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

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

Case report of sudden death after a gunshot wound to the C2 vertebral bone without direct spinal cord injury: Histopathological analysis of spinal-medullary junction

Gunshot wounds (GSW) are one of the most common causes of penetrating spinal injury, however few data are available regarding GSW causing an indirect fatal nervous tissue injury, such as that induced by the concussive force secondary to the bullet penetration. This report describes a rare case of a death following a GSW spine injury at the level of C2 vertebral body, without direct contact with the spinal cord, as seen with computed tomography scan performed soon after the death. At autopsy, vertebral canal and dura mater, as well as spinal cord and medulla oblongata, appeared devoid of pathologies and/or lesions, major viscera were unaltered. The cause of death was attributed to a cardiorespiratory arrest subsequent to the GSW injury of the C2 vertebral bone. Histopathological analysis of spinal cord and medulla oblongata was performed by means of conventional stainings, and glial fibrillary acidic protein (GFAP) and Neurofilaments 200 kD (NF) immunohistochemistry. Histological alterations stood out against a tissue with no other evident sign of neuropathology, and could be observed from the caudalmost part of the medulla oblongata to the level of the inferior olivary nucleus. Main structural changes were found in the white matter, involving often the adjacent gray matter, where they appeared as multiple scattered areas of degeneration, lacking the usual staining affinity, and showing a disrupted fibrillary pattern as evidenced by myelin staining, and GFAP- and NF-immunolabelling. The shock wave secondary to the impact on the C2 vertebral bone is likely to have been the cause of a widespread neuronal-axonal histopathological damage at the spinal-medullary junction and caudal medulla oblongata that is compatible with a severe fatal respiratory dysfunction and dysregulation of the autonomic pathways subserving the control of blood pressure and cardiac activity

Merkel cell carcinoma with an unusual immunohistochemical profile

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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 tumor

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

BK-virus progressive multifocal leukoencephalitis in a patient with systemic lupus erythematosus

Progressive multifocal leukoencephalopathy (PML) is a severe demyelinating disease of the central nervous system (CNS), fatal in some cases, and JC virus (JCV) is the usual cause. BK virus (BKV) is a ubiquitous virus and its primary infection is generally asymptomatic. It occurs in childhood [2] and, as well as JCV, belongs to the Polyomaviridae family. Both viruses are associated with a clinical disease in the setting of immunosuppression: JCV commonly in association with PML, while BKV with nephropathy and hemorrhagic cystitis [2]. Here we report a rare case of BKV-associated PML in a patient with systemic lupus erythematosus (SLE)