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

Malignant wound aetiology, diagnosis and management: a case series and literature review

OBJECTIVE

Malignant wounds develop when neoplastic cells invade the skin either locally or by lymphatic and haematogenous spread. They can present as hard-to-heal wounds and underlying causes include: primary skin cancer; metastasis of extracutaneous primary malignancy; malignant transformation of a hard-to-heal wound; iatrogenic injury; and cutaneous forms of cancers of non-skin origin. High clinical suspicion for a malignant wound should be confirmed with skin biopsy. The aim of this case series is to highlight a combination of both clinically clear cutaneous malignancies and not-so-obvious wounds caused by malignancy.

METHOD

This case series examines patients with malignant wounds of varying aetiology and appearance. For each case, we explain the pathophysiology, atypical features, diagnostic approach and treatment. We also discuss types of wound biopsy and general wound management principles.

RESULTS

Among the 11 cases analysed using descriptive statistics, median wound duration before presentation at our clinic was one year, while median age at presentation was 65 years. Our case series included the following diagnoses: cutaneous metastasis of invasive ductal carcinoma of the breast (n=2); cutaneous metastasis of colorectal adenocarcinoma (n=1); Marjolin's ulcer (n=1), basal cell carcinoma (BCC) (n=2), primary cutaneous squamous cell carcinoma (SCC) (n=1), metastatic malignant melanoma (n=1), cutaneous T-cell lymphoma (n=1), cutaneous angiosarcoma (n=1), Kaposi sarcoma (n=1) and recurrent tonsillar SCC with osteoradionecrosis (n=1); one case had both BCC and SCC.

CONCLUSION

Punch and excisional biopsies were the most frequently used diagnostic techniques. Local wound therapy addressed bleeding, malodour, exudate, pain and infection. However, wound healing is usually achieved once the underlying malignancy is treated. In advanced or metastatic disease, palliative wound care aims to prevent exacerbation of existing wounds and focuses on patient comfort.

Clinical-pathologic correlation: The impact of grossing at the bedside

The unenlightened clinician may submit a skin specimen to the lab and expect an "answer." The experienced clinician knows that in performing skin biopsies, it is critical to select the most appropriate: 1) anatomic location for the biopsy1,2; 2) type of biopsy1,2; 3) depth and breadth of the biopsy; and 4) medium for hematoxylin and eosin staining (formalin) or direct immunofluorescence (Michel's Transport Medium or normal saline).2 Demographic information, anatomic location, clinical context, and differential diagnosis are all critical components of a properly completed requisition form.3-5 Proper biopsy design and appropriate grossing of the tissue at the bedside should be added to this list. In this article, we review the basics of gross pathologic examination and then provide four examples to demonstrate that optimal clinical-pathologic correlation requires the clinician consider the needs of the pathologist when tissue is presented to the lab.

Cytokine/Chemokine assessment as a complementary diagnostic tool for inflammatory skin diseases

Inflammatory skin conditions are the 4th leading cause of non-fatal health burden in the general population worldwide. The diagnosis of skin lesions due to systemic drug reactions, viral or bacterial exanthems, or in patients with psoriasis, atopic dermatitis or contact dermatitis is often difficult and relies heavily upon conventional histopathologic examination. Conversely, it is widely accepted that the cutaneous profile of inflammatory markers, or 'inflammatory signature', is differentially expressed in various skin conditions. In this pilot study, we investigated the possibility of inflammatory skin disease diagnosis from an immunological perspective in small punch biopsies. We collected lesional and perilesional punch biopsies from 139 patients suffering from a variety of inflammatory skin conditions and attending the Dermatology Department at the Princess Alexandra Hospital in Brisbane, Australia. Using bead-based immunoassays we were able to measure 13 out of 17 inflammatory markers from a pre-selected multi-analyte panel and to detect significant differences between lesional and perilesional biopsies from each individual patient. Hierarchical and unbiased clustering methods based on inflammatory signatures grouped psoriasis and atopic dermatitis lesions into individual clusters in contrast to other skin conditions, highlighting the potential of inflammatory signatures to be used as diagnostic differentiators and to inform alternative targets in anti-inflammatory treatment strategies.

A case series and literature review of necrobiosis lipoidica

Summary

Necrobiosis lipoidica (NL) is a rare and chronic disease characterised by yellow-brown, atrophic, telangiectatic plaques usually located on the lower extremities, with pathological features of collagen necrobiosis and dermal inflammation. Most cases are seen in those with diabetes mellitus, particularly type 1 diabetes (T1DM), and many without diabetes have evidence of abnormal glucose tolerance or family history of autoimmune disease. In this study, we describe four patients with NL and T1DM. A common theme is late identification and delay in diagnosis. Hence, we discuss the clinical features, need for clinicopathological correlation, and the management and prognostic implications for this distinctive entity. While most remain relatively asymptomatic, others progress to debilitating disease with pruritus, dysesthesia, and pain. Pain is often intense in the presence of ulcerated plaques, a morbid complication of NL. Diagnosis requires the integration of both clinical and histopathological findings. NL has proven a challenging condition to treat, and despite the numerous therapeutic modalities available, there is no standard of care. Hence, in this study, we provide an overview of current management strategies available for NL.

Learning points

Necrobiosis lipoidica (NL) is classically seen in patients with type 1 diabetes. Koebner phenomenon, defined as the appearance of new skin lesions on previously unaffected skin secondary to trauma, is a well-recognised feature in NL. Background skin phototype contributes to variable yellow appearance of lesions in NL. Diagnosis of NL requires careful clinicopathological correlation. NL is a chronic disease often refractory to treatment leading to significant morbidity for the patient and a management conundrum for the multidisciplinary healthcare team. No standard therapeutic regimen has been established for the management of NL.

Skin Biopsy Techniques

Because many skin lesions and disorders can appear similar, primary care clinicians often struggle to diagnose them definitively without histopathologic information obtained from a biopsy. This review article explains how to decide whether a lesion should be biopsied and what type of biopsy technique to use and then outlines the stepwise approach to each of the most common skin biopsy techniques: shave, saucerization, punch, fusiform, and subcutaneous nodule biopsies. Finally, potential pitfalls and complications are discussed so the clinician can avoid those and can provide a cosmetically acceptable result from these common outpatient procedures.

Tape Stripping: Investigational, Diagnostic and Therapeutic Uses in Dermatology

Adhesive tape has been used in the scientific study of human skin for over 90 years. Using the tape stripping method in dermatology has aided in the research and diagnose of different skin diseases. Basic science, identification, and therapeutic interventions in skin diseases such as psoriasis, atopic dermatitis, non-melanoma skin cancer, and melanoma have been studied using this technique. Among many promising applications that will be discussed throughout this paper, the Pigmented Lesion Assay (PLA) will be discussed in depth in relation to melanoma. This product carries considerable and significant research towards early detection of melanoma. Tape stripping is unique and advantageous in its ability to provide a non-surgical approach to evaluating the human epidermis. The cellular and molecular components of the skin are used to diagnose different skin conditions without invasive skin biopsy.

Non-invasive monitoring of skin inflammation using an oxygen-sensing paint-on bandage

Inflammation involves a cascade of cellular and molecular mediators that ultimately lead to the infiltration of immune cells into the affected area. This inflammatory process in skin is common to many diseases including acne, infection, and psoriasis, with the presence or absence of immune cells a potential diagnostic marker. Here we show that skin inflammation can be non-invasively measured and mapped using a paint-on oxygen sensing bandage in an in vivo porcine inflammation model. After injection of a known inflammatory agent, the bandage could track the increase, plateau, and decrease in oxygen consumption at the injury site over 7 weeks, as well as discern inflammation resultant from injection at various depths beneath the surface of the skin. Both the initial rate of pO₂ change and the change in bandage pO₂ at equilibration (CBP₂₀) were found to be directly related to the metabolic oxygen consumption rate of the tissue in contact. Healthy skin demonstrated an initial pO₂ decrease rate of 6.5 [Formula: see text], and CBP₂₀ of 84 [Formula: see text]. Inflamed skin had a significantly higher initial consumption rate of 55 [Formula: see text], and a larger CBP₂₀ of 140 [Formula: see text]. The change in the bandage pO₂ before and after equilibration with tissue was found to correlate well with histological evidence of skin inflammation in the animals.

Testing of viable human skin cell dilution cultures as an approach to validating microsampling

Skin biopsies are a valuable technique in the diagnosis of cutaneous inflammatory and neoplastic conditions. We were interested to test the minimal size or equivalent volume by dilution of proteolytically disassociated skin tissue required to allow the isolation and propagation of cutaneous cells, for freezing, storage and biochemical analysis. It was possible to propagate with 100% efficiency fibroblast and melanocytic cells from a 0.1 to 0.5 mm³ equivalent neonatal foreskin sample using a combination of DispaseII and CollagenaseIV. The smallest tissue dilution that allowed melanocytic cell culture was 0.01 mm³, which equated to approximately 16 cells based on the average skin density of melanocytes. However, passaging of cells to create frozen stocks was achieved routinely only from 1 mm³ skin, equating to 1560 cells. Tissue-specific antigen expression of these cultures was tested by western blot of total protein extracts. There was no pigmentation antigen expression in fibroblast cultures; however, smooth muscle actin protein expression was high in fibroblast but absent from melanocytic cell strains. Melanocytic cells expressed pigmentation antigens and E-cadherin, but these were not detected in fibroblasts. Moreover, maturation of these melanocytic cells resulted in a decrease of Dopachrome Tautomerase antigen expression and induction of Tyrosinase protein consistent with the differentiation potential seen in cell cultures derived routinely from large sections of skin tissue.

Skin Biopsy, the Allergists' Tool: How to Interpret a Report

Inflammatory dermatoses are frequently encountered by the allergist, and histologic evaluation achieved through skin biopsy can be of tremendous value clinically. There is no substitute for a thorough history and physical exam; however, the skin biopsy is a simple, in-office procedure with little risk of complication that can provide invaluable information when a diagnosis is uncertain. Histopathologically, many inflammatory eruptions can look similar or overlap, but information provided by the dermatopathologist can help the clinician render or refine the clinical diagnosis and guide management. This review will discuss descriptive elements contained in the pathology report to provide a framework that can be used by the allergist to comfortably and confidently diagnose inflammatory dermatologic conditions.

Ongoing epidemic of cutaneous leishmaniasis among Syrian refugees, Lebanon

In September 2012, a cutaneous leishmaniasis outbreak began among Syrian refugees in Lebanon. For 948 patients in whom leishmaniasis was not confirmed, we obtained samples for microscopic confirmation and molecular speciation. We identified Leishmania tropica in 85% and L. major in 15% of patients. After 3 months of megulamine antimonite therapy, patients initial cure rate was 82%.

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.

Microbiopsy engineered for minimally invasive and suture-free sub-millimetre skin sampling

We describe the development of a sub-millimetre skin punch biopsy device for minimally invasive and suture-free skin sampling for molecular diagnosis and research. Conventional skin punch biopsies range from 2-4 mm in diameter. Local anaesthesia is required and sutures are usually used to close the wound. Our microbiopsy is 0.50 mm wide and 0.20 mm thick. The microbiopsy device is fabricated from three stacked medical grade stainless steel plates tapered to a point and contains a chamber within the centre plate to collect the skin sample. We observed that the application of this device resulted in a 0.21 ± 0.04 mm wide puncture site in volunteer skin using reflectance confocal microscopy. Histological sections from microbiopsied skin revealed 0.22 ± 0.12 mm wide and 0.26 ± 0.09 mm deep puncture sites. Longitudinal observation in microbiopsied volunteers showed that the wound closed within 1 day and was not visible after 7 days. Reflectance confocal microscope images from these same sites showed the formation of a tiny crust that resolved by 3 weeks and was completely undetectable by the naked eye. The design parameters of the device were optimised for molecular analysis using sampled DNA mass as the primary end point in volunteer studies. Finally, total RNA was characterized. The optimised device extracted 5.9 ± 3.4 ng DNA and 9.0 ± 10.1 ng RNA. We foresee that minimally invasive molecular sampling will play an increasingly significant role in diagnostic dermatology and skin research.