Immunohistochemical and molecular analysis of spitzoid neoplasms with pulverocyte subclones.

BACKGROUND: Clonal naevi are characterized by a focal proliferation of pigmented melanocytes in an otherwise banal naevus. These subclones are often composed of aggregates of larger, epithelioid melanocytes with nuclear atypia and dusty-grey cytoplasmic pigmentation, which are referred to as 'pulverocytes', and this finding may lead to a misdiagnosis of malignant melanoma (MM). AIM: To characterize the significance of subclones of dusty-grey pigmented epithelioid melanocytes within spitzoid neoplasms. METHODS: We studied the histological and molecular features of a series of 20 spitzoid neoplasms with pulverocyte subclones encountered in our practice, including both atypical Spitz tumours (ASTs) and invasive MMs. RESULTS: Pulverocytes were predominantly dermal, and the percentage of subclones ranged from 2% to 40%, with a median of 10% in ASTs and 25% in lesions we classified as MM. In cases with > 10% subclones, there was an increased odds of fluorescence in situ hybridization positivity (OR = 12; 95% CI 1.2-293.4; P = 0.03) and an increased odds of homozygous 9p21 deletion (OR = 3.6; 95 CI 0.28-89.82; P = 0.33), although the latter did not reach statistical significance. CONCLUSIONS: We consider spitzoid lesions with a small subclone population to be a variant of a clonal naevus with indolent behaviour, whereas lesions with larger pulverocyte populations are more likely to have chromosomal copy number aberrations and in some cases may represent malignant transformation.

γδ T-cell-rich variants of pityriasis lichenoides and lymphomatoid papulosis: benign cutaneous disorders to be distinguished from aggressive cutaneous γδ T-cell lymphomas.

BACKGROUND: T cells with a γδ phenotype have been associated with aggressive lymphomas. Yet, inflammatory skin disorders and low-grade lymphoproliferative disorders have rarely been described with a predominant γδ T-cell infiltrate. OBJECTIVES: To review our experience and determine the clinical relevance of the γδ T-cell phenotype in lymphomatoid papulosis (LyP) and pityriasis lichenoides (PL). METHODS: A retrospective dermatopathology file review looking for LyP and PL characterized by a γδ T-cell phenotype was performed. Clinical manifestations and course, histological features and molecular data were analyzed. RESULTS: Six of 16 cases of LyP and four of 23 cases diagnosed as PL during a 5-year period (2009-14) were identified. The median follow-up for the whole group was 16 months (range 3-64), showing an indolent clinical course in all cases. CONCLUSIONS: The detection of a predominantly γδ T-cell phenotype in papular lymphoid-rich infiltrates in the absence of other lesions is not associated with a clinically aggressive course. γδ T-cell-rich variants of LyP and PL may reflect a spectrum of related conditions. This is a single academic centre retrospective chart review of a relatively small sample.

Fluorescence in situ hybridization for ambiguous melanocytic tumors.

The large majority of melanocytic lesions can be reliably classified as either benign or malignant based upon morphology alone, but a minority of lesions remains difficult to classify by traditional histologic methods. Recently, a panel of fluorescence in situ hybridization (FISH) probes targeting loci on chromosomes 6 and 11 has emerged as a powerful tool to discriminate melanoma from nevi. This has been validated in numerous difficult diagnostic scenarios. In addition, this same FISH panel has been shown to provide independent prognostic information in traditional melanomas. There is accumulating evidence that FISH targeting these loci as well as several other key chromosomal loci such as 9p21 and 8q24 can provide valuable prognostic information in histologically ambiguous melanocytic tumors. However, since the vast majority of atypical spitz tumors have an indolent course, larger studies including adequate numbers of cases with adverse events is necessary to provide sufficient proof of its role in clinically relevant cases. In this review, we discuss the current literature and studies to date on this topic.

Fluorescence in situ hybridization as a diagnostic modality in melanocytic neoplasma.

It has well been established by comparative genomic hybridizations that melanocytic neoplasms have chromosomal copy number aberrations not seen in benign melanocytic nevi. In a rigorous study involving over 400 melanocytic neoplasms we recently evaluated the potential of a number of chromosomal loci frequently altered in melanoma but not in nevi as potential targets for a fluorescence in situ based assay. After evaluating 14 potential chromosomal loci arranged in various 4 probe panels, 6p25, 6q23, Cep6 and 11q13 were identified as the combination of targets best able to differentiate between malignant melanoma and benign nevi. Melanocytic neoplasms were considered as positive for melanoma if any of the following criteria were met; greater than 29% of enumerated cells showed gains in 6p25; greater than 38% of cells showed gains in 11q13; greater than 55% of cells show more copies of 6p25 than Cep6; or if greater than 42% of cells have less copies of 6q23 than Cep6. In a validation set, this 4 probe assay targeting these loci was able to differentiate between melanoma and nevi with a sensitivity of 86.7% and specificity of 95.4%. In this paper we review the multiple steps involved in development of this assay as well as the subsequent performance of this assay in a number of studies looking at its utility in specific differential diagnoses in melanocytic pathology.

Interleukins in the treatment of mycosis fungoides.

Mycosis fungoides is typified by a cutaneous infiltrate of CD4+ lymphocytes with a Th2 phenotype. As the disease advances, there is increased expression of Th2 cytokines. This results in a subsequent suppression of Th1 cytokines and impaired cell mediated cytotoxic host response to the lymphoma cells. Disarming this cell mediate cytotoxic immune response creates a relentless cycle of disease progression. A cell mediated cytotoxic immune response can be stimulated with the use of Th1 cytokines such as IL-2 and IL-12. In this report, the Authors review the rational for the use of these particular cytokines in the treatment of mycosis fungoides. Further they comment on the experience and success regarding these two agents in phase I and II trials for the treatment of mycosis fungoides. Lastly, they discuss other potential cytokine therapies which could play a role in the future treatment of mycosis fungoides.

Hand foot skin reaction in cancer patients treated with the multikinase inhibitors sorafenib and sunitinib.

BACKGROUND: This study examined clinicopathological findings and management of hand foot skin reaction (HFSR) to sorafenib and sunitinib in a dermatology referral center for cancer-related toxic effects. PATIENTS AND METHODS: We identified 12 patients who developed HFSR in a 1-year period (2007). Medical records and histological specimens were investigated for clinicopathological data and results on management. RESULTS: We identified 12 patients developing HFSR on treatment with sorafenib (83%) or sunitinib (17%). Majority presented with grade 3 (75%) HFSR and a median Skindex score of 43. Biopsies in seven patients showed horizontal layers of keratinocyte necrosis, which correlated to time of drug exposure: early (<30 days from initiation) leading to stratum granulosum-spinosum alterations and late (> or =30 days) resulting in stratum corneum pathology. Treatment with topical urea singly (n = 3), plus tazarotene (n = 7), or fluorouracil (n = 2) resulted in > or =2 grade improvement in the majority of patients (58%), with five patients (42%) improving one grade (P = 0.007). Median Skindex score at follow-up was 32 (P = 0.22). CONCLUSIONS: There are unique clinicopathological characteristics of HFSR due to the multikinase inhibitors that correlate with time of agent initiation. Treatment with topical agents having keratolytic, antiproliferative, and anti-inflammatory properties showed benefit.

Follicular mycosis fungoides: a histopathologic, immunohistochemical, and genotypic review.

Follicular mycosis fungoides (FMF) is a recognized variant of mycosis fungoides. In this review, the authors characterize the distinct histopathological and immunohistochemical patterns of FMF that have been reported in the literature. This article is an extensive review of the literature cited in Medline and own data of the authors. The major patterns of FMF histopathology, immunohistochemistry, and molecular genetics are summarized in this review. Histologically, the quintessential finding in FMF is small to medium atypical CD3+ CD4+ CD8- T lymphocytes around and within the epithelium of the hair follicles. This finding is requisite to the diagnosis. However, this finding may be obscured by a host of other patterns often identified in FMF. This includes basaloid folliculo-lymphoid hyperplasia, a granulomatous reaction, eosinophilic folliculitis, and follicular cystic changes with subtle atypical lymphocytes in the cyst wall. Follicular mucinosis (MF) and syringo-tropism are also variably present. Immunohistochemistry of all reported cases uniformly show a CD4+ T cell infiltrate. This review emphasizes and discusses the broad spectrum of histologic changes which may be seen in FMF, clues to the diagnosis, and some potential mimickers.

A systematic review of juvenile-onset clinically amyopathic dermatomyositis.

BACKGROUND: Dermatomyositis (DM) presenting during childhood or adolescence classically encompasses hallmark cutaneous changes, proximal muscle weakness, and laboratory evidence of myositis. When cutaneous manifestations of DM are present without muscle weakness for > 6 months, the term 'clinically amyopathic DM' applies (syn. DM sine myositis). OBJECTIVES: To review the clinical and epidemiological features of published cases of juvenile-onset clinically amyopathic DM, with comparison with adult-onset clinically amyopathic DM and juvenile-onset classical DM. METHODS: Systematic review of the published literature. RESULTS: We identified 68 cases of juvenile-onset clinically amyopathic DM published during 1963-2006. The disease in 18 of 68 (26%) patients subsequently evolved to classical DM. Overall, the mean age at diagnosis was 10.8 years (range 2-17) with nearly equal male/female ratio and mean follow-up of 3.9 years. Among cases with diagnostic testing, 10 of 19 had a positive antinuclear antibody titre, two of nine had elevated erythrocyte sedimentation rate and two of 51 had elevated creatine kinase (CK). Of patients with normal CK, three of 22 had abnormal electromyography, one of 19 had abnormal muscle biopsy, and one of nine had abnormal magnetic resonance imaging. Calcinosis was reported in three of 68. No cases of severe vasculopathy (resulting in ulceration), interstitial lung disease or internal malignancy were reported. CONCLUSIONS: This review suggests a good prognosis for children with clinically amyopathic DM. A minority of patients with negative muscle enzymes had positive ancillary testing for myositis, and these patients rarely developed muscle weakness. Predictive factors for progression to classical DM were not identified. Symptomatic treatment of cutaneous involvement and close clinical monitoring may be an alternative to aggressive immunosuppression.