A case of bullous pemphigoid in infancy treated with local corticosteroids.

Bullous pemphigoid (BP) is an immune-mediated subepidermal vesiculobullous eruption, whose true incidence is unknown, but it is considered extremely rare in children, with a usually indolent course and rare relapses. Diagnosis is often belated, because of the invasive assessment with biopsy for typical immune-pathologic findings to differentiate it from Dermatitis Herpetiformis and Linear IgA bullous dermatosis (LABD), more common in children. A 4-year-old girl presented with one year history of erythematous-edematous and erythematous-bullous eruptions on the genitalia, periocular regions, dorsal and palmo-plantar surfaces. At onset erosions of the month and lips where considered a primary herpes simplex infection from the pediatrician, but repeated courses of systemic antivirals were completely ineffective, while application of a antibiotic-steroidal cream was of partial benefit. Histopathology showed a dermo-epidermal blistering, with a marked eosinophilic infiltrate. Direct immunofluorescence showed a characteristic positive linear IgG and C3 band at the basement membrane zone (BMZ). Complete hematic-chemical and instrumental examinations gave normal results, excluding associated pathologies. Due to paucity of lesions and good response to local treatment with moderate potency cortisones, in agreement with the parents, no systemic therapy was started. No recurrence occurred in the 2 year follow-up after complete remission. The case is reported for the rarity of the childhood form, and the importance of the differential diagnosis for management and treatment. Good response to topical treatment is stressed, avoiding the risks of long-term systemic drug administration.

Immunoreactivity for alpha-smooth muscle actin characterizes a potentially aggressive subgroup of little basal cell carcinomas.

Basal cell carcinoma (BCC) is a very common malignant skin tumor that rarely metastatizes, but is often locally aggressive. Several factors, like large size (more than 3 cm), exposure to ultraviolet rays, histological variants, level of infiltration and perineural or perivascular invasion, are associated with a more aggressive clinical course. These morphological features seem to be more determinant in mideface localized BCC, which frequently show a significantly higher recurrence rate. An immunohistochemical profile, characterized by reactivity of tumor cells for p53, Ki67 and alpha-SMA has been associated with a more aggressive behaviour in large BCCs. The aim of this study was to verify if also little (<3 cm) basal cell carcinomas can express immunohistochemical markers typical for an aggressive behaviour.

Immunoreactivity for alpha-smooth muscle actin characterizes a potentially aggressive subgroup of little basal cell carcinomas.

Basal cell carcinoma (BCC) is a very common malignant skin tumor that rarely metastatizes, but is often locally aggressive. Several factors, like large size (more than 3 cm), exposure to ultraviolet rays, histological variants, level of infiltration and perineural or perivascular invasion, are associated with a more aggressive clinical course. These morphological features seem to be more determinant in mideface localized BCC, which frequently show a significantly higher recurrence rate. An immunohistochemical profile, characterized by reactivity of tumor cells for p53, Ki67 and alpha-SMA has been associated with a more aggressive behaviour in large BCCs. The aim of this study was to verify if also little (<3 cm) basal cell carcinomas can express immunohistochemical markers typical for an aggressive behaviour.

Merkel cell carcinoma with an unusual immunohistochemical profile.

The clinical and morphological picture of Merkel cell carcinoma (MCC) may be rather challenging; therefore, the immunohistochemical profile plays a relevant role in confirming the microscopic diagnosis. A panel of antibodies including cytokeratins 20, 7 and epithelial membrane antigen, and neuron-specific enolase is used in confirming the morphological diagnosis of MCC. The majority of MCCs express CK20 and are CK7-negative. Herein, we present a case of primary cutaneous neuroendocrine carcinoma with an atypical immunohistochemical pattern. A 83-years old woman presented with a painless plaque, red to violaceous in colour, located in the leg. The skin tumor was excided, formalin-fixed and paraffinembedded. Tissue sections were immunostained with a panel of antibodies routinely utilized in complex primary skin tumors for evidencing epithelial and neuroendocrine differentiation of tumor cells. The neuroendocrine differentiation of tumor cells was evidenced by their immunoreactivity for synaptophysin, chromograninA and neuron-specific enolase. Tumor cells also showed diffuse cytoplasmic staining for CK7. No immunoreactivity was detected for CK20 and thyroid transcription factor-1. Our data, together with previous rare reports of CK20-/CK7+ MCCs, lay stress on the importance of routinely utilizing a panel of antibodies in the differential diagnosis of complex primary carcinomas of the skin and may have important implications in expanding the differential diagnosis of skin tumors. In particular, caution should be taken in excluding the diagnosis of MCC only on the basis of the absence of reactivity of tumor cells for CK20, favouring the wrong diagnosis of less aggressive skin tumors.