[The skin biopsy]

[Malignant head and neck melanoma : Part 1: Diagnosis and histological particularities]

About 15% of all cutaneous melanomas develop in the head and neck region. Mucosal melanomas are rare and represent only 1% of all melanomas, however, most frequently, these are located in the nose, the paranasal sinuses and the oral cavity. Visual diagnosis and reflected-light microscopy are relevant for the evaluation of melanoma-suspect lesions. Histological investigation of resected tumors need special skills of the histopathologist and includes in case of high-risk tumors investigations of mutations in the tumor tissue concerning NRAS, BRAF and KIT. The risk of lymphatic or hematogeneous spread rises with increasing tumor thickness and the presence of further prognostic risk factors such as ulceration of the primary tumor or the presence of mitoses within the tumor.

Basic concepts in skin biopsy. Part I

The aim of these reviews is to describe the reasons for performing skin biopsy, to provide indications for the choice of area to be biopsied and the preparation of the sample, and to summarize the various complications of dermatologic surgery. In addition, we present a guide for selecting the biopsy technique based on the suspected diagnosis and on the area to be biopsied. Finally, the various artifacts that can complicate interpretation of results are described, together with the methods used to prevent their appearance insofar as is possible. The aim of this guide is to improve the diagnostic yield of biopsies and to highlight the importance of a correct clinical-histological correlation.

Histopathology of panniculitis--aspects of biopsy techniques and difficulties in diagnosis

BACKGROUND

Clinical and histologic diagnosis of panniculitis may be difficult. The patients usually present with erythematous subcutaneous nodules with or without additional symptoms. If a skin biopsy does not include enough subcutaneous fat, histopathologic assessment is limited and the correct diagnosis may be delayed and require further sampling.

PATIENTS AND METHODS

To illustrate the difficulties in the diagnosis of panniculitis, we performed a retrospective examination of four patients with different forms of panniculitis.

RESULTS

In two patients with subcutaneous panniculitis-like T cell lymphoma and lupus panniculitis, the correct diagnosis could only be ascertained after a delay of several months because repeated biopsies had to be obtained throughout the course of disease. In two further patients with cold panniculitis and pancreatic panniculitis, clinicians did not even suspect an inflammatory process in the subcutaneous tissue. The correct diagnosis was made with a deep punch biopsy that included subcutaneous fat.

CONCLUSIONS

On the one hand, these examples demonstrate the importance of sampling subcutaneous tissue when obtaining routine punch biopsies. On the other hand, in cases where the diagnosis is uncertain, it is necessary to perform large and deep incisional biopsies.

[Basic concepts in skin biopsy. Part I]

The aim of these reviews is to describe the reasons for performing skin biopsy, to provide indications for the choice of area to be biopsied and the preparation of the sample, and to summarize the various complications of dermatologic surgery. In addition, we present a guide for selecting the biopsy technique based on the suspected diagnosis and on the area to be biopsied. Finally, the various artifacts that can complicate interpretation of results are described, together with the methods used to prevent their appearance insofar as is possible. The aim of this guide is to improve the diagnostic yield of biopsies and to highlight the importance of a correct clinical-histological correlation.