Development of Pityriasis Amiantacea after Valproic Acid Therapy.

Here, we present the case of a 16-year-old male who developed pityriasis amiantacea (PA) after the use of valproic acid. We propose that the keratinocyte proliferative activity of valproic acid mediated through the inhibition of glycogen synthase kinase-3β, and subsequent activation of the Wnt/β-catenin pathway could play a role in the development of PA. We additionally review the most relevant characteristics of this disease.

Granulomatous and lichenoid dermatitis after IgG4 anti-PD-1 monoclonal antibody therapy for advanced cancer.

Nivolumab is a fully human IgG4 monoclonal antibody directed against programmed cell death protein 1 (PD-1). PD-1 inhibition allows T-cell activation and recruitment to destroy cancer cells. Checkpoint inhibitors have shown significant survival advantage and relatively low side-effects in comparison with conventional chemotherapy in several types of advanced cancer.

Expression of MiTF may be helpful in differentiating cellular neurothekeoma from plexiform fibrohistiocytic tumor (histiocytoid predominant) in a partial biopsy specimen.

Background: Overlapping histopathologic features of cellular neurothekeoma (CNT) and plexiform fibrohistiocytic tumor (PFHT), when both are predominantly composed of histiocytoid cells, make distinction between these entities challenging. Some have suggested that CNT and PFHT are related entities. No prior study has demonstrated a reliable immunohistochemical panel to differentiate these entities.

Ataxia and cranial neuropathies from subcutaneously injected elemental mercury.

CONTEXT. Although neurological toxicity from elemental mercury vapor and organic mercury exposure has been commonly reported in the literature, it is rarely reported from soft tissue injection of elemental mercury. We present a case of neurological dysfunction from subcutaneous injection of elemental mercury.

Cellular neurothekeoma with fascicular growth features mimicking cellular dermatofibroma.

Background: Cellular neurothekeoma (CNT) is a benign cutaneous mesenchymal neoplasm. Most demonstrate a lobulated to micronodular architecture. Rarely, CNT demonstrates a predominantly fascicular growth pattern, without prominent sclerosis and thus can mimic cellular dermatofibroma (DF).

Cystic fibrosis transmembrane conductance regulator is helpful in the distinction of extra-mammary Paget's disease from squamous cell carcinoma in situ (Bowen's disease).

Cystic fibrosis transmembrane conductance regulator (CFTR) represents a cAMP-dependent channel found in normal apocrine glands. The classification and histogenesis of extra-mammary Paget's disease (EMPD) remains controversial, but it is generally accepted that primary EMPD exhibits apocrine differentiation. Therefore, we examined the utility of CFTR in the differential diagnosis of EMPD and squamous cell carcinoma in situ (SCCIS).

Extra-acral cutaneous/soft tissue sclerosing perineurioma: an under-recognized entity in the differential of CD34-positive cutaneous neoplasms.

Background: Perineuriomas are an uncommon group of tumors composed of perineurial cells of peripheral nerve sheath lineage. Variants include soft tissue (extraneural), intraneural, sclerosing, reticular and plexiform forms. Sclerosing perineuriomas have been reported to occur almost exclusively on the hands of young men.

Epithelioid hemangioma (angiolymphoid hyperplasia with eosinophilia) arising on the extremities.

Background: Epithelioid hemangioma (EH) is a benign vascular proliferation usually accompanied by a mixed inflammatory infiltrate.

Methods: Skin biopsy specimens from four patients with EH on the extremities were studied. Architecture, extent of vascular proliferation and the presence of epithelioid endothelial cells were evaluated.

Cyclooxygenase-2 expression during immortalization and breast cancer progression.

Identification of molecular aberrations in premalignant human mammary epithelial cells (hMEC), the precursors for breast cancers, is a central goal in breast cancer biology. Recent studies implicated expression of cyclooxygenase 2 (COX-2) as a marker to identify precursor cells for breast cancer. In this study, we analyzed COX-2 expression in preselection and postselection hMEC cells and observed similar COX-2 levels in both cells.

Histopathologic changes of porcine dermis xenografts for transvaginal suburethral slings.

Objective: The purpose of this study was to examine the histopathologic changes of HMDI (Hexamethylene di-isocyanate) cross-linked porcine dermis grafts used for suburethral sling surgery.

Study Design: Twelve patients underwent reoperation with graft removal for urinary retention or recurrent stress urinary incontinence after transvaginal sling surgery. Tissue specimens were available for pathologic evaluation in 7 patients.

The transcriptional repressor SNAIL is overexpressed in human colon cancer.

Overexpression of the transcriptional repressor, SNAIL, has been implicated in the pathogenesis of a number of malignancies; however, there are no previous reports on the role of SNAIL in colorectal cancers (CRCs). We, therefore, evaluated human CRC specimens for the presence of the SNAIL protein. Immunohistochemical studies were performed using samples obtained from archived CRC paraffin blocks and a tissue array.