Aromatase may play a critical role in the pathogenesis of juvenile nasopharyngeal angiofibroma.

The pathophysiology of juvenile nasopharyngeal angiofibroma (JNA) has yet to be fully elucidated, but the influence of steroid hormones in their growth has been suggested. This neoplasm is known to afflict adolescent males. However, only a minority of the neoplastic cells express androgen receptors.

Expression of alpha-methylacyl-CoA racemase (P504S) in sebaceous neoplasms.

Background: Alpha-methylacyl-CoA racemase (AMACR), also known as P504S, is a protein that plays an important role in mitochondrial and peroxisomal beta-oxidation of branched-chain fatty acid and bile acid intermediates. AMACR has been established as a valuable diagnostic marker for prostate cancer and has recently been shown to be useful in the diagnosis of colorectal carcinoma. Despite the importance of lipid metabolism in sebum production by sebaceous glands of the skin, there are no studies evaluating the expression of AMACR in sebaceous neoplasms.

Potential utility of CD5 immunohistochemical staining in the diagnosis of muscle tumors.

CD5 is a 67 KD glycoprotein receptor that is present on a variety of T lymphocytes and mantle zone lymphocytes and is used routinely for the diagnosis of lymphomas and thymic carcinomas. That CD5 may be useful in diagnosis of mesenchymal tumors was an incidental finding in our sarcoma practice. This pilot study evaluated CD5 expression in benign and malignant muscle tumors in comparison to normal muscle.

Successful treatment of disseminated granuloma annulare with adalimumab.

A 61-year-old female with a 4-year history of disseminated granuloma annulare was successfully treated with the antitumor necrosis factor (TNF)-alpha antibody, adalimumab. The patient had failed high potency topical glucocorticoids, hydroxychloroquine, and narrow-band ultraviolet light (UV)-B phototherapy. Anti-TNF-alpha therapy may be a therapeutic option in patients with disseminated granuloma annulare poorly controlled with conventional medications.

Bif-1 and Bax expression in cutaneous Merkel cell carcinoma.

Background: Bax-interacting factor-1 (Bif-1) binds to Bax, which in turn activates this proapoptotic protein. In the absence of Bif-1, the ability to induce apoptosis through the intrinsic pathway is greatly reduced. Merkel cell carcinoma (MCC) classically shows an aggressive behavior and lack of response to chemotherapy, which remains unexplained.

Immunohistochemical expression of survivin in cutaneous sebaceous lesions.

Background: Survivin is a member of the inhibitor of apoptosis family of proteins implicated in the inhibition of apoptosis and cell cycle control, both crucial in the progression to malignancy. Survivin overexpression has been demonstrated in numerous malignancies including cutaneous squamous cell carcinoma and melanoma. To date, there are no studies evaluating the expression of survivin in sebaceous neoplasms.

Acetylcholine receptor expression in Merkel cell carcinoma.

Neurocrest-derived tissues express muscarinic and nicotinic acetylcholine receptors (mAChR and nAChR respectively). These receptors are critical for migration of neurocrest-derived cells to their corresponding tissues during development. Recent reports demonstrate neurocrest-derived melanoma and numerous non-Merkel cell neuroendocrine tumors express both muscarinic and nicotinic receptors.

Assessment of muscarinic and nicotinic acetylcholine receptor expression in primitive neuroectodermal tumor/ewing family of tumor and desmoplastic small round cell tumor: an immunohistochemical and Western blot study of tissue microarray and cell lines.

The primitive neuroectodermal tumor (PNET)/Ewing family of tumors (EFT) and desmoplastic small round cell tumor (DSRCT) portend a grave prognosis. Ongoing research in similar neurocrest-derived neoplasms has implicated both the muscarinic acetylcholine receptor (mAChR) and nicotinic acetylcholine receptor (nAChR) in the pathogenesis of these neoplasms. Acetylcholine has been reported to impart a modulatory effect on chemotaxis and proliferation, an effect ameliorated by anticholinergic drugs.

CD117 immunoreactivity in atypical fibroxanthoma.

Atypical fibroxanthoma (AFX) is a spindle cell neoplasm of the skin seen typically on sun-damaged skin of the elderly. Though described as a benign entity, local recurrence and distant metastasis have been reported. This study aims to investigate the potential pathogenic role of CD117, the c-kit receptor in AFX.

Cryptic "chromo-fibroma".

Chromoblastomycosis is an uncommon chronic fungal infection capable of presenting in a variety of clinical guises. Herein, we present the histopathological features of an unusual dermal response engendered by this organism, consisting of dermal effacement by a spindle cell proliferation arranged in sweeping fascicles.

HER2 and EGFR expression in cutaneous spindle squamous cell carcinoma.

Background: Epidermal growth factor receptor (EGFR) and HER2, members of the Erb family of transmembrane receptor tyrosine kinases (RTK), are responsible for communicating extracellular signals to the nucleus. Moreover, EGFR and HER2 are implicated in tumorgenesis. Immunohistochemical studies have demonstrated that approximately 80% of cutaneous squamous cell carcinomas (SCC) express EGFR.

Malignant perivascular epithelioid cell tumor ('PEComa'): a case report and literature review of cutaneous/subcutaneous presentations.

Perivascular epithelioid cell (PEC) tumors, also called 'PEComas,' are distinct tumors showing PEC differentiation with characteristic histologic and immunophenotypic features. PEComas are rare tumors documented in the literature presenting in numerous anatomic sites including the thorax, abdomen, pelvis, soft tissue and skin. Criteria for malignancy does not exist for the subset of PEComas that pursue an aggressive clinical course.

A case series and immunophenotypic analysis of CK20-/CK7+ primary neuroendocrine carcinoma of the skin.

Background: The diagnosis of Merkel cell carcinoma (MCC) can be rather challenging; therefore, the immunohistochemical profile is important in confirming the microscopic diagnosis. Characteristic of the neuroendocrine and epithelial differentiation of MCC, antibodies to cytokeratin (CK) 20, CK7, epithelial membrane antigen, and neuron-specific enolase among others, are used in confirming the diagnosis. As reported in the literature, the majority of MCC express CK20 and are CK7 negative.

Prednisolone inhibits LPS-induced bone marrow suppressor cell activity in vitro but not in vivo.

Glucocorticoids are used clinically to treat a variety of inflammatory diseases including endotoxemia. We hypothesized that injecting mice with the steroid prednisolone (pred) would mitigate the enhanced bone marrow (BM) natural suppressor (NS) cell activity that occurs in mice after receiving an injection of lipopolysaccharide (LPS). In vitro, prednisolone blocked the ability of NS cells to produce the immunosuppressive molecule nitric oxide (NO) and also the ability to suppress T cell proliferation.