Mastocitoma solitario: hallazgo en un examen de salud / Solitary mastocytoma: found in a health examination

Introducción. El mastocitoma solitario consiste en la infiltración localizada de mastocitos en la piel, y normalmente se manifiesta como una placa o mácula marronosa-anaranjada. Es una de las formas de mastocitosis más frecuente en la infancia, junto con la urticaria pigmentosa. El 55% de los casos de mastocitosis se presentan durante los 2 primeros años de vida. Observación clínica. Se presenta el caso de un niño de 18 meses que presenta una lesión de un centímetro de diámetro en región lumbar, asintomática, de meses de evolución. Al frotar la lesión, ésta se vuelve más eritematosa, y provoca molestias al paciente. Por estas características clínicas se diagnostica de mastocitoma solitario. Comentarios. El diagnóstico de mastocitoma solitario es principalmente clínico. En general no requiere tratamiento, ya que suele involucionar espontáneamente durante la edad infantil. Tan sólo en algunos casos, en los que la liberación de histamina provoca clínica sistémica, es necesario tratamiento antihistamínico(AU)

Introduction. Solitary mastocytoma consists of the localised leaking of mastocytes into the skin, and normally is manifested as a brownish- orange plaque or macule. It is one of the most frequent forms of mastocytosis in childhood, along with urticaria pigmentosa. 55% of the cases of mastocytosis appear during the first two years of life. Clinical observation. There is the case of an 18-month-old child who presents with a skin lesion that is one centimetre in diameter, in the lumbar region, asymptomatic, with some months of evolution. When the lesion is rubbed, it turns more erythematic, and bothers the patient. With these clinical characteristics, solitary mastocytoma is diagnosed. Comments. The diagnosis of solitary mastocytoma is mainly clinical. In general it doesn’t require treatment, as it normally resolves itself spontaneously during the childhood years. Only in some cases, when the secretion of histamine when the injury is rubbed causes systemic clinical symptoms, antihistaminic treatment must be established(AU)

Treponema pallidum distribution patterns in mucocutaneous lesions of primary and secondary syphilis: an immunohistochemical and ultrastructural study.

To study the different patterns of Treponema pallidum distribution in primary and secondary syphilis, 34 biopsy specimens of 8 patients with primary and 26 with secondary syphilis were assessed. Histopathological features, silver stain, and immunohistochemical T pallidum polyclonal antibody expression were investigated. The number and distribution of spirochetes were evaluated, and ultrastructural studies were performed. Spirochetes were identified with Warthin-Starry stain in 17 specimens (4/8 primary and 13/26 secondary syphilis), whereas immunohistochemical analysis disclosed spirochetes in 29 (8/8 primary and 21/26 secondary syphilis). In secondary syphilis, an epitheliotropic pattern characterized by abundant spirochetes in the lower mucosa/epidermis in an intercellular distribution was observed. In contrast, primary syphilis exhibited a mixed epitheliotropic and vasculotropic pattern further manifested by treponemes surrounding the vascular walls. These differences were statistically significant. Ultrastructural examination confirmed these results. Immunohistochemistry shows greater sensitivity when compared with Warthin-Starry staining. The immunohistochemical pattern of T pallidum distribution may permit the diagnostic differentiation of primary from secondary syphilis.

Aberrant nuclear BCL10 expression and lack of t(11;18)(q21;q21) in primary cutaneous marginal zone B-cell lymphoma.

Inhibition of apoptosis seems to play an important role in the pathogenesis of marginal zone lymphoma. Apoptosis regulator B-cell lymphoma 10 (BCL10) may show aberrant nuclear localization in some aggressive extracutaneous MALT lymphomas, often in association with a MALT1 gene t(11;18)(q21;q21) translocation. The possible occurrence of this association in primary cutaneous marginal zone lymphoma (PCMZL) remains insufficiently explored. The aim of this study was to evaluate BCL10 protein expression pattern and its possible relationship to the presence of t(11;18)(q21;q21) and other MALT1 gene abnormalities in PCMZL and to assess their clinical significance. The study included 42 consecutive PCMZL patients diagnosed on the basis of the World Health Organization/European Organization for the Research and Treatment of Cancer classification criteria. BCL10 expression was immunohistochemically evaluated in all cases, whereas t(11;18)(q21;q21) reverse transcriptase polymerase chain reaction amplification was performed on 21 samples. In addition, the presence of other MALT1 gene translocations was explored in 26 samples by interphase fluorescence in situ hybridization using a MALT1 locus-specific probe. We observed the presence of aberrant nuclear BCL10 expression in a significant number of PCMZL cases (36%, 15/42). This aberrant expression was significantly related to the development of extracutaneous disease. In contrast, neither the t(11;18)(q21;q21) translocation nor other MALT1 gene translocations could be demonstrated. t(11;18)(q21;q21), strongly linked to extracutaneous MALT lymphomas, does not seem to play a role in PCMZL. The participation of other MALT1 gene translocations in PCMZL pathogenesis seems also unlikely.

Annually recurring erythema annulare centrifugum: a distinct entity?

Four patients presenting a peculiar clinical variant of erythema annulare centrifugum are reported. The lesions were clinically and histopathologically indistinguishable from classic superficial erythema annulare centrifugum but constant annual and seasonal recurrences for many years or decades were observed. No clear precipitating factor could be identified. No associated symptoms were present and the eruption regressed spontaneously after a variable period of days to months. Annually recurring erythema annulare centrifugum seems to represent a rare distinct clinical entity that has received little attention in literature. Clinicopathologic features of this peculiar clinical disorder and the differential diagnosis with other recurrent seasonal eruptions are reviewed.

Large atypical melanocytic nevi in recessive dystrophic epidermolysis bullosa: clinicopathological, ultrastructural, and dermoscopic study.

A 3-year-old boy with recessive dystrophic epidermolysis bullosa developed a rapidly growing, large, acquired irregular melanocytic nevus on the lower aspect of the back. The lesion was clinically atypical and fulfilled the criteria for a malignant melanocytic proliferation. A complete surgical excision was performed. Histopathologic examination disclosed a compound melanocytic nevus without melanocytic atypia. Ultrastructural examination showed melanocytic cells located both at the roof and the floor of the blister. Several months later, three pigmentary lesions with a similar clinical appearance developed. Periodic clinical and dermoscopic examinations were recommended. Dermoscopic examination disclosed a globular pattern with brown globules and black dots distributed all over the lesions. The lesions also exhibited blue-greyish dots and multiple rounded white structures corresponding to milia-like cysts. No dermoscopic features suggestive of malignancy were noted. Acquired melanocytic nevi showing atypical clinical features have been reported to occur in areas of blistering in patients with epidermolysis bullosa. These nevi appear as large, asymmetrical pigmentary lesions with irregular borders. Initially, they are very dark in pigmentation, with color variegation and loss of pigment, and even becoming papillomatous over time. Histopathologic examination can show features of compound/junctional nevus as well as persistent/recurrent nevus. The concept of "epidermolysis bullosa nevus" has been proposed to define these peculiar lesions. The clinical, histopathologic and ultrastructural features of these nevi are reviewed. The usefulness of dermoscopic examination in the routine diagnosis and follow-up of these lesions are stressed.

Genetic characterization of the paraimmunoblastic variant of small lymphocytic lymphoma/chronic lymphocytic leukemia: A case report and review of the literature.

Paraimmunoblastic variant of small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) is characterized by a diffuse proliferation of cells, called paraimmunoblasts, normally located on the pseudoproliferation centers. Patients usually present with multiple lymphadenopathies and a rapid and aggressive progression of the disease. We report a case with paraimmunoblastic variant of SLL/CLL genetically well-characterized by conventional cytogenetics, comparative genomic hybridization (CGH), IgH/BCL-1, IgH/BCL-2, and p53 fluorescent in situ hybridization (FISH) probes and polymerase chain reaction (PCR) for detection of IgH/BCL-2 translocation. A complex karyotype was found, with p53 deletion confirmed by CGH and FISH; however, no translocations involving either BCL-2 or BCL-1 and the immunoglobulin heavy chain gene were identified. A literature review shows only 20 previously reported cases, 6 of which involve genetic studies.