasia macularis eruptiva perstans (TMEP) is a rare, heterogeneous disease of mast cell proliferation. The variable clinical presentation of TMEP, coupled with its rarity, makes the recognition and diagnosis of this disease difficult and challenging for clinicians. The histopathologic findings with hematoxylin and eosin staining that distinguish TMEP from a normal skin biopsy can be so subtle that confirmation of the diagnosis with additional special stains (c-Kit, Giemsa, toluidine blue) is strongly recommended. We describe three cases that highlight the variable clinical presentation of TMEP. One patient experienced only a localized skin manifestation, another an aggressive clinical course with systemic involvement, and a third diffuse skin involvement with mild fatigue, muscle pain, and weight gain.

[Diffuse cutaneous mastocytosis of an infant: A case report]

Mastocytosis is a group of diseases related to abnormal accumulation and proliferation of mast cells in one or more organs. They may be associated with an acquired point mutation and the activation of the receptor tyrosine-kinase c-KIT of CFS (mast cell growth factor). The clinical manifestations are varied and secondary to the release of mast cell mediators and/or infiltration of various organs. There are two main types of mastocytosis: pure cutaneous mastocytosis and systemic mastocytosis when more than two organs are involved in mast cell infiltration (bone marrow, gastrointestinal tract, bone, liver and spleen, lymph nodes). Mastocytosis affects children in two thirds of cases, most frequently as an isolated cutaneous form. The most common clinical form in children is urticaria pigmentosa and solitary mastocytoma; bullous diffuse mastocytosis is rare. We report the case of an 8-month-old infant who presented with a diffuse pruritic bullous eruption. The histology and immunohistochemistry results were suggestive of mastocytosis. A serum tryptase test yielded positive results. Laboratory investigations did not identify systemic involvement. The patient was given antihistamine H1 medication and local care. Advice regarding the disease was offered to the parents. The course of the disease was marked by a decrease in the number of blisters and attenuation of the pruritus at the 6-month follow-up. This observation emphasizes the importance of awareness of this rare entity, which should be considered in all cases of bullous dermatosis in children, thereby allowing for early treatment.

Cellular Proliferation in Canine Cutaneous Mast Cell Tumors: Associations with c-KIT and Its Role in Prognostication

Canine cutaneous mast cell tumor (MCT) is a common neoplastic disease in dogs. Due to the prevalence of canine MCTs and the variable biologic behavior of this disease, accurate prognostication and a thorough understanding of MCT biology are critical for the treatment of this disease. The goals of this study were to evaluate and compare the utility of the proliferation markers Ki67, proliferating cell nuclear antigen (PCNA), and argyrophilic nucleolar organizing region (AgNOR) as independent prognostic markers for canine MCTs and to evaluate the use of these markers in combination, as each marker assesses different aspects of cellular proliferation. An additional goal of this study was to evaluate the associations between cellular proliferation and c-KIT mutations and between cellular proliferation and aberrant KIT protein localization in canine MCTs. Fifty-six MCTs treated with surgical excision alone were included in this study. Each MCT was evaluated for Ki67 expression, PCNA expression, and KIT protein localization using immunohistochemistry; for AgNOR counts using histochemical staining; and for the presence of internal tandem duplication c-KIT mutations using polymerase chain reaction amplification. In this study, increased Ki67 and AgNOR counts were both associated with significantly decreased survival. On the basis of these results, we recommend that the evaluation of cellular proliferation, including evaluations of both Ki67 expression and AgNORs, should be routinely used in the prognostication of canine MCTs. Additionally, the results of this study show that MCTs with aberrant KIT protein localization or internal tandem duplication c-KIT mutations are associated with increased cellular proliferation, further suggesting a role for c-KIT in the progression of canine MCTs.

Variation among Pathologists in the Histologic Grading of Canine Cutaneous Mast Cell Tumors with Uniform Use of a Single Grading Reference

Ten veterinary pathologists independently assigned histologic grades to the same 60 canine cutaneous mast cell tumors using the Patnaik classifications. The degree of agreement in grading among the pathologists was compared with the degree of agreement among the same pathologists in a previous study, in which each pathologist used the reference for grading that he/she uses routinely. Mean agreement improved significantly from 50.3% to 62.1% with uniform use of the Patnaik classifications ( P = 0.00001), suggesting that there is value in uniform application of a single grading scheme for canine cutaneous mast cell tumors. Agreement among pathologists was still not 100%, suggesting that a more objective grading scheme should be developed and that other histologic indicators of prognosis should be investigated.

Overexpression of p16(INK4a) in Mastocytosis (Urticarial Pigmentosa)

The expression of p16(INK4a) has been reported to induce cell-cycle arrest and cellular senescence. The p16(INK4a) expression has never been examined in human mast cells and mastocytosis. We immunohistologically examined the expression of p16(INK4a) and tryptase in 5 normal human skin and 4 mastocytosis. In normal mast cells, only 5.9 ± 3.4 (mean ± standard deviation) % of tryptase-positive mast cells coexpressed p16(INK4a). However, significantly higher percentage (86.0 ± 14.1%) of tryptase-positive tumor cells was immunoreactive to p16(INK4a) in all of 4 mastocytosis. The p16(INK4a) overexpression may induce the senescence of neoplastic mast cells to undergo spontaneous regression of mastocytosis.

Acquired cutis laxa associated with cutaneous mastocytosis

Cutis laxa is characterized by dramatic wrinkling of skin that is lacking in elasticity due to inherent defects in dermal elastic fibers. Cutis laxa can be caused by genetic and metabolic disorders. It can also be acquired, possibly resulting from inflammatory processes with destruction of elastic fibers. This report describes a 26-year old woman who developed acquired cutis laxa and cutaneous mastocytosis leading to premature aging. She represents a unique co-occurrence of these two separate disease entities. To our knowledge, there has been only one published case report of acquired cutis laxa occurring in association with urticaria pigmentosa in a 4-year old girl. Our case would be a second case that exhibits the coexistence of these two disorders in an adult female.

Assessment of clinical findings, tryptase levels, and bone marrow histopathology in the management of pediatric mastocytosis

BACKGROUND

The management of children with pediatric mastocytosis poses a challenge. This is because there is limited information as to the application of clinical and laboratory findings and bone marrow histopathology as they relate to medical intervention and communication.

OBJECTIVE

We sought to examine clinical aspects of pediatric mastocytosis in relationship to serum tryptase levels and bone marrow pathology to provide practical guidance for management.

METHODS

Between 1986 and 2012, 105 children were evaluated at the National Institutes of Health. Organomegaly was confirmed by means of ultrasound. Baseline tryptase levels and at least 1 subsequent tryptase measurement was available in 84 and 37 of these children, respectively. Fifty-three children underwent a bone marrow examination. These data were used to examine relationships between clinical findings, tryptase levels, and marrow histopathology.

RESULTS

In patients with high tryptase levels and severe mediator symptoms, all with organomegaly had systemic disease, and none without organomegaly had systemic disease. Serum tryptase levels differed significantly between patients with urticaria pigmentosa and those with diffuse cutaneous (P < .0001) and systemic mastocytosis (P < .0001) and in all 3 categories versus control subjects (P < .0001). Tryptase levels and symptoms decreased over time in most patients, and tryptase levels correlated with bone marrow mast cell burden in patients with systemic mastocytosis (P < .0001). There was a significant relationship between clinical resolution and the percentage decrease in tryptase levels (P = .0014).

CONCLUSIONS

The majority of children experienced major or complete disease resolution (57%), whereas the remainder exhibited partial improvement. Organomegaly was a strong indicator of systemic disease. Serum tryptase levels furthered classification and reflected clinicopathologic findings, while sequential tryptase measurements were useful in supplementing clinical judgment as to disease course.

Two Cases of Telangiectasia Macularis Eruptiva Perstans Demonstrated by Immunohistochemistry for C-Kit (CD 117)

Telangiectasia macularis eruptiva perstans (TMEP) is an uncommon form of cutaneous mastocytosis that occurs exclusively in adults. Histologically, TMEP presents with scattered mast cells lined up around the dilated capillaries and venules of the superficial vascular plexus. In some cases, the number of mast cells falls within the range observed in normal skin and therefore cannot be detected by routine histologic examination. We used immunohistochemical staining for c-kit (CD 117) for the definitive diagnosis in two patients with TMEP. One of them was successfully treated with topical application of pimecrolimus.

Cutaneous mastocytosis, problems of clinical diagnosis of four cases

Mastocytosis is a rare disease characterized by a pathological increased of mast cells in one or more tissues, particularly in the skin, bone marrow, liver, spleen, lymph nodes and gastrointestinal tract. Cutaneous mastocytosis represents over 90% of cases found with predilection in children. The aim of the paper was to summarize the authors' clinical, histopathological and immunohistochemical observations on patients with cutaneous mastocytosis. We present four cases of cutaneous mastocytosis, sporadic form, customized by clinical presentation and age of onset: two installed in the neonatal period, a case with onset in infancy and another in adulthood. For the assessment of the severity and the effectiveness of the treatment, we used SCORMA Index. We performed in each patient histopathological examination of the skin (Hematoxylin-Eosin and Giemsa stains), the dosage of mediators (serum tryptase level, serum histamine levels, urinary histamine metabolites) and the balance of expansion (complete blood cell count, liver biological investigations, abdominal ultrasound, skeletal radiography, chest radiography). For the adult with mastocytosis, we performed abdominal scanner and cytological study of the bone marrow. Following investigations carried out in each case, we mentioned the diagnosis of cutaneous mastocytosis, and also excluded several diseases confounded by clinically and histologically aspect. Considering the fact that the balance expansion was negative, we excluded the diagnosis of systemic mastocytosis. The presence of anemia and protein energetic malnutrition in children with mastocytosis involves carrying out balance extension for the exclusion of a systemic form of the disease. Histopathological examination of the skin using special stains, the dosage of mediators (serum tryptase level, serum histamine levels, urinary histamine metabolites) and balance expansion establish the diagnosis of cutaneous mastocytosis and also exclude many confusions because of the clinical presentation.

Unilateral telangiectasia macularis eruptiva perstans of the breast

We report a case of a 22-year-old female with an asymptomatic telangiectatic rash involving her left breast of 10 years' duration. Biopsies revealed cularis findings consistent with telangiectasia m a eruptiva perstans (TMEP). Telangiectasia macularis eruptiva perstans most often presents in a symmetric fashion; our patient represents an unusual case of unilateral TMEP involving the breast. Therefore, TMEP should be considered when a patient presents with telangiectasia, even if the presentation is unilateral.

[Bullous mastocytosis in infancy: a rare presentation]

Mastocytosis is a rare condition related to an abnormal proliferation of mast cells and their accumulation in tissues. Cutaneous mastocytosis is the most common form and mainly affects newborns and infants. The symptoms are caused by the release of mediators contained in mast cells, including histamine. Mastocytosis may be associated with a mutation in the gene encoding the c-kit receptor. Clinically, there are different dermatological findings, which combine acute cutaneous, digestive, or even hemodynamic manifestations in varying degrees. The diagnosis is confirmed by the histological study of a skin sample. We report here the case of a 4-month-old infant suffering from diffuse cutaneous bullous mastocytosis, a very rare variety of mastocytosis. This infant had an erosive and bullous manifestation of dermatosis, initially confused with impetigo. The proliferation of bullous lesions led to her hospitalization. Codeine intake for pain was responsible for a large and extensive bullous reaction associated with anaphylactic shock. This context of bullous spread occurring after taking codeine led to the suspicion of bullous diffuse cutaneous mastocytosis, a diagnosis that was confirmed histologically. This observation demonstrates the difficulty of mastocytosis diagnosis, mostly due to its rarity, especially in its diffuse bullous forms. The rapid deterioration of this patient, after the codeine prescription, emphasizes the importance of the eviction of histamine-releaser compounds in the management of this disease.

Letter: Cutaneous mastocytosis with systemic involvement mimicking clinical and dermatoscopically multiple melanocytic nevi

Mastocytosis can sometimes resemble other skin conditions, especially pigmented ones, not only clinically but also dermatoscopically. We report the case of a woman with the diagnosis of cutaneous mastocytosis mimicking multiple melanocytic nevi. Melanocytic stimulation can be induced by high levels of stem cell factor. The progressive increase in the number of pigmented lesions in a patient should lead us to perform a biopsy to search for mastocytosis.

Telangiectasia macularis eruptiva perstans

We present a 31-year-old woman with a ten-year history of a progressive macular eruption; one of her macules demonstrated a wheal when rubbed. A biopsy was consistent with telangiectasia macularis eruptiva perstans. There were no signs and symptoms of systemic involvement despite the large body surface area of involvement.

Diagnosis and treatment of cutaneous mastocytosis in children: practical recommendations

Cutaneous mastocytosis in children is a generally benign disease that can present at birth and is often associated with mast cell mediator-related symptoms including pruritus, flushing, and abdominal pain with diarrhea. The most common form of presentation is urticaria pigmentosa, also referred to as maculopapular mastocytosis. Flares of lesions are induced by triggers such as physical stimuli, changes in temperature, anxiety, medications, and exercise. The skin lesions are typically present on the extremities. Symptoms respond to topical and systemic anti-mediator therapy including antihistamines and cromolyn sodium. Remission at puberty is seen in a majority of cases. Progression to systemic mastocytosis with involvement of extracutaneous organs is not common. The cause of cutaneous mastocytosis is unknown and familial cases are rare. Mutations of c-kit have been observed in the skin of those affected. The diagnosis is established on clinical grounds and the findings on skin biopsy. Bone marrow studies are recommended if there is suspicion of progression of disease to an adult form, if cytoreductive therapy is contemplated, or if skin lesions remain present and/or tryptase levels remain elevated after puberty. The use of chemotherapy, including kinase inhibitors, is strongly discouraged unless severe hematologic disease is present, since malignant evolution is extremely rare.

Neonatal cutaneous mastocytosis

Neonatal cutaneous mastocytosis is rare infiltrative disorder of the skin. Though often asymptomatic, systemic features may be associated with any clinical pattern of the disorder at any age group. We present our experience with a 3 1/2 months old female child. She presented with recurrent eruption of tense bullae preceded by flushing, irritability since day 3 of life. Darier sign and dermatographism were present. Skin biopsy confirmed the case as urticaria pigmentosa which is the most common form of cutaneous mastocytosis. Investigation revealed deranged liver function. Child was given H1 antihistaminics and topical glucocorticoid. Family counselled about chance of anaphylaxis to various toxins and drugs and risk of development of systemic mastocytosis.

Diffuse cutaneous mastocytosis: report of a severe case with fatal outcome

Diffuse cutaneous mastocytosis (DCM) is a rare variant of mastocytosis. We describe a case of DCM with a very severe presentation at birth and fatal outcome.

Cutaneous mastocytosis: Two pediatric cases treated with topical pimecrolimus

Cutaneous mastocytosis is characterized by increased numbers of skin mast cells that release mediators causing pruritus, urticaria, and flushing. Most pediatric mastocytosis patients exhibit the pattern of urticaria pigmentosa, which typically appears during the first two years of life and resolves spontaneously in late adolescence. However, while the disease is active, patients are frequently symptomatic and uncomfortable, which justifies symptomatic treatment. We report 2 patients, a 14-month-old girl and a 26-month-old boy, with localized cutaneous erythematous lesions with a positive Darier sign. In each, a punch biopsy confirmed the diagnosis of mastocytosis. Treatment was instituted with pimecrolimus cream twice a day and oral antihistamine. An almost complete response was achieved after 4 months of therapy in both patients, with no clinical evidence of recurrence after 4 years and 2 years of follow-up, respectively. In children, the treatment of mastocytosis is directed primarily to avoiding potential mast cell degranulating agents and alleviating symptoms. Topical calcineurin inhibitors act by inhibiting T-cell activation and cytokine release; they may suppress mast cell- mediated reactions by reducing their degranulation. These two cases suggest that in localized cutaneous mastocytosis they are a safe and efficacious alternative to topical steroid therapy.

Most common clinical presentations of cutaneous mastocytosis

The term mastocytosis is referred to as an array of uncommon, usually sporadic, heterogeneous clinical illnesses that result from the hyperplasia of tissue mast cells. It comprises many different clinical manifestations varying from indolent cutaneous forms to systemic and malignant conditions. The characteristic presentation of mastocytosis consists of cutaneous manifestations: either a solitary mastocytoma, urticaria pigmentosa, or less commonly, diffuse cutaneous mastocytosis. Urticaria pigmentosa is the most common manifestation of cutaneous mastocytosis that manifests as a generalized eruption of round or oval erythematous macules, papules and plaques with variable amounts of brown pigment, usually on the trunk, but may also occur in all regions of the body including face and mucous membranes. Pruritus, dermographism and Darier's sign are additional features of these eruptions. Mastocytosis may also be manifested as mastocytoma, a rare, benign, pediatric tumor that results from hyperplasia of mast cells in papillary dermis in the first few weeks of life. The clinical course of mastocytosis is variable. The prognosis for the majority of pediatric patients with urticaria pigmentosa is extremely good, and over half of cases clear completely by adolescence, while those with aggressive systemic mastocytosis or mast cell leukemia show a progressive course, usually with a fatal outcome.

Type Ib indolent mastocytosis with systemic involvement: cutaneous mastocytosis and gastrointestinal involvement at young girl

A 21-year-old young girl presents with intense abdominal pain, nausea, diarrhea in the context of a cutaneous eruption formed by erythematous and papulous elements with brown violet aspect, very pruriginous, occasioned by the preparation of some fishmeal. Similar eruption debuted from childhood from the age of 4 year became rare with age. Since 3 years, the patient presents more intense digestive manifestation. The therapy with H2 antagonist (loratadine) and a mast cell stabilizer is beneficial over the digestive symptoms and in the same time cancel the pruritus and the erythema of the cutaneous lesions that remain hyperpigmented. The histopathological examination of a cutaneous lesion confirms the diagnosis of mastocytosis and the endoscopic examination discovers a duodenal ulcer and an erosive gastritis. The systemic mastocytosis is a rare disease, often associated with an urticaria pigmentosa, with difficult diagnosis in his absence. That's why, in patients with macular or nodular pigmented cutaneous lesions appeared in infancy and early childhood and which urticate in a characteristic manner when the skin is firmly rubbed, a cutaneous biopsy is necessary.

Mastocytosis: state of the art

Mastocytosis is a neoplastic disease involving mast cells (MC) and their CD34+ progenitors. Symptoms in mastocytosis are caused by biological mediators released from MC and/or the infiltration of neoplastic MC in various organs, the skin and the bone marrow being predominantly involved. A WHO consensus classification for mastocytosis exists, which is widely accepted and includes three major categories: (1) Cutaneous mastocytosis (CM), a benign disease in which MC infiltration is confined to the skin, is preferentially seen in young children and exhibits a marked tendency to regress spontaneously. (2) Systemic mastocytosis (SM) which is commonly diagnosed in adults and includes four major subtypes: (i) indolent SM (ISM, the most common form involving mainly skin and bone marrow); (ii) a unique subcategory termed SM with an associated non-mast cell clonal hematological disease (SM-AHNMD); (iii) aggressive SM usually presenting without skin lesions, and (iv) MC leukemia, probably representing the rarest variant of human leukemias. (3) The extremely rare localized extracutaneous MC neoplasms, either presenting as malignancy (MC sarcoma) or as benign tumor termed extracutaneous mastocytoma. Diagnostic criteria for mastocytosis are available and are widely accepted. SM criteria include one major criterion (multifocal compact tissue infiltration by MC) and four minor criteria: (1) prominent spindling of MC; (2) atypical immunophenotype of MC with coexpression of CD2 and/or CD25 (antigens which have not been found to be expressed on normal/reactive MC); (3) activating (somatic) point mutations of the c-kit proto-oncogene usually involving exon 17, with the imatinib-resistant type D816V being most frequent, and (4) persistently elevated serum tryptase level (>20 ng/ml). To establish the diagnosis of SM, at least one major and one minor criterion, or at least three minor criteria, have to be fulfilled. The natural clinical course of mastocytosis is variable. Most patients, in particular those with CM and ISM, remain in an indolent stage over many years or even decades, while others, in particular those with aggressive SM, SM-AHNMD, or mast cell leukemia, show a progressive course, usually with a fatal outcome.

Anetodermic mastocytosis: response to PUVA therapy

Mastocytosis is a group of disorders characterized by the accumulation of mast cells in different tissues and organs. The skin is the most frequently involved organ (90% of cases) where mastocytosis may show a heterogenic clinical expression. Anetodermic lesions are an unusual clinical presentation of mastocytosis. We report a case of anetodermic mastocytosis in a 26-year-old man, with sparse lesions and a benign course. PUVA therapy obtained excellent results in this case. Darier's sign should be investigated in patients with anetodermic lesions of unclear origin in order to exclude cutaneous mastocytosis.