The distribution of cutaneous metastases correlates with local immunologic milieu

Cutaneous involvement in Ph-negative myeloproliferative neoplasms: from extramedullary hematopoiesis to myeloid metastasis with histiocytic differentiation. A systematic review of the literature

Myeloid neoplasms may metastasize to the skin, presenting a wide range of clinical-pathological features that often lead to a reduction in patients' survival. The presentation varies depending on the category of myeloid neoplasm and its prognostic significance. The literature has specifically focused on the features of acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), and chronic myelomonocytic leukemia (CMML). In this article, we aimed to uncover the peculiarities of clonal skin proliferations in the course of Ph-negative myeloproliferative neoplasms (MPNs). We conducted a systematic review and statistical analysis of the literature data. MPN patients mainly exhibited cutaneous extramedullary hematopoiesis, while a minority displayed cutaneous histiocytic lesions. Furthermore, these patients showed lower survival rates compared to the median survival of MPN patients, especially when calculating survival from the appearance of cutaneous lesions. Our work highlights, for the first time, the prognostic relevance and histological heterogeneity of cutaneous lesions in MPN. Moreover, it emphasizes the importance of dermatological and histological examinations when cutaneous lesions are present.

Clinical and Histopathologic Profile of Patients with Cutaneous Metastasis in a Tertiary Hospital in the Philippines

INTRODUCTION

Cutaneous metastases represent 2% of skin tumors, with an overall incidence of 5.3%. Although rare, clinical presentations of cutaneous metastasis vary and can be mistaken for benign and malignant skin conditions.

METHODOLOGY

This was a descriptive, retrospective review of all patients diagnosed with cutaneous metastasis seen at the Department of Dermatology from January 2013 to December 2019. Clinical and histopathologic data from the patients were collated from medical records, and slides were retrieved for review.

RESULTS

A total of 115 patients were included and 122 slides reviewed. There were more female than males, the mean age was 52.3 ± 14.0 years of age. The most common primary cancer was the breast, and accordingly, the most common location was anterior chest. Among the 122 slides reviewed from 104 patients, the most common histologic type was adenocarcinoma (72.1%), and showed the infiltrative pattern (26.2%). Other histologic types seen were melanoma (13.1%), leukemic infiltrates (11.5%), squamous origin (2.5%), and epithelioid sarcoma (0.8%). Lymphovascular invasion and dermal sclerosis were observed. Immunohistochemical stains were performed in only 13.9% of the cases. There was a high concurrence of the clinical with the histopathologic diagnosis (95.6%).

CONCLUSION

Although rare, patients with cutaneous metastasis may present in dermatology clinics. Knowledge of clinical features and low threshold for doing biopsies may prove useful for these patients. Similarly, dermatopathologists should be able to recognize histologic features of cutaneous metastasis morphologically. Histologic features may be subtle and may be reminiscent of benign inflammatory conditions, hence judicious use of immunohistochemical staining is recommended.

Skin immunity: dissecting the complex biology of our body's outer barrier

Our skin contributes critically to health via its role as a barrier tissue, carefully regulating passage of key substrates while also providing defense against exogenous threats. Immunological processes are integral to almost every skin function and paramount to our ability to live symbiotically with skin commensal microbes and other environmental stimuli. While many parallels can be drawn to immunobiology at other mucosal sites, skin immunity demonstrates unique features that relate to its distinct topography, chemical composition and microbial ecology. Here we provide an overview of skin as an immune organ, with reference to the broader context of mucosal immunology. We review paradigms of innate as well as adaptive immune function and highlight how skin-specific structures such as hair follicles and sebaceous glands interact and contribute to these processes. Finally, we highlight for the mucosal immunology community a few emerging areas of interest for the skin immunity field moving forward.

Tissue-specific Tregs in cancer metastasis: opportunities for precision immunotherapy

Decades of advancements in immuno-oncology have enabled the development of current immunotherapies, which provide long-term treatment responses in certain metastatic cancer patients. However, cures remain infrequent, and most patients ultimately succumb to treatment-refractory metastatic disease. Recent insights suggest that tumors at certain organ sites exhibit distinctive response patterns to immunotherapy and can even reduce antitumor immunity within anatomically distant tumors, suggesting the activation of tissue-specific immune tolerogenic mechanisms in some cases of therapy resistance. Specialized immune cells known as regulatory T cells (Tregs) are present within all tissues in the body and coordinate the suppression of excessive immune activation to curb autoimmunity and maintain immune homeostasis. Despite the high volume of research on Tregs, the findings have failed to reconcile tissue-specific Treg functions in organs, such as tolerance, tissue repair, and regeneration, with their suppression of local and systemic tumor immunity in the context of immunotherapy resistance. To improve the understanding of how the tissue-specific functions of Tregs impact cancer immunotherapy, we review the specialized role of Tregs in clinically common and challenging organ sites of cancer metastasis, highlight research that describes Treg impacts on tissue-specific and systemic immune regulation in the context of immunotherapy, and summarize ongoing work reporting clinically feasible strategies that combine the specific targeting of Tregs with systemic cancer immunotherapy. Improved knowledge of Tregs in the framework of their tissue-specific biology and clinical sites of organ metastasis will enable more precise targeting of immunotherapy and have profound implications for treating patients with metastatic cancer.

Cutaneous Metastases of Solid Tumors: Demographic, Clinical, and Survival Characteristics

BACKGROUND

Cutaneous metastasis (CM), while uncommon, is usually an indicator of poor prognosis. With cancer patients living longer, the incidence of CM has increased, which justifies its analysis.

OBJECTIVES

The objective of this study was to carry out a descriptive study of CM diagnosed for 18 years in a dermatology department of a tertiary care hospital and to assess the epidemiological, clinical, and histological variables that condition them, as well as data on their survival and prognosis.

METHODS

We performed a descriptive study of cases of CM diagnosed over 18 years in the dermatology department of a tertiary referral hospital analyzing the following variables: patient age and sex, site of primary neoplasm, pathochronology, survival time, histological findings, immunohistochemical markers, the anatomical area affected, the clinical appearance of the metastasis, therapeutic plan, and existence of metastases in other regions. We checked normal distribution using the Kolmogorov-Smirnov test and then compared the quantitative variables using the Student's t-test (unpaired samples), Mann-Whitney test (non-normal distribution), analysis of variance (ANOVA; for more than two groups), and categorical variables using the chi-square or Fisher's exact test.

RESULTS

We included 37 cases (20 men and 17 women), of whom 32 had died. The mean age was 62 ± 15 years. CM detection was defined early in 8% of cases, synchronous in 32%, and metachronous in 60%. The most frequent primary tumor sites were lungs (24%), breasts (21%), and bladders (11%). Most metastases were solitary. The most frequent locations for CM were the scalp, trunk, armpits, and groin. Most lesions had a nodular presentation (81%). Squamous cell carcinoma and adenocarcinoma showed the same frequency in lung cancer CM. Breast cancer leading to CM was the most common invasive ductal carcinoma. The most aggressive cases, with the worst survival, originated in lung neoplasms. Therapeutic management for most patients involved surgery in combination with other procedures. The only difference detected between the lung and breast cancer CM was the predominance of lung tumors in men (89%) and breast tumors in women compared with metastases from other sites; breast cancer CM manifested more frequently as plaques and less frequently as nodules (p < 0.05) and was less frequently associated with multisystemic metastasis. In lung cancer CM, time from tumor diagnosis to CM occurrence was shorter (p < 0.01) and multisystemic metastasis was more frequent than in CM of other tumors.

CONCLUSIONS

CM tends to affect patients aged above 60 years and arises predominantly from lung cancer in men and breast cancer in women. The most typical locations are the chest and scalp, and the appearance is usually nodular. Survival after CM detection is low, particularly in lung cancer CM.

Histopathologic and molecular profiling of lung adenocarcinoma skin metastases reveals specific features

AIMS

Little is known regarding the histopathological and molecular features of lung adenocarcinoma skin metastases. Our study is the largest to comprehensively explore these to date.

METHODS AND RESULTS

We performed a retrospective cohort study analysing 42 lung adenocarcinoma skin metastasis samples obtained from a database of 2659 lung adenocarcinomas collected between 2010 to 2020. EGFR exon 19 deletion was detected in one patient, and KRAS mutations were detected in 12 (33.3%) patients. The PD-L1 tumour proportion score was <1% in 27 patients, ≥1% and <50% in 8 patients, ≥50% in 6 patients, and not assessable in one patient. We showed that the predominant histopathologic subtype is different from that at other metastatic sites (p=0.024). TTF-1 was more often negative in skin metastases compared to other sites (p<0.001). The EGFR mutation rate tended to be lower for skin metastases compared to other sites (p=0.079). Skin metastases were associated with a high rate of PD-L1-negative cases (p=0.022).

CONCLUSION

Our work shows that the skin metastases of lung adenocarcinoma have a specific histopathologic profile.

Scalp Lesions Referred For Surgical Procedures: Single-Center 5-year Experience in Southwestern Poland

BACKGROUND/AIM

The head is a body site with a particular predisposition to skin malignancies due to exposure to UV radiation. The aim of the study was to better elucidate the characteristics of skin lesions that develop on the scalp.

PATIENTS AND METHODS

A retrospective review of all excised and histologically assessed lesions of the scalp at a single dermatosurgery unit throughout a five-year period was performed. Demographic features and lesion characteristics were compiled and analyzed.

RESULTS

Among 5,601 procedures during the analyzed period, 293 were performed on lesions on the scalp area (5.2%) with a mean patient age of 66±19.7 years. The defects were closed, mainly using primary closure, followed by skin grafts, and, least often, flaps (65.1%, 28.5%, 4.9%, respectively). Two thirds of the excised scalp lesions were histologically confirmed as malignant scalp tumors (mostly basal cell carcinomas followed by squamous cell carcinomas).

CONCLUSION

The vast majority of scalp lesions referred for surgical procedures appeared to be malignant. Therefore, dermatologists should pay special attention to the scalp by examining it thoroughly, as the lesions may be hidden by hair.

Multimodality imaging and treatment strategy for malignant scalp neoplasms in adults

Malignant scalp masses deserve much attention as they have the potential to destroy local structures, recur and metastasize to distant organs. Moreover, malignant scalp lesions are known to be more aggressive in behavior than their counterparts elsewhere in the body. Multimodality imaging is essential in narrowing the differential diagnoses of scalp masses, as well as in differentiating benign from malignant masses. Furthermore, imaging is important in (1) evaluating the extent of tumor invasion in the scalp, (2) staging the disease, (3) guiding surgical biopsy and/or resection of the tumor, (4) preoperative planning and post-treatment surveillance of scalp tumors. An interdisciplinary treatment approach is crucial for the management of scalp malignancies given their complex and aggressive nature. This review seeks to describe the unique clinical and imaging characteristics of various types of malignant scalp masses, as well as to review their current treatment strategies.

Developing Human Skin Contains Lymphocytes Demonstrating a Memory Signature

Lymphocytes in barrier tissues play critical roles in host defense and homeostasis. These cells take up residence in tissues during defined developmental windows, when they may demonstrate distinct phenotypes and functions. Here, we utilized mass and flow cytometry to elucidate early features of human skin immunity. Although most conventional αβ T (Tconv) cells in fetal skin have a naive, proliferative phenotype, a subset of CD4⁺ Tconv and CD8⁺ cells demonstrate memory-like features and a propensity for interferon (IFN)γ production. Skin regulatory T cells dynamically accumulate over the second trimester in temporal and regional association with hair follicle development. These fetal skin regulatory T cells (Tregs) demonstrate an effector memory phenotype while differing from their adult counterparts in expression of key effector molecules. Thus, we identify features of prenatal skin lymphocytes that may have key implications for understanding antigen and allergen encounters in utero and in infancy.

CyTOF reveals a complex lymphocyte landscape in developing human skin

Developing skin contains CD45RO⁺ conventional T cells with propensity to produce IFNγ

Regulatory T cells (Tregs) in skin before birth display effector memory properties

Skin Tregs increase in conjunction with initial hair follicle morphogenesis

Cutaneous Scalp Metastases of Malignant Phyllodes Tumor of the Breast

Phyllodes tumor (PT) of the breast is a relatively rare fibroepithelial tumor that accounts for < 1% of primary breast neoplasms. PT is classified histologically as benign, borderline, or malignant, and a malignant PT has greater potential to metastasize than benign PT. Although almost all other organs can be affected, common metastatic sites are the lung and bone via the hematogenous route. There have been several studies reporting cutaneous and soft tissue metastases of PT, though the incidence is rare. Herein, we report a very rare case of scalp metastasis of malignant PT that was diagnosed via skin biopsy and surgical excision.

A clinical, pathological and immunohistochemical series of 9 cases of primary cutaneous apocrine carcinomas of the head and neck

BACKGROUND/OBJECTIVES

Primary cutaneous apocrine carcinoma is a rare malignant adnexal skin tumour that can recur locally, spread to regional lymph nodes and metastatize to visceral organs. Wide dissemination and death from disease are much less common. The axilla is the most common site of presentation. It is infrequently reported in the head and neck region.

METHODS

All cases diagnosed as primary cutaneous apocrine carcinoma of the head and neck were retrospectively collected from the archives of the Division of Pathological Anatomy, University of Florence from 1996 to 2016. There was no history or clinical evidence of breast cancer. Clinical data and follow-up were collected by the clinicians.

RESULTS

Nine cases were found, with a mean age of 76 years, ranging in size between 0.3 and 3.5 cm. Clinically, they were frequently mistaken for basal cell carcinomas. Histopathologically, all the tumours showed decapitation secretion, a tubular, solid or mixed (tubulo-papillary and solid-tubular) growth pattern and were predominantly classified as grade 2 tumours. GCDFP-15 and hormone receptors were variably expressed. HER2 and podoplanin were negative in all cases. In one case, spreading to regional lymph nodes was observed. No cases were associated with death due to the disease.

CONCLUSION

As immunohistochemical analysis lacks specificity in distinguishing primary cutaneous apocrine carcinoma from a cutaneous metastasis of breast carcinoma, detailed clinical history, breast examination, adequate treatment and follow-up are necessary to confirm a diagnosis of primary cutaneous apocrine carcinoma.

Analysis of Judicial Precedents Cases Regarding Skin Cancer from 1997 to 2017 in Republic of Korea

Background

Both medical disputes and the incidence of skin cancer are increasing in Korea.

Objective

The aim of this study was to figure out the medical litigation related to skin cancer and propose a method to prevent the medical disputes.

Methods

Skin cancer-related judgments were searched by The Supreme Court of Korea's Written Judgment Management System based on the keywords for skin cancer. The search system included sentenced cases at the Lower Courts, the Appellate Courts, and the Supreme Court from 1997 to 2017.

Results

Seven cases were selected as the litigation cases related to skin cancer. Four cases (57.1%) presented malignant melanoma, while the rest presented squamous cell carcinoma, metastatic skin cancer, and peripheral T cell lymphoma (1 case in each). Four cases resulted in death from cancer metastasis, and 3 cases presented as sequelae. The legal issues related to the medical disputes could be categorized as follows: misdiagnosis, delayed diagnosis, performance error, and lack of informed consent. Delayed diagnosis and lack of informed consent were the most common issues (n=4) in the precedents. Five cases (71.4%) were sentenced the awarded amounts to the plaintiff, including 2 cases of settlement decision. The average awarded amount was 42,553,644±27,567,455 Korean won.

Conclusion

Physicians should pay attention to the cases of the skin cancer to prevent medical malpractice and disputes. The practices pertaining to proper diagnosis, treatment plans, and obtaining an informed consent should be followed during the course of treating skin cancer.

A retrospective cohort study of melanoma prevalence stratified by body site in a Regional Australian Population 1994-2017: Site-specific protective mechanisms

BACKGROUND

Australia has the highest incidence of cutaneous melanoma worldwide. Previous studies have identified some body areas (forearms and dorsal hands) have lower rates of melanoma than expected when compared with other similarly exposed areas, leading to the suggestion that endogenous immunological protective mechanisms in certain body sites may exist.

AIMS AND METHODS

We hypothesise that examination of melanoma by body site in a regional Australian setting would demonstrate no significant variation in the incidence of melanoma across highly sun exposed areas including the head and neck and upper limbs. Results were stratified by body site and further examined by univariate correlation analysis by gender, age, body site, Breslow thickness and subtype. Polytomous logistic regression was used to test the difference in risk factors by location of melanoma.

RESULTS

A total of 772 melanomas were included in the analysis. Melanomas of the upper limb were more likely to affect females (OR = 2.415 95%CI: 1.433-4.072) and more likely to be thinner than other body sites. Compared to other international studies, statistically significant decreased rates of melanoma were seen on the upper limb compared to other areas of the body (X²  = 16.29, P < 0.001). Examination of sites of melanoma on the upper limb showed significantly decreased rate on the distal upper limb given relative body surface areas (X²  = 6.30 P = 0.04).

DISCUSSION AND CONCLUSIONS

Our study was limited by its retrospective nature, and the findings require validation in a larger prospective cohort. Further exploration of such mechanisms may lead to new insights into the immunological mechanisms surrounding cutaneous melanoma.

Concurrent metastases of papillary thyroid carcinoma to the scalp and Meckel's cave

We present the case of a 65-year-old man with severe headaches and unilateral facial weakness, seen in consultation by the dermatology service to rule out primary cutaneous melanoma after brain imaging identified an enlarging mass within the right trigeminal (Meckel's) cave. Examination revealed only a pair of erythematous papules on the scalp, for which biopsy demonstrated metastatic papillary thyroid carcinoma. Further evaluation and subsequent thyroidectomy confirmed the origin of widespread internal disease, followed by definitive excision of scalp lesions and multimodal management of systemic involvement. Whereas presentation of metastasis to the skin is highly variable, a low threshold for biopsy may allow for histological identification of internal disease not otherwise considered in the clinical differential.

Prognostic factors in head and neck melanoma according to facial aesthetic units

BACKGROUND

Head and neck melanoma is a clinical challenge. Indeed, cutaneous head and neck melanoma shows a worse prognosis in comparison to melanomas of other body sites. Although the emphasis on facial cosmetic preservation plays a pivotal role in comparison to other body areas, specific Facial Aesthetic Units (FAU) could also play a key role in the prognostic evaluation of the malignancy.

METHODS

The aim of the current study was to evaluate the general outcome and clinicopathological features of head and neck melanoma and to detect prognostic differences according to each FAU. The Kaplan-Meier product was used to calculate survival curves, while Cox proportional-hazard regression was performed to evaluate the predictive value of each FAU.

RESULTS

A total of 221 head and neck melanoma patients was included in our analysis. In the nasal FAU, we found a high rate of local recurrence, which affected significantly disease-free survival. The worse prognosis was observed in melanoma of the scalp, which showed a greater tendency to skip metastases in internal organs. Moreover, we found that scalp showed a low incidence of non-melanoma skin cancers, if compared to other FAU, highlighting that the scalp local milieu might play a more prominent role in melanoma biology than chronic UV exposition.

CONCLUSIONS

Although FAUs have an aesthetic function, they could also play a role in the evaluation and follow-up of melanoma.

Transcriptional landscape of epithelial and immune cell populations revealed through FACS-seq of healthy human skin

Human skin consists of multiple cell types, including epithelial, immune, and stromal cells. Transcriptomic analyses have previously been performed from bulk skin samples or from epithelial and immune cells expanded in cell culture. However, transcriptomic analysis of bulk skin tends to drown out expression signals from relatively rare cells while cell culture methods may significantly alter cellular phenotypes and gene expression profiles. To identify distinct transcriptomic profiles of multiple cell populations without substantially altering cell phenotypes, we employed a fluorescence activated cell sorting method to isolate keratinocytes, dendritic cells, CD4+ T effector cells, and CD8+ T effector cells from healthy skin samples, followed by RNA-seq of each cell population. Principal components analysis revealed distinct clustering of cell types across samples, while differential expression and coexpression network analyses revealed transcriptional profiles of individual cell populations distinct from bulk skin, most strikingly in the least abundant CD8+ T effector population. Our work provides a high resolution view of cutaneous cellular gene expression and suggests that transcriptomic profiling of bulk skin may inadequately capture the contribution of less abundant cell types.

Sebaceous Gland-Rich Skin Is Characterized by TSLP Expression and Distinct Immune Surveillance Which Is Disturbed in Rosacea

The microbial community exhibits remarkable diversity on topographically distinct skin regions, which may be accompanied by differences in skin immune characteristics. Our aim was to compare the immune milieu of healthy sebaceous gland-rich (SGR) and sebaceous gland-poor skin areas, and to analyze its changes in an inflammatory disease of SGR skin. For this purpose, immunohistochemical, immunocytochemical, and quantitative real-time PCR analyses of thymic stromal lymphopoietin (TSLP) and other cytokines, phenotypic immune cell markers and transcription factors were carried out in samples from sebaceous gland-poor, SGR skin and from papulopustular rosacea. TSLP mRNA and protein production was also studied in cultured keratinocytes. In SGR skin, higher TSLP expression, dendritic cell appearance without prominent activation, and T cell presence with IL-17/IL-10 cytokine milieu were detected compared with sebaceous gland-poor skin. Linoleic acid, a major sebum component, was found to induce TSLP expression dose-dependently in keratinocytes. In papulopustular rosacea, significantly decreased TSLP level and influx of inflammatory dendritic cells and T cells with IL-17/interferon-γ cytokine milieu were observed. According to our results, SGR skin is characterized by a distinct, noninflammatory immune surveillance, which may explain the preferred localization of inflammatory skin diseases, and can influence future barrier repair therapeutic concepts.