Desmoplastic melanoma associated with an intraepidermal lentiginous lesion: case report and literature review / Melanoma desmoplásico associado a lesão lentiginosa intraepidérmica, com evolução de 10 anos: relato de caso e revisão bibliográfica

Desmoplastic melanoma tends to present as firm, amelanotic papules. Microscopically, it reveals a proliferation of fusiform cells in the dermis and variable collagen deposition, as well as intraepidermal melanocytic proliferation of lentiginous type in most cases. Biopsy in a 61-year-old white male patient, who had received a diagnosis of lentigo maligna on his face 10 years before, revealed a proliferation of dermal pigmented spindle cells and collagen deposition, reaching the deep reticular dermis, with a lentiginous component. Immunohistochemistry with S-100, Melan-A and WT1 showed positivity, but it was weak with HMB45. Desmoplastic melanoma associated with lentigo maligna was diagnosed. Several authors discuss whether desmoplastic melanoma represents a progression from the lentiginous component or arises "de novo". Desmoplastic melanoma represents a minority of cases of primary cutaneous melanoma (less than 4%). Identification of lentigo maligna indicates that desmoplastic melanoma should be carefully investigated.

Os melanomas desmoplásicos apresentam-se como pápulas amelanóticas firmes; à microscopia exibem proliferação de células fusiformes na derme e variável deposição de colágeno, além de proliferação melanocítica lentiginosa, intraepidérmica, na maioria dos casos. Realizada biópsia de pele de paciente masculino, 61 anos, branco, com diagnóstico de lentigo maligno na face, há 10 anos. O exame histopatológico revela proliferação dérmica de células fusiformes pigmentadas e deposição de colágeno, invadindo até a profundidade da derme reticular, associado a componente lentiginoso; presença de positividade imuno-histoquímica com S-100, Melan-A e WT1, e marcação fraca com HMB45. Diagnóstico de melanoma desmoplásico, associado a lentigo maligno. Existe divergência quanto à origem do melanoma desmoplásico, a partir do componente lentiginoso ou "de novo", na ausência de lentigo associado. O melanoma desmoplásico representa uma minoria dos casos de melanoma cutâneo primário (menos de 4%). A presença de lentigo maligno pode servir de sinal de alerta para possível relação com melanoma desmoplásico.

Wilms tumor 1 protein is not expressed in oral lymphangiomas

Lymphangiomas are benign hamartomatous lesions of lymphatic vessels. Wilms Tumor 1 (WT1) is a transcription factor that is activated in some human neoplasias. WT1 protein expression is observed in endothelial cells during angiogenesis and is a useful marker to distinguish between vascular proliferations and vascular malformations. The purpose of the present study is to report a case series of oral lymphangiomas together with an immunohistochemical investigation of WT1. Seventeen cases of oral lymphangioma were retrieved and reviewed. Immunohistochemical analysis of WT1 protein was performed and pyogenic granuloma samples were used as positive controls. The male/female ratio was 1.125 and most of the lesions occurred in young subjects. While pyogenic granuloma showed positive staining for WT1, the endothelial cells lining the thin-walled dilated lymphatic vessels of lymphangiomas were negative for this protein. The findings strengthen the idea that oral lymphangioma is a vascular malformation characterized by lymphatic dilatation without significant endothelial proliferation.

Os linfangiomas são tumores hamartomatosos benignos dos vasos linfáticos. O Wilms Tumor 1 (WT1) é um fator de transcrição que se encontra ativo em algumas neoplasias humanas. A expressão da proteína WT1 é observada em células endoteliais durante a angiogênese e pode ser um marcador útil para distinguir as proliferações vasculares das malformações vasculares. O objetivo deste estudo foi relatar uma série de casos de linfangiomas orais e avaliar a expressão imunoistoquímica da proteína WT1. Dezessete casos de linfangiomas orais foram recuperados e revisados. A análise imunoistoquímica foi realizada e amostras de granuloma piogênico foram utilizadas como controle positivo. A relação homem/mulher foi de 1,125 e a maioria das lesões acometeram pacientes jovens. Enquanto o granuloma piogênico mostrou uma imunopositividade para WT1, as células endoteliais da fina parede dos vasos linfáticos dilatados apresentaram-se negativas para esta proteína. Tais achados reforçam a idéia de que o linfangioma oral é uma malformação vascular caracterizada por dilatação linfática sem uma proliferação endotelial significativa.

Clinical Significance of Quantitation of WT1 Gene Expression for Minimal Residual Disease Monitoring of Acute Myelogenous Leukemia / 대한진단검사의학회지

BACKGROUND: Following induction chemotherapy for AML, a sensitive determination of minimal residual disease (MRD) in patients achieving complete remission (CR) should enable the detection of early relapse. This study was designed to verify if quantitative assessment of the Wilms' tumor (WT1) gene by real time polymerase chain reaction (RQ-PCR) can be used as a marker for MRD detection during the monitoring of AML. METHODS: WT1 gene expression was quantified by RQ-PCR in 31 patients with AML at diagnosis (27 patients) and during follow-up (29 patients) relative to ABL control gene. In four patients, the WT1 gene expression was analyzed in comparison to a second PCR marker, PML-RARA fusion transcript. Prognostic significance of WT1 gene expression was analyzed at diagnosis and at the primary CR evaluation. Longitudinal WT1 gene analysis was performed in 17 AML patients. RESULTS: At diagnosis, WT1 gene expression exceeded the control level in all of the patients. Higher levels of WT1 gene expression were not associated with shorter event free survival or overall survival at diagnosis. Higher levels of WT1 gene expression were associated with shorter event free survival after induction chemotherapy. Relapse was observed in eight of 17 patients analysed longitudinally, and an increase of WT1 gene expression preceded morphologic relapse in four patients with the fusion transcript negative. Concomitant monitoring of PML-RARA fusion transcript reveals the lack of a significant correlation withWT1 gene expression. CONCLUSIONS: Quantitation of WT1 gene expression could be used for MRD monitoring of AML and for the early detection of relapse, especially in patients lacking specific molecular markers.