Diagnostic application of cyclin D1 fluorescent in situ hybridization for histologically undetermined early lesions of acral melanoma in situ: A case series.

Histologically undetermined early acral melanoma in situ (HUAMIS) is rare but a diagnostic challenge, being clinically and dermoscopically MIS (late onset, a large size (>7 mm), parallel ridges pattern) but microscopically without recognizable cytological atypia. Cyclin D1 (CCND1) gene amplification is a genetic aberration occurring in the early radial growth phase of AMs and could thus help determine malignancy for this disease. We determine the value of CCND1 amplification by FISH as a diagnostic marker for HUAMIS. CCND1 amplification was examined in paraffin-embedded skin biopsies and excisions using a dual-probes fluorescence in situ hybridization (FISH) (11q13 and CEP11). One FISH-negative case 6 was additionally examined by Mypath Melanoma (qRT-PCR). Seventeen cases (12 dysplastic nevi, 3 AMIS, and 2 invasive AM) were served as negative controls for FISH. All six patients (4 females and 2 males) were Hispanic. Pigment lesions were on the left plantar foot (4), right third finger palm (1), and right thumb subungual (1). All cases showed similar clinical and dermoscopical characteristics, including late onset (50 to 74 years old), long duration (from 2 to 15 years), large-sized pigments (from 16 to 40 mm), and a parallel ridge pattern. Junctional melanocytes with no or minimal atypia from five cases showed CCND1 amplifications. Four of 5 cases were received 1st or/and 2nd wide excisions, which demonstrated foci of histologically overt MIS. One FISH-negative case 6 demonstrated "likely malignancy" scores (>2) by Mypath Melanoma (qRT-PCR). None of negative controls showed the amplification. We propose here a simple CCND1 FISH is a practical diagnostic test to determine the malignancy of the very early progression phase of AM preceding histopathologically defined MIS. Cases presented here could be an indolent subtype of AMIS characterized by carrying a long latent radial growth phase without vertical growth, mimicking lentigo maligna.

Primary cutaneous Rosai-Dorfman disease; a case-based review of a diagnostically and therapeutically challenging rare variant.

Primary cutaneous Rosai-Dorfman disease is a rare form of Rosai-Dorfman disease limited to the skin. The diagnosis of primary cutaneous disease is based on a combination of clinical presentation, histopathology, and the detection of S100+, CD68+, and CD1a- histiocytic immunophenotyping. However, the diagnosis of primary cutaneous disease is often difficult and significantly delayed due to the non-specific nature of its histologic and clinical features. In this review, we describe four cases in order to familiarize pathologists and dermatopathologists with the clinicopathologic correlation of primary cutaneous Rosai-Dorfman disease and to help facilitate early diagnosis. In addition, we discuss the proposed pathophysiology and molecular etiology of this tumor, and its relationship with IgG4 sclerosing disease.

Multifocal congenital pyogenic granuloma successfully treated with oral propranolol.

Disseminated congenital pyogenic granuloma (DCPG) is an uncommon condition. Individual lesions of DCPG share clinical and histologic similarities with infantile hemangioma (IH); endothelial glucose transporter 1 (GLUT-1), which is highly expressed in IH but generally not in pyogenic granulomas (PG), is an important diagnostic tool. Treatment for DCPG remains difficult. We describe a case of DCPG effectively treated with propranolol.

Adult T-cell leukemia/lymphoma can be indistinguishable from other more common T-cell lymphomas. The University of Miami experience with a large cohort of cases.

Adult T-cell leukemia/lymphoma, an aggressive T-cell neoplasm, is causally linked to human T-cell lymphotropic virus type 1 and based on this association has a distinct geographic distribution. In our United States-based practice, whose population is enriched for immigrants from human T-cell lymphotropic virus type 1 endemic areas, we have identified that a subset of adult T-cell leukemia/lymphoma, in the absence of human T-cell lymphotropic virus type 1 identification, are indistinguishable from other more common T-cell neoplasms. We retrospectively gathered serology results for anti-human T-cell lymphotropic virus type 1/2 antibody in patients diagnosed with T-cell neoplasms at our institution. A total of 220 human T-cell lymphotropic virus type 1/2 positive patients with T-cell neoplasms were identified; 199 (91%) were correctly classified as adult T-cell leukemia/lymphoma or provisionally as peripheral T-cell lymphoma (serology testing pending). Twenty-one cases (9%) were initially misclassified, including the following: 13 presenting with skin +/- peripheral blood involvement and misclassified as mycosis fungoides/Sezary syndrome; 7 with lymphomatous disease, absence of leukemic involvement, and diffuse CD30 expression, misclassified as ALK- negative anaplastic large-cell lymphoma; 1 thought to represent T-prolymphocytic leukemia with TCL-1 gene rearrangement and diffuse marrow involvement. We also present an example of adult T-cell leukemia/lymphoma, which mimicked lymphoepithelioid variant of peripheral T-cell lymphoma also with diffuse marrow involvement. A subset of adult T-cell leukemia/lymphoma can closely mimic a variety of other more common T-cell neoplasms. Due to its extreme clinicopathologic heterogeneity, identification of adult T-cell leukemia/lymphoma requires a high level of suspicion based on patient demographic alone, which should prompt anti-human T-cell lymphotropic virus type 1/2 serology testing in all T-cell neoplasms developing in patients of appropriate demographic. Absence of high level of suspicion, adult T-cell leukemia/lymphoma is easily misclassified.

Morbihan disease complicated by dermatosis neglecta: An unique presentation.

Morbihan disease, also referred to as solid facial edema, or rosacea lymphedema, is a rare disorder that involves chronic erythema and solid edema of the cheeks, eyelids, forehead and glabella and may arise as a complication of acne vulgaris or rosacea. Of note, it may be the only initial presenting symptom of these associated diseases. Few cases have been described in the literature, as its first description by Robert Degos in 1957. The condition is characterized by its chronicity, a typical clinical appearance and the lack of specific histopathologic or laboratory findings. The condition may wax and wane but typically does not resolve without treatment. Many cases of this condition tend to be recalcitrant to therapy, with topical and oral antibiotics regimens commonly used for rosacea generally being ineffective. The disease may easily go undiagnosed, as it mimics other more common skin conditions. We present a case of originally undiagnosed Morbihan disease mistaken for an atypical allergic rash, resistant to treatment, and complicated by dermatosis neglecta.

Giant proliferating trichilemmal cyst arising from a nevus sebaceus growing for 30 years.

Nevus sebaceus of Jadassohn, a congenital cutaneous hamartoma, has the potential to develop into various epidermal adnexal-origin neoplasms. While the most common neoplasms are trichoblastoma or syringocystadenoma, proliferating trichilemmal cysts are exceptionally rare. We report a case of a 63-year-old Cuban male with a giant proliferating trichilemmal cyst arising from a nevus sebaceus on the right shoulder which had been growing for 30 years. Proliferating trichilemmal cysts arising from nevus sebaceus cases are difficult to diagnose clinically and histologically as they are very rare and have not been defined by exact diagnostic criteria. Our case creates awareness of this particular tumor in nevus sebaceus and shares clinical and histological diagnostic information that can be used to make a proper diagnosis.

A diagnostic algorithm for atypical spitzoid tumors: guidelines for immunohistochemical and molecular assessment.

Atypical spitzoid tumors are a morphologically diverse group of rare melanocytic lesions most frequently seen in children and young adults. As atypical spitzoid tumors bear striking resemblance to Spitz nevus and spitzoid melanomas clinically and histopathologically, it is crucial to determine its malignant potential and predict its clinical behavior. To date, many researchers have attempted to differentiate atypical spitzoid tumors from unequivocal melanomas based on morphological, immonohistochemical, and molecular diagnostic differences. A diagnostic algorithm is proposed here to assess the malignant potential of atypical spitzoid tumors by using a combination of immunohistochemical and cytogenetic/molecular tests. Together with classical morphological evaluation, this algorithm includes a set of immunohistochemistry assays (p16(Ink4a), a dual-color Ki67/MART-1, and HMB45), fluorescence in situ hybridization (FISH) with five probes (6p25, 8q24, 11q13, CEN9, and 9p21), and an array-based comparative genomic hybridization. This review discusses details of the algorithm, the rationale of each test used in the algorithm, and utility of this algorithm in routine dermatopathology practice. This algorithmic approach will provide a comprehensive diagnostic tool that complements conventional histological criteria and will significantly contribute to improve the diagnosis and prediction of the clinical behavior of atypical spitzoid tumors.

Successful Treatment of Primary Cutaneous Mucormycosis Complicating Anti-TNF Therapy with a Combination of Surgical Debridement and Oral Posaconazole.

Lipid formulations of amphotericin B remain the first-line antifungal therapy for invasive mucormycosis. Posaconazole is an alternative for salvage therapy, but its use as primary therapy is not recommended due to the paucity of clinical data. Here we describe the case of a 57-year-old diabetic woman receiving etanercept and prednisone for the treatment of psoriatic arthritis who developed primary cutaneous mucormycosis after a minor gardening injury. Infection was successfully treated with aggressive surgical debridement followed by a 6-week course of the new delayed-release tablet formulation of posaconazole and temporary withholding of anti-TNF treatment. Primary antifungal therapy with posaconazole can be considered in selected cases of cutaneous mucormycosis.

Blastic plasmacytoid dendritic cell neoplasm: evolving insights in an aggressive hematopoietic malignancy with a predilection of skin involvement.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) derived from precursors of plasmacytoid dendritic cells is a very rare, unique, and highly aggressive immature hematopoietic malignancy, more frequently occurring among healthy elderly adults. BPDCN can be characterized by a striking predilection for cutaneous involvement, which is often detected incidentally by dermatologists and is difficult to clinically distinguish it from other primary skin lesions and histologically from leukemia/lymphoma cutis. Thus, histological diagnosis of cutaneous biopsies is crucial to correctly classify this entity. Most patients eventually progress to acute myeloid leukemia and are generally not curable. Here, we present 2 cases of classic BPDCN and discuss the origin of tumor and literature-based characteristic clinical and morphological features, evolving immunomarkers, and molecular genetic aspects of this neoplasm.

Side population of a murine mantle cell lymphoma model contains tumour-initiating cells responsible for lymphoma maintenance and dissemination.

'Cancer stem cells' or 'tumour initiating cells' in B-cell non-Hodgkin lymphomas have not been demonstrated, although some studies focused on other cancer types suggest that such populations exist and represent tumour cells resistant to therapy and involved in relapse. These cells may also represent a putative neoplastic 'cell of origin' in lymphomas, but there is little substantive data to support this suggestion. Using cell lines derived from a recently established murine IL-14alphax c-Myc double transgenic/mantle cell lymphoma-blastoid variant model, heretofore referred to as DTG cell lines, we identified a subset of cells within the side population (SP) with features of 'tumour-initiating cells'. These features include higher expression of ABCG2 and BCL-2, longer telomere length, greater self-renewal ability and higher in vitro clonogenic and in vivo tumorigenic capacities compared with non-SP. In addition, in vitro viability studies demonstrated that the non-SP lymphoma subpopulation has a limited lifespan in comparison with the SP fraction. Syngenic transplant studies showed that non-SP derived tumours, in comparison to the SP-derived tumours, exhibit greater necrosis/apoptosis and less systemic dissemination capability. In conclusion, our data support the interpretation that the DTG SP fraction contains a cell population highly capable of tumour maintenance and systemic dissemination and lends support to the concept that 'tumour-initiating cells' occur in lymphomas.

Early-stage mycosis fungoides variants: case-based review.

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma. The diagnosis of classic MF is based on a combination of clinical presentation, histopathology, and T-cell monoclonality detected by molecular studies. However, the diagnosis can be difficult in cases of early MF because of the subtle nature of histologic findings and, in cases of variants of MF, because of the unusual clinical and/or pathologic features. In this review, we presented the most frequent variants of MF at early stage including hypopigmented, folliculotropic, pagetoid reticulosis, unilesional, granulomatous, and ichthyosis forms. This case-based clinicopathologic review provides the notion that a comprehensive clinicopathologic correlation is of substantial importance to render the diagnosis of MF. In addition, we discuss the role of molecular studies, which are highly sensitive and recently more applicable to routinely processed skin biopsy specimens in the diagnosis of MF.

Merkel Cell Polyomavirus Small T Antigen Activates Noncanonical NF-κB Signaling to Promote Tumorigenesis.

Multiple human polyomaviruses (HPyV) can infect the skin, but only Merkel cell polyomavirus (MCPyV) has been implicated in the development of a cancer, Merkel cell carcinoma (MCC). While expression of HPyV6, HPyV7, and MCPyV small T antigens (sT), all induced a senescence-associated secretory phenotype (SASP), MCPyV sT uniquely activated noncanonical NF-κB (ncNF-κB), instead of canonical NF-κB signaling, to evade p53-mediated cellular senescence. Through its large T stabilization domain, MCPyV sT activated ncNF-κB signaling both by inducing H3K4 trimethylation-mediated increases of NFKB2 and RELB transcription and also by promoting NFKB2 stabilization and activation through FBXW7 inhibition. Noncanonical NF-κB signaling was required for SASP cytokine secretion, which promoted the proliferation of MCPyV sT-expressing cells through autocrine signaling. Virus-positive MCC cell lines and tumors showed ncNF-κB pathway activation and SASP gene expression, and the inhibition of ncNF-κB signaling prevented VP-MCC cell growth in vitro and in xenografts. We identify MCPyV sT-induced ncNF-κB signaling as an essential tumorigenic pathway in MCC. IMPLICATIONS: This work is the first to identify the activation of ncNF-κB signaling by any polyomavirus and its critical role in MCC tumorigenesis.

Sonic hedgehog signaling proteins and ATP-binding cassette G2 are aberrantly expressed in diffuse large B-cell lymphoma.

Dysregulation of the sonic hedgehog (SHH) signaling pathway has been shown in several cancer types, but has not been explored in diffuse large B-cell lymphoma. We assessed 67 cases of diffuse large B-cell lymphoma for expression of SHH (ligand), GLI1, GLI2 and GLI3 (transcriptional effectors of SHH signaling), and the ATP-binding cassette (ABC)G2 (a downstream target of SHH signaling), using immunohistochemistry. For comparison, we assessed the expression levels of these proteins in 28 cases of follicular lymphoma, 5 chronic lymphocytic leukemia/small lymphocytic lymphoma, and 5 reactive lymph nodes. In diffuse large B-cell lymphoma, SHH was expressed in 61 of 67 (91%) cases, GLI1 in 62 of 67 (93%), GLI2 in 41 of 56 (73%), and GLI3 in 22 of 56 (39%). Expression of ABCG2 was detected in 52 of 55 (95%) cases and was high in 15 (27%) cases. SHH expression positively correlated with expression levels of ABCG2 (P=0.05). Patients with diffuse large B-cell lymphoma with high ABCG2 expression showed significantly shorter overall survival (P=0.031) and failure-free survival (P=0.029) compared with patients with tumors with low or no expression of ABCG2. Diffuse large B-cell lymphomas expressed SHH, and GLI1, GLI2, and GLI3 more frequently and more intensely than cases of follicular lymphoma or chronic lymphocytic leukemia/small lymphocytic lymphoma. In conclusion, our data show that SHH signaling proteins and ABCG2 are aberrantly expressed in diffuse large B-cell lymphoma and that ABCG2 expression has prognostic implications. These findings also provide evidence that dysregulation of the SHH pathway may be involved in the pathogenesis of diffuse large B-cell lymphoma.

Stasis Mucinosis: Insights Into Euthyroid Localized Mucinosis.

INTRODUCTION: Stasis mucinosis and obesity-associated lymphedematous mucinosis (OALM) have been described as 2 discrete diagnostic entities. CASE REPORT: A morbidly obese African American man in his late 60s presented to the emergency room with a 3-month history of swelling of both lower extremities and secondary changes suggestive of lymphedema and venous dermatitis. On physical examination, the patient had severe edema with multiple raised areas of verruciform skin changes and varicosities, diffuse induration, erythema, and scaling. He also had an open wound in his left hallux. The skin biopsy found mucinosis. A diagnosis of stasis mucinosis was rendered. He had normal thyroid function test laboratory results. CONCLUSIONS: The authors suggest stasis mucinosis and OALM represent the spectrum of euthyroid mucin depositional disease in varying clinical settings.

Splenic marginal zone lymphomas are characterized by loss of interstitial regions of chromosome 7q, 7q31.32 and 7q36.2 that include the protection of telomere 1 (POT1) and sonic hedgehog (SHH) genes.

To further characterize the genotypic features of splenic (S) and nodal (N) marginal zone lymphomas (MZL) we compared eight SMZL and five NMZL by array-based comparative genomic hybridization (aCGH). Arbitrarily, aberrations were divided into major imbalances, defined as gains or losses involving five or more contiguous genetic loci, and minor imbalances, defined as those involving four or fewer loci. SMZL, but not NMZL, demonstrated major imbalances. These included deletions involving various lengths of 7q (three cases), and 14q23q24 (one case) and gains of 9p13p21 (one case), 13q21q33 (one case) and 16p13.1 (one case). Common minor imbalances in SMZL were: loss of sonic hedgehog gene (SHH) at 7q36.2 (four cases), loss of protection of telomere 1 gene (POT1) at 7q31.32 (three cases), and gain of glioma associated oncogene 1 (GLI1) at 12q13.2 (three cases). Common minor alterations in NMZL were: loss of the fas-associated via death domain gene (FADD) at 11q13.2 (three cases) and gain of GLI1 (five cases). In conclusion, SMZL, but not NMZL, demonstrates large genomic imbalances and frequent loss of the 7q31.32 and 7q36.2 regions involving POT1 and SHH, respectively. In NMZL, loss of FADD and gain of GLI1 are frequent events.

Leukemia cutis.

Leukemia cutis (LC) is a nonspecific term used for cutaneous manifestations of any type of leukemia. LC has a wide range of cutaneous manifestations, which can make it difficult to clinically distinguish LC from other skin lesions. Patients with LC usually have concomitant systemic leukemia, but occasionally skin involvement precedes the involvement of the bone marrow or peripheral blood. Thus, a skin biopsy can be the first indication of the presence of leukemia in a subset of patients. The immunophenotyping of routinely processed skin biopsy specimens is very useful in establishing the diagnosis of LC. Although the molecular mechanisms explaining the pathogenesis of LC are not well defined, chemokine receptors and adhesion molecules may have an important role in skin tropism. We review the literature and recent advances pertaining to LC, with special emphasis on the immunohistochemical assessment and possible mechanisms involved in skin tropism by leukemic cells.