How to get the most out of your skin biopsies

Considerations in geriatric dermatopathology

This review provides an overview of considerations in geriatric dermatopathology. The nuances of specimen collection and reporting in this population, including the importance of obtaining adequate tissue, providing detailed clinical information and ethical considerations surrounding specimen collection will be discussed. The histopathologic changes associated with aging and the morphologic features of common lesions related to photoaging are outlined followed by a discussion of common interpretation pitfalls, specifically entities at risk of overinterpretation and those related to hyper- and hypopigmentation. Finally, the recent literature is reviewed regarding special cases and what this implies for future research both in dermatology and dermatopathology.

Dermatopathological Correlation of Clinically Challenging Cutaneous Lesions: a Single Center Experience of 2184 Cases

INTRODUCTION

Although a trained eye can easily identify typical skin lesions, histopathological examination and clinicopathological correlation are critical in challenging cases.

OBJECTIVES

The primary objective is to organize the final diagnoses reached following clinicopathological consensus in clinically challenging cutaneous lesions, identifying the most common diagnostic scenarios encountered by dermatopathologists and discussing their diverse differentials submitted by clinicians. The secondary objective is to investigate how the case profile and clinician decision-making processes evolved during the COVID-19 pandemic.

METHODS

Skin and mucosa samples collected by the dermatology department between 2016 and 2020 were classified based on pathology reports. For frequent diagnoses, preliminary diagnoses stated by clinicians on pathology requisition forms were reviewed. The years preceding and following the first nationally reported COVID-19 case were compared to investigate the pandemic's impact on the distribution of dermatology and dermatopathology cases.

RESULTS

One thousand nine hundred and eighty-nine reports were classified into 4 major categories: inflammatory (49.8%), neoplastic (30.1%), other diseases (7.1%), and non-diagnostic (12.8%). We further classified inflammatory diseases based on major tissue reaction patterns and neoplasms based on cell origin. We analyzed the leading diagnoses in each category, discussed their differential diagnoses, and provided clinicians with clues to reduce errors in practice. Following the pandemic, the overall number of pathology reports and patient admissions dropped dramatically, with significant changes in case profiles.

CONCLUSIONS

We presented and discussed the frequently encountered confounding cases to sketch the diagnostic landscape. In the authors' experience, clinicopathological correlation can increase the rate of reaching the diagnosis by up to 75.3%.

Overdiagnosis of melanoma - causes, consequences and solutions

Malignant melanoma is the skin tumor that causes most deaths in Germany. At an early stage, melanoma is well treatable, so early detection is essential. However, the skin cancer screening program in Germany has been criticized because although melanomas have been diagnosed more frequently since introduction of the program, the mortality from malignant melanoma has not decreased. This indicates that the observed increase in melanoma diagnoses be due to overdiagnosis, i.e. to the detection of lesions that would never have created serious health problems for the patients. One of the reasons is the challenging distinction between some benign and malignant lesions. In addition, there may be lesions that are biologically equivocal, and other lesions that are classified as malignant according to current criteria, but that grow so slowly that they would never have posed a threat to patient's life. So far, these "indolent" melanomas cannot be identified reliably due to a lack of biomarkers. Moreover, the likelihood that an in-situ melanoma will progress to an invasive tumor still cannot be determined with any certainty. When benign lesions are diagnosed as melanoma, the consequences are unnecessary psychological and physical stress for the affected patients and incurred therapy costs. Vice versa, underdiagnoses in the sense of overlooked melanomas can adversely affect patients' prognoses and may necessitate more intense therapies. Novel diagnostic options could reduce the number of over- and underdiagnoses and contribute to more objective diagnoses in borderline cases. One strategy that has yielded promising results in pilot studies is the use of artificial intelligence-based diagnostic tools. However, these applications still await translation into clinical and pathological routine.

Coexistent dermatofibrosarcoma protuberans and anticonvulsant-induced cutaneous lymphoid hyperplasia: diagnostic challenge

A 60-year-old African-American male patient with a history of seizures, developmental delay, long history of behavioural issues with psychotic episodes, heart, liver, thyroid and kidney diseases presented for evaluation of a right neck skin lesion. Physical examination revealed a shiny purplish-red plaque on the right neck and a thin pink plaque on the posterior neck. The lesions were similar in appearance, but different enough to warrant skin biopsy of each. Pathology demonstrated mycosis fungoides (MF) on the right neck and dermatofibrosarcoma protuberans (DFSP) on the posterior neck. The identification of two rare conditions made us reconsider our diagnosis. After further review, the right neck skin lesion was thought to be anticonvulsant-induced cutaneous lymphoid hyperplasia, not MF. This case demonstrates how insufficient skin biopsy can have significant clinical consequences. Biopsy of the right neck only would have overlooked a DFSP and incorrectly given the patient a diagnosis of MF.

Maximizing diagnostic outcomes of skin biopsy specimens

Skin biopsy is a common dermatologic procedure that is typically required to assess cutaneous neoplasms and to evaluate indistinct skin eruptions for which a clinical differential diagnosis is considered. Although plenty of literature exists on the histopathologic features of different skin diseases, clues and methods that help maximize the diagnostic results and avoid common pitfalls in the processing of skin biopsies have received little attention. In cutaneous biopsy, interpretation is very important, as is the process of choosing the appropriate biopsy technique. As soon as the decision to perform a skin biopsy is taken and until microscopic slide evaluation occurs, multiple opportunities for error may arise, any of which may disadvantage the pathologist in efforts to reach a definitive diagnosis. Therefore, it is exceptionally important that clinicians work closely with pathologists to optimize biopsy results. The purpose of this review is to increase awareness of the potential for error in the course of obtaining and interpreting biopsy specimens. The process consists of several steps that refer to, respectively: choice of biopsy site; choice of technique; tissue fixation; tissue processing; the pathologist's interpretation; and clinicopathologic correlation. Avoiding these pitfalls may, in turn, maximize the pathologist's ability to make the correct diagnosis and thus provide better patient care.

AAD/ACMS/ASDSA/ASMS 2012 appropriate use criteria for Mohs micrographic surgery: a report of the American Academy of Dermatology, American College of Mohs Surgery, American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery

The appropriate use criteria process synthesizes evidence-based medicine, clinical practice experience, and expert judgment. The American Academy of Dermatology in collaboration with the American College of Mohs Surgery, the American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery has developed appropriate use criteria for 270 scenarios for which Mohs micrographic surgery (MMS) is frequently considered based on tumor and patient characteristics. This document reflects the rating of appropriateness of MMS for each of these clinical scenarios by a ratings panel in a process based on the appropriateness method developed by the RAND Corp (Santa Monica, CA)/University of California-Los Angeles (RAND/UCLA). At the conclusion of the rating process, consensus was reached for all 270 (100%) scenarios by the Ratings Panel, with 200 (74.07%) deemed as appropriate, 24 (8.89%) as uncertain, and 46 (17.04%) as inappropriate. For the 69 basal cell carcinoma scenarios, 53 were deemed appropriate, 6 uncertain, and 10 inappropriate. For the 143 squamous cell carcinoma scenarios, 102 were deemed appropriate, 7 uncertain, and 34 inappropriate. For the 12 lentigo maligna and melanoma in situ scenarios, 10 were deemed appropriate, 2 uncertain, and 0 inappropriate. For the 46 rare cutaneous malignancies scenarios, 35 were deemed appropriate, 9 uncertain, and 2 inappropriate. These appropriate use criteria have the potential to impact health care delivery, reimbursement policy, and physician decision making on patient selection for MMS, and aim to optimize the use of MMS for scenarios in which the expected clinical benefit is anticipated to be the greatest. In addition, recognition of those scenarios rated as uncertain facilitates an understanding of areas that would benefit from further research. Each clinical scenario identified in this document is crafted for the average patient and not the exception. Thus, the ultimate decision regarding the appropriateness of MMS should be determined by the expertise and clinical experience of the physician.

Skin biopsy for inflammatory and common neoplastic skin diseases: optimum time, best location and preferred techniques. A critical review

The diagnosis of skin diseases, particularly inflammatory dermatoses, is based primarily on clinical information. Pathologic examination of the biopsied specimen often serves as a complementary or confirmative part of the diagnosis. However, the clinical diagnosis of skin diseases may be challenging, as the clinical information and appearance of skin lesions invariably overlap. Evidence for a correct diagnosis may be lacking without histopathologic examination of skin biopsies. It is well known that the histologic diagnosis of inflammatory and other skin diseases requires clinicopathologic correlation, and there is evolution of skin lesions into different stages as the diseases progress. Other factors important for accurate dermatopathologic diagnosis are optimum time, best location and preferred techniques of skin biopsy. In searching for available information concerning when, where and how to take skin biopsies, it is noted that there are only limited practical guidelines currently available. We present this review article in hopes that our collective dermatopathologic and dermatologic experience can provide a quick reference for accurate diagnosis and proper management of skin diseases.