J. Andrew Carlson

Overexpression of the MicroRNA hsa-miR-200c Leads to Reduced Expression of Transcription Factor 8 and Increased Expression of E-Cadherin

MicroRNAs are approximately 22-nucleotide sequences thought to interact with multiple mRNAs resulting in either translational repression or degradation. We previously reported that several microRNAs had variable expression in mammalian cell lines, and we examined one, miR-200c, in more detail. A combination of bioinformatics and quantitative reverse transcription-PCR was used to identify potential targets and revealed that the zinc finger transcription factor transcription factor 8 (TCF8; also termed ZEB1, deltaEF1, Nil-2-alpha) had inversely proportional expression levels to miR-200c. Knockout experiments using anti-microRNA oligonucleotides increased TCF8 levels but with nonspecific effects. Therefore, to investigate target predictions, we overexpressed miR-200c in select cells lines. Ordinarily, the expression level of miR-200c in non-small-cell lung cancer A549 cells is low in contrast to normal human bronchial epithelial cells. Stable overexpression of miR-200c in A549 cells results in a loss of TCF8, an increase in expression of its regulatory target, E-cadherin, and altered cell morphology. In MCF7 (estrogen receptor-positive breast cancer) cells, there is endogenous expression of miR-200c and E-cadherin but TCF8 is absent. Conversely, MDA-MB-231 (estrogen receptor-negative) cells lack detectable miR-200c and E-cadherin (the latter reportedly due to promoter region methylation) but express TCF8. The ectopic expression of miR-200c in this cell line also reduced levels of TCF8, restored E-cadherin expression, and altered cell morphology. Because the down-regulation of E-cadherin is a crucial event in epithelial-to-mesenchymal transition, loss of miR-200c expression could play a significant role in the initiation of an invasive phenotype, and, equally, miR-200c overexpression holds potential for its reversal.

Desmoplastic neurotropic melanoma. A clinicopathologic analysis of 28 cases

Background. Desmoplastic neurotropic melanoma (DNM) is a rare variant of malignant melanoma, the natural history and histogenesis of which still are being defined.

Clinical Approach to Cutaneous Vasculitis

Vasculitis is an inflammatory process affecting the vessel wall and leading to its compromise or destruction and subsequent hemorrhagic and ischemic events. Vasculitis can be classified as a primary phenomenon (e.g. idiopathic cutaneous leukocytoclastic angiitis or Wegener granulomatosis) or as a secondary disorder (connective tissue disease [CTD], infection, or adverse drug eruption-associated vasculitis). Cutaneous vasculitis may present as a significant component of many systemic vasculitic syndromes such as rheumatoid vasculitis or anti-neutrophil cytoplasmic antibody (ANCA)-associated primary vasculitic syndromes (Wegener granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis). Cutaneous vasculitis manifests most frequently as palpable purpura or infiltrated erythema indicating dermal superficial, small-vessel vasculitis, and less commonly as nodular erythema, livedo racemosa, deep ulcers, or digital gangrene implicating deep dermal or subcutaneous, muscular-vessel vasculitis. A biopsy extending to the subcutis taken from the most tender, reddish or purpuric lesional skin is the key to obtaining a significant diagnostic result and serial sections are often required for identifying the main vasculitic lesion. Coexistence of pan-dermal small-vessel vasculitis and subcutaneous muscular-vessel vasculitis usually indicates CTD, ANCA-associated vasculitis, Behçet disease, or malignancy-associated vasculitis. A concomitant biopsy for direct immunofluoresence evaluation contributes to accurate diagnosis by distinguishing IgA-associated vasculitis (Henoch-Schönlein purpura) from IgG-/IgM-associated vasculitis, which has prognostic significance. Treatment for cutaneous vasculitis should include avoidance of triggers (excessive standing, infection, drugs) and exclusion of vasculitis-like syndromes (pseudovasculitis) such as thrombotic disorders (e.g. anti-phospholipid antibody syndrome). In most instances, cutaneous vasculitis represents a self-limited condition and will be relieved by leg elevation, avoidance of standing, and therapy with NSAIDs. For mild recurrent or persistent disease, colchicine and dapsone are first-choice agents. Severe cutaneous disease requires treatment with systemic corticosteroids or more potent immunosuppression (azathioprine, methotrexate, cyclophosphamide). A combination of corticosteroids and cyclophosphamide is required therapy for systemic vasculitis, which is associated with a high risk of permanent organ damage or death. In cases of refractory vasculitis, plasmapheresis and intravenous immunoglobulin are viable considerations. The new biologic therapies that act via cytokine blockade or lymphocyte depletion, such as the tumor necrosis factor-α inhibitor infliximab and the anti-B-cell antibody rituximab, respectively, are showing benefit in certain settings such as CTD and ANCA-associated vasculitis.

Cutaneous vasculitis update: diagnostic criteria, classification, epidemiology, etiology, pathogenesis, evaluation and prognosis.

Vasculitis, inflammation of the vessel wall, can result in mural destruction with hemorrhage, aneurysm formation, and infarction, or intimal-medial hyperplasia and subsequent stenosis leading to tissue ischemia. The skin, in part due to its large vascular bed, exposure to cold temperatures, and frequent presence of stasis, is involved in many distinct as well as un-named vasculitic syndromes that vary from localized and self-limited to generalized and life-threatening with multi-organ disease. To exclude mimics of vasculitis, diagnosis of cutaneous vasculitis requires biopsy confirmation where its acute signs (fibrinoid necrosis), chronic signs (endarteritis obliterans), or past signs (acellular scar of healed arteritis) must be recognized and presence of extravascular findings such as patterned fibrosis or collagenolytic granulomas noted. Although vasculitis can be classified by etiology, many cases have no identifiable cause, and a single etiologic agent can elicit several distinct clinicopathologic expressions of vasculitis. Therefore, the classification of cutaneous vasculitis is best approached morphologically by determining vessel size and principal inflammatory response. These histologic patterns roughly correlate with pathogenic mechanisms that, when coupled with direct immunofluorescent examination, anti-neutrophil cytoplasmic antibody (ANCA) status, and findings from work-up for systemic disease, allow for specific diagnosis, and ultimately, more effective therapy. Herein, we review cutaneous vasculitis focusing on diagnostic criteria, classification, epidemiology, etiology, pathogenesis, and evaluation of the cutaneous vasculitis patient.

The histological assessment of cutaneous vasculitis

Carlson J A
(2010) Histopathology56, 3–23
The histological assessment of cutaneous vasculitis

Mucinous Carcinoma of the Skin, Primary, and Secondary A Clinicopathologic Study of 63 Cases With Emphasis on the Morphologic Spectrum of Primary Cutaneous Forms: Homologies With Mucinous Lesions in the Breast

We present the largest series of mucinous carcinoma involving the skin, describing the histopathologic, immunohistochemical, electron microscopic, and cytogenetic findings. Our aim was fully to characterize the clinicopathologic spectrum and compare it with that seen in the breast. In addition, we wished to reevaluate the differential diagnostic criteria for distinguishing primary mucinous carcinomas from histologically similar neoplasms involving the skin secondarily, and study some aspects of their pathogenesis. We demonstrate that primary cutaneous mucinous carcinomas span a morphologic spectrum compatible to their mammary counterparts. Both pure and mixed types can be delineated morphologically, and some lesions have mucocele-like configurations. Most lesions seem to originate from in situ lesions that may represent, using mammary pathology terminology, ductal hyperplasia, atypical ductal hyperplasia, or ductal carcinoma in situ or a combination of the three. Inverse cell polarity appears to facilitate the progression of the changes similar to lesions in the breast. The presence of an in situ component defines the neoplasm as primary cutaneous, but its absence does not exclude the diagnosis; although for such neoplasms, full clinical assessment is essential. Mammary mucinous carcinoma involving the skin: all patients presented with lesions on chest wall, breast, axilla, and these locations can serve as clue to the breast origin. Microscopically, cutaneous lesions were of both pure and mixed type, and this correlated with the primary in the breast. Dirty necrosis was a constant histologic finding in intestine mucinous carcinomas involving the skin, and this feature may serve as a clue to an intestinal origin.

Current concepts of metastasis in melanoma

The main cause of death in melanoma patients is widespread metastases. Staging of melanoma is based on the primary tumor thickness, ulceration, lymph node and distant metastases. Metastases develop in regional lymph nodes, as satellite or in-transit lesions, or in distant organs. Lymph flow and chemotaxis is responsible for the homing of melanoma cells to different sites. Standard pathologic evaluation of sentinel lymph nodes fails to find occult melanoma in a significant proportion of cases. Detection of small numbers of malignant melanoma cells in these and other sites, such as adjacent to the primary site, bone marrow or the systemic circulation, may be enhanced by immunohistochemistry, reverse transcription PCR, evaluation of lymphatic vessel invasion and proteomics. In the organs to which melanoma cells metastasize, extravasation of melanoma cells is regulated by adhesion molecules, matrix metalloproteases, chemokines and growth factors. Melanoma cells may travel along external vessel lattices. After settling in the metastatic sites, melanoma cells develop mechanisms that protect them against the attack of the immune system. It is thought that one of the reasons why melanoma cells are especially resistant to killing is the fact that melanocytes (cells from which melanoma cells derive) are resistant to such noxious factors as ultraviolet light and reactive oxygen species. Targeted melanoma therapies are, so far, largely unsuccessful, and new ones, such as adjuvant inhibition of melanogenesis, are under development.

Cellular blue nevus with atypia (atypical cellular blue nevus): a clinicopathologic study of nine cases

Atypical cellular blue nevus (ACBN) has clinicopathologic features intermediate between typical cellular blue nevus (CBN) and the rare malignant blue nevus (MBN)/malignant melanoma (MM) arising in a CBN. Herein we report 9 cases of ACBN. The patients were caucasian (6 females and 3 males) with a mean and median age of 47/51 years. Two patients complained of recent changes and about half of these tumors were located on the buttocks or scalp, averaging 1.5 cm in diameter. Histologically, they were characterized by architectural atypia (infiltrative margin and/or asymmetry) and/or cytologic atypia (hypercellularity, nuclear pleomorphism, hyperchromasia, mitotic figures, and/or necrosis). Assessment of the expression of 3 tissue markers demonstrated rare solitary cell staining with oncogene product bcl‐2, and a proliferative index of 23±19 and 39±30 cells/10 high power field with antibodies to PCNA and Mib‐1, respectively. No significant differences were detected comparing the above levels of expression to a control group of 15 CBN; however, ACBNs tended to show a higher proliferative index by PCNA and Mib‐1 as well as a significantly higher mitotic rate (1/10 HPF vs. 0; p=0.001). Analysis of DNA content showed DNA anetiploidy in both groups. Follow‐up data on 9 of 9 patients showed 1 patient dead without disease and 8 alive without disease (mean/median follow‐up 42/32 months, range 15‐96 months). No patient during this follow‐up time has experienced either a local recurrence or lymph node or visceral metastasis. These findings highlight the close resemblance of ACBN to the natural history of CBN. Nevertheless, many of the distinguishing histologic features of ACBN are also those of MBN. Because of these intermediate clinicopathologic features, ACBN warrant close scrutiny and long‐term follow‐up.

Actin-binding protein fascin expression in skin neoplasia

Background:  Fascin containing actin bundles provide mechanical support to cellular protrusions and stress fibers. In cancers, some malignant cells (e.g. subsets of breast and ovarian carcinomas) express fascin. In skin cancer, the role of fascin is unknown.

Melanogenesis affects overall and disease-free survival in patients with stage III and IV melanoma.

Because melanogenesis can affect immune responses to and chemotherapy and radiotherapy for melanoma, we analyzed overall survival and disease-free survival times in melanoma patients in relation to the degree of tumor pigmentation. Clinicopathologic data were obtained from the Oncology Centre, Prof Franciszek Łukaszczyk Memorial Hospital, Bydgoszcz, Poland. The overall survival and disease-free survival analyses were performed using the log-rank test, whereas differences between mean/median overall survival and disease-free survival (days) were analyzed using the Student t test. In patients with metastatic disease, those with melanotic melanomas exhibited significantly shorter disease-free survival and overall survival than those with amelanotic lesions. Similarly, melanin-producing lymph node metastases were linked to shorter overall survival and disease-free survival, which was confirmed by a significantly longer mean/median disease-free survival for amelanotic versus melanotic metastases. Melanogenesis shortens overall survival and disease-free survival in patients with metastatic melanoma. Inhibition of melanogenesis appears a rational adjuvant approach to the therapy of metastatic melanoma.