Multiple Eruptive Epithelioid Hemangiomas: A Subset of Cutaneous Cellular Epithelioid Hemangioma With Expression of FOS-B.

There is a wide clinicopathologic spectrum of vascular proliferations characterized by the presence of epithelioid endothelial cells, comprising epithelioid hemangioma (EH)-pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma (PM-HAE), epithelioid hemangioendothelioma, and epithelioid angiosarcoma. Immunohistochemical FOS-B expression as well as FOS-B rearrangement (fluorescent in situ hybridization [FISH]) have recently been described as diagnostically relevant underpinnings of EH (restricted to osseous lesions) and PM-HAE. The aim of this study was to clinicopathologically characterize and to elucidate FOS-B expression in patients with eruptive lesions of the cellular variant of cutaneous EH.

Dermoscopy pathology correlation in melanoma.

Dermoscopy is a widely used technique whose role in the clinical (and preoperative) diagnosis of melanocytic and non-melanocytic skin lesions has been well established in recent years. The aim of this paper is to clarify the correlations between the "local" dermoscopic findings in melanoma and the underlying histology, in order to help clinicians in routine practice.

'Hints' in the horn: diagnostic clues in the stratum corneum.

The stratum corneum or horny layer is the uppermost layer of the epidermis, and is mainly responsible for the skin's barrier function. In spite of its complexity at the ultrastructural and molecular level, the features accessible to visualization on conventional histology are relatively limited. Nevertheless, knowledge of subtle clues that one may observe in the stratum corneum can prove useful in a wide range of situations in dermatopathology.

Fluorescence In Situ Hybridization for Melanoma Diagnosis: A Review and a Reappraisal.

Although conventional histopathological examination is the undisputable mainstay for the diagnosis of melanocytic skin neoplasms, fluorescence in situ hybridization (FISH) has the potential to provide important information to morphologically challenging cases. The standard melanoma FISH test targeting RREB1 (6p25), MYB (6q23), CCND1 (11q13), and centromere 6 is an effective compromise between cost, technical complexity, and sensitivity. The authors use the standard FISH-positivity as a tie-breaker for challenging melanocytic neoplasms mainly in a non-Spitzoid morphologic context because the currently available test leaves several unresolved issues: namely, a relatively low diagnostic accuracy in morphologically ambiguous melanocytic neoplasms; a relatively low sensitivity and specificity in Spitzoid neoplasms; and the occurrence of false positives due to tetraploidy in Spitz nevi and in nevi with an atypical epithelioid component.

Atypical dermoscopic presentation of an acral congenital melanocytic nevus in an adult: parallel ridge pattern and its histologic correlation.

Acral melanoma is the most frequent subtype in the Asian and Mexican mestizo populations. Dermoscopy is a noninvasive diagnostic technique that helps the differential diagnosis of pigmented skin lesions on acral volar skin. We, herein, present a case of acral congenital melanocytic nevus with a parallel ridge dermoscopic pattern.

Clinical and dermoscopic features of atypical Spitz tumors: A multicenter, retrospective, case-control study.

Background: Few studies have described the clinical and dermoscopic features of atypical Spitz tumors.

Objective: We sought to describe the clinical and dermoscopic features of a series of atypical Spitz tumors as compared with those of conventional Spitz nevi.

Methods: This was a multicenter, retrospective, case-control study, analyzing the clinical and dermoscopic characteristics of 55 atypical Spitz tumors and 110 Spitz nevi that were excised and diagnosed histopathologically.

Prior knowledge of the clinical picture does not introduce bias in the histopathologic diagnosis of melanocytic skin lesions.

A common debate among dermatopathologists is that prior knowledge of the clinical picture of melanocytic skin neoplasms may introduce a potential bias in the histopathologic examination. Histologic slides from 99 melanocytic skin neoplasms were circulated among 10 clinical dermatologists, all of them formally trained and board-certified dermatopathologists: 5 dermatopathologists had clinical images available after a 'blind' examination (Group 1); the other 5 had clinical images available before microscopic examination (Group 2). Data from the two groups were compared regarding 'consensus' (a diagnosis in agreement by ≥4 dermatopathologists/group), chance-corrected interobserver agreement (Fleiss' k) and level of diagnostic confidence (LDC: a 1-5 arbitrary scale indicating 'increasing reliability' of any given diagnosis).

Atypical Spitz tumours and sentinel lymph node biopsy: a systematic review.

Sentinel lymph node biopsy has been proposed as a diagnostic method for estimation of the malignant potential of atypical Spitz tumours. However, although cell deposits are commonly detected in the sentinel lymph nodes of patients with atypical Spitz tumours, their prognosis is substantially better than that of patients with melanoma and positive sentinel lymph node biopsies. We did a systematic review of published reports to assess the role of sentinel lymph node biopsy as a prognostic method in the management of atypical Spitz tumours.

A specific DNA methylation profile correlates with a high risk of disease progression in stage I classical (Alibert-Bazin type) mycosis fungoides.

Background: Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma; in its classical presentation it evolves slowly, but it can have an aggressive course in a subset of patients.

Objectives: To investigate the impact of epigenetic mechanisms on the progression of early stage MF.

Methods: We analysed DNA methylation at 12 different loci and long interspersed nucleotide elements-1 (LINE-1), as a surrogate marker of global methylation, on tissue samples from 41 patients with stage I MF followed up for at least 12 years or until disease progression.

Accuracy of dermoscopic criteria for discriminating superficial from other subtypes of basal cell carcinoma.

Background: The management of basal cell carcinoma (BCC) depends, among other factors, on its histopathologic subtype. Although dermoscopic criteria of BCC have been investigated, the possible role of dermoscopy in predicting the tumor subtype remains unclear.

Objectives: We sought to assess the diagnostic accuracy of dermoscopic criteria for differentiating superficial BCC (sBCC) from other BCC subtypes.

Spitz nevus, Spitz tumor, and spitzoid melanoma: a comprehensive clinicopathologic overview.

Spitz nevus can clinically present either in the classical (reddish pink) or the pigmented (brownish black) variant. Dermoscopy demonstrates that the pigmented variant is much more common than the classical variant; however, none of these show dermoscopic patterns clearly distinguishable from melanoma. Even histopathologically, a clear-cut differentiation between benign and malignant spitzoid neoplasms is often difficult, so that intermediate diagnostic categories (atypical Spitz nevus and Spitz tumor) are admitted.

Main clues in the pathologic diagnosis of melanoma: is molecular genetics helping?

Although conventional histopathologic examination is still the undisputable mainstay for the diagnosis of melanocytic skin neoplasms, application of molecular testing has experienced tremendous growth and will continue to expand in the future as the need for more specific diagnoses and new targeted therapies evolve. Ancillary molecular methods, including comparative genomic hybridization and fluorescence in situ hybridization, have the potential to provide important new information to challenging cases, and will help improve diagnostic accuracy, particularly in cases in which morphology is not conclusive. Pathologists are increasingly involved in the prospective genotyping of melanoma, which leads to patient stratification in light of the novel personalized therapeutic approaches in the advanced setting.

Primary cutaneous marginal zone B-cell lymphoma with anetoderma: spontaneous involution plus de novo clonal expansion.

We describe a rare case of primary cutaneous marginal zone B-cell lymphoma (PCMZL) in a 33-year-old male affected by hepatitis B virus (HBV)-related chronic active hepatitis. The patient presented with multiple cutaneous papulonodular lesions characterized by polymorphic immunomorphology, with inverse pattern of immunoglobulin light chain restriction in two different lesions, coupled with mucin deposition and anetoderma in a third lesion. The involution of lesions of PCMZL with secondary anetoderma has been previously described, but this has not been reported in the context of multiple lesions showing differing immunoglobulin light chain restriction.

B-cell lymphofollicular infiltrates in mycosis fungoides.

Aims And Background: The histopathological picture of mycosis fungoides can be characterized by heavy reactive infiltrates. These are rarely composed of B lymphocytes with formation of reactive follicles.

Methods And Study Design: We collected three cases of mycosis fungoides with a reactive B-cell lymphofollicular reaction at the bottom of the epidermotropic infiltrate.

Pediatric atypical spitzoid neoplasms: a review with emphasis on 'red' ('spitz') tumors and 'blue' ('blitz') tumors.

Background: The diagnosis of pediatric atypical Spitz nevus/tumors (pASNT) is an emerging challenge in clinical dermatology and dermatopathology.

Objective And Methods: We review the main clinicopathologic issues raised by pASNT and describe 2 examples of different clinicopathologic subsets of lesions.

Results: While Spitz/Reed nevi are commonly small- to medium-sized, tan to black plaques, pASNT are large and nodular, either 'red' (dotted and/or polymorphous vascular pattern on dermoscopy; spindle and/or epithelioid tumors on histopathology: Spitz tumors, sensu strictiori) or 'blue' (homogeneous blue color on dermoscopy; intimate admixture of epithelioid cells and heavily pigmented dendritic cells on histopathology: Blitz tumors or pigmented epithelioid melanocytomas).

Free-floating collagen fibers in interstitial mycosis fungoides.

We present a case of interstitial mycosis fungoides showing pseudodovascular clefts with "free-floating" collagen fibers surrounded by neoplastic T lymphocytes. Such a finding further expands the histopathologic spectrum of mycosis fungoides and could be taken into account in its differential diagnosis from granuloma annulare, inflammatory morphea, and interstitial granulomatous drug reaction.