Abstract Introduction Colorectal carcinoma (CRC) is the most common gastrointestinal neoplasm in the world, accounting for 15% of cancer-related deaths. This condition is related to different molecular pathways, among them the recently described serrated pathway, whose characteristic entities, serrated lesions, have undergone important changes in their names and diagnostic criteria in the past thirty years. The multiplicity of denominations and criteria over the last years may be responsible for the low interobserver concordance (IOC) described in the literature. Objectives The present study aims to describe the evolution in classification of serrated lesions, based on the last three publications of theWorld Health Organization (WHO) and the reproducibility of these criteria by pathologists, based on the evaluation of the IOC. Methods A search was conducted in the PubMed, ResearchGate and Portal Capes databases, with the following terms: sessile serrated lesion; serrated lesions; serrated adenoma; interobserver concordance; andreproducibility.Articlespublished since 1990were researched. Results and Discussion The classification of serrated lesions in the past thirty years showed different denominations and diagnostic criteria. The reproducibility and IOC of these criteria in the literature, based on the kappa coefficient, varied in most studies, from very poor to moderate. Conclusions Interobserver concordance and the reproducibility of microscopic criteria may represent a limitation for the diagnosis andappropriatemanagementof these lesions. It is necessary to investigate diagnostic tools to improve the performance of the pathologist’s evaluation, for better concordance, and, consequently, adequate diagnosis and treatment.

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.

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.

O líquen aureus (também denominado "liquen purpuricus") é um subtipo pouco comum entre as dermatoses purpúricas pigmentadas. Clinicamente caracterizado por máculas, pápulas ou placas de coloração ferruginosa, é doença crônica, que acomete mais frequentemente adultos jovens e localiza-se principalmente nos membros inferiores. O diagnóstico pode ser feito a partir das características clínicas e histopatológicas, sendo os achados dermatoscópicos úteis para corroborar o diagnóstico clínico.

Lichen aureus (also called "lichen purpuricus") is an uncommon subtype of pigmented purpuric dermatosis. Clinically characterized by rust macules, papules or plaques, it is a chronic disease which more often affects young adults and is localized mainly on the lower extremities. The diagnosis is made on the basis of clinical and histopathological features. Dermoscopy findings are useful to confirm clinical diagnosis.

Tumor benigno de tecido muscular, o piloleiomioma tem origem no músculo eretor do pelo, atingindo ambos os sexos geralmente na terceira década de vida. Apresenta-se como nódulo-pápulas assimétricas nas extremidades, de cor eritêmato-acastanhada e de consistência firme. As lesões, quando múltiplas, podem ser sensíveis ou dolorosas. Sua associação com miomas uterinos, denominada de síndrome de Reed ou leiomiomatose cutis et uteri, é apresentação rara, podendo estar associada a carcinoma de células renais. A abordagem é cirúrgica em casos isolados e medicamentosa se houver sintomas. Relatamos um caso de síndrome de Reed em que se optou por acompanhamento pela ausência de sintomatologia.

Piloleiomyoma, a benign smooth-muscle tumor arising from the arrectores pilorum muscles of the skin, affects males and females in the third decade of life. It presents as asymmetrical, reddish-brown nodules or papules with a firm consistency, predominantly located on the limbs. When multiple lesions are present, they may be tender or painful. Their association with uterine fibroids, referred to as Reed syndrome or familial leiomyomatosis cutis et uteri, is rare and may be associated with renal cell carcinoma. The approach consists of surgical excision in cases presenting few lesions and pharmacological treatment if symptomatic. The present paper describes a case of Reed syndrome in which a decision was made to monitor the patient in view of the absence of symptoms.