Diagnosis and Treatment of Merkel Cell Carcinoma in Specialized Dermatology Units: A Clinical Practice Guideline of the Spanish Academy of Dermatology and Venereology. / Carcinoma de células de Merkel: diagnóstico y tratamiento en atención especializada dermatológica. Guía de práctica clínica de la Academia Española de Dermatología y Venerología.

BACKGROUND AND OBJECTIVE: Merkel cell carcinoma is a rare, aggressive skin cancer that is managed in a great variety of ways. However, international clinical practice guidelines give only partial coverage to issues considered major problems.The recommendations presented here aim to provide Spanish dermatologists with a guide to improving disputed aspects of diagnosis, staging, and treatment of localized Merkel cell carcinomas. MATERIAL AND METHODS: The ADAPTE process was used. Members of the Spanish Group of Oncologic Dermatology and Surgery (GEDOC) with experience in treating Merkel cell carcinoma and interest in drafting these guidelines were selected. The group described the care process and listed the most important clinical questions. They then searched for guidelines and assessed them with the AGREE II (Appraisal of Guidelines for Research and Evaluation) tool. After consulting the guidelines for answers to their clinical questions, the group drafted the present statementand sent it for external review. RESULTS: The guidelines that scored highest in the AGREE II assessment step were the consensus-based interdisciplinary guideline of the European Association of Dermato-Oncology and the European Organization of Research and Treatment of Cancer, and those of the Comprehensive Cancer Network, the Alberta Health Services in Canada, the American Cancer Society, and the Cutaneous Oncology Group of the French Society of Dermatology. A total of 9 clinical questions were answered based on these guidelines. CONCLUSIONS: The guidelines presented here answer clinical questions that arise in routine practice. They can provide dermatologists with a starting point for decision-making, although available resources and patient preferences must always be borne in mind.

Multiple pilosebaceous cysts.

We report two patients initially diagnosed as having steatocystoma multiplex (SM). Other cysts showed characteristics of eruptive vellus hair cyst (EVHC). More than 30 and 14 cysts, respectively, were removed with histological hybrid characteristics of SM and EVHC. This suggests that SM and EVCH are two closely related entities, which represent a naevoid malformation in the area where the sebaceous duct and hair follicle meet.

Metastatic melanoma of unknown primary tumor.

The appearance of metastasis without clinically demonstrable primary tumor is one of melanoma's challenges. The aim of this study was to recognize the specific characteristics of this occurrence. Based on our study of three patients, we have proposed theories to explain this behavior, its clinical approach, and therapeutic management. We conclude by stressing the importance of finding the primary tumor or traces of it.

Occult spinal dysraphism: a neurosurgical problem with a dermatologic hallmark.

Lumbosacral congenital cutaneous lesions have been recognized for a long time by neurologists and neurosurgeons as markers of occult spinal defects, but only a few cases have been published and discussed in the dermatologic literature. Based on a case report, we emphasize the importance of early diagnosis of these lesions, the use of new diagnostic techniques, and the correct management.

Squamous cell carcinoma arising from a lesion of disseminated superficial actinic porokeratosis.

We report a 69-year-old man with disseminated superficial actinic porokeratosis (DSAP) who developed a hyperkeratotic lesion on the distal third of the right forearm with the characteristic histopathological findings of squamous cell carcinoma and DSAP. A review of the literature revealed only four similar cases.

Inflammatory metastatic carcinoma. A clinical and histopathologic study of three cases.

The inflammatory metastatic carcinoma is a rare clinical entity, histologically characterized by lymphatic dermal invasion by neoplastic cells. We report three cases of inflammatory metastatic carcinoma, two of them secondary to a breast carcinoma, and the third secondary to a colon adenocarcinoma.

Subepidermal calcified nodule.

The subepidermal calcified nodule (SNC), included under the idiopathic cutaneous calcifications, is an infrequent cutaneous process. We report a new case localized on the chin of an 18 month old child. We review the concept gathered from previous literature and we post the possible role which the mast cell may play in the genesis of the said deposits.

[Keratoacanthoma over the donor site of a laminar skin graft]. / Queratoacantoma sobre zona dadora de injerto laminar.

We present a case of keratoacanthoma type II in a 38-year-old female patient, which developed in the thigh over the donor site of a laminar skin graft, six weeks after the procedure. The graft was utilized to cover the defect secondary to the resection of a melanoma. The possible role played by mechanical trauma in the development of this tumor, rare under such circumstances, is discussed. Similar previously published cases are reviewed.