Predictors of Local Invasion in Infiltrative Basal Cell Carcinoma: Tumour Budding Outperforms the WHO Subtyping.

Tumour budding (TB) correlates with increased local invasion in various neoplasms. Certain basal cell carcinomas (BCCs) exhibit local aggressiveness. Detecting adverse prognostic factors in partial biopsies could aid in identifying cases with heightened local risk. The absolute number of TB (≤ 3 tumour cells) in excision specimens of 271 infiltrative BCCs (0: absent; 1: 1-2 foci; 2: ≥ 3 foci; 3: ≥ 10 foci), the histopathological subtype and depth of infiltration, perineural invasion, and other histological features were evaluated. A significant correlation was found between TB and both depth of infiltration (rho 0.445, p < 0.001) and perineural invasion (p = 0.009). In the multivariate analysis of depth and perineural invasion (multiple regression, stepwise), TB was identified as a significant covariate together with diameter, inflammation, and perineural invasion for the former, and depth for the latter. Conversely, no correlation existed between the WHO histological subtypes (infiltrating, sclerosing, and micronodular), and depth of infiltration or perineural invasion. This study demonstrates the value of TB as a biomarker for local invasiveness in BCC. In routine practice, a count of ≥ 3 TB foci in lesions incompletely excised or with narrow tumour-free surgical margins would be a straightforward and reproducible method to guide BCC treatment.

Spanish cohort of VEXAS syndrome: clinical manifestations, outcome of treatments and novel evidences about UBA1 mosaicism.

BACKGROUND: The vacuoles, E1-enzyme, X linked, autoinflammatory and somatic (VEXAS) syndrome is an adult-onset autoinflammatory disease (AID) due to postzygotic UBA1 variants. OBJECTIVES: To investigate the presence of VEXAS syndrome among patients with adult-onset undiagnosed AID. Additional studies evaluated the mosaicism distribution and the circulating cytokines. METHODS: Gene analyses were performed by both Sanger and amplicon-based deep sequencing. Patients' data were collected from their medical charts. Cytokines were quantified by Luminex. RESULTS: Genetic analyses of enrolled patients (n=42) identified 30 patients carrying UBA1 pathogenic variants, with frequencies compatible for postzygotic variants. All patients were male individuals who presented with a late-onset disease (mean 67.5 years; median 67.0 years) characterised by cutaneous lesions (90%), fever (66.7%), pulmonary manifestations (66.7%) and arthritis (53.3%). Macrocytic anaemia and increased erythrocyte sedimentation rate and ferritin were the most relevant analytical abnormalities. Glucocorticoids ameliorated the inflammatory manifestations, but most patients became glucocorticoid-dependent. Positive responses were obtained when targeting the haematopoietic component of the disease with either decitabine or allogeneic haematopoietic stem cell transplantation. Additional analyses detected the UBA1 variants in both haematopoietic and non-haematopoietic tissues. Finally, analysis of circulating cytokines did not identify inflammatory mediators of the disease. CONCLUSION: Thirty patients with adult-onset AID were definitively diagnosed with VEXAS syndrome through genetic analyses. Despite minor interindividual differences, their main characteristics were in concordance with previous reports. We detected for the first time the UBA1 mosaicism in non-haematopoietic tissue, which questions the previous concept of myeloid-restricted mosaicism and may have conceptual consequences for the disease mechanisms.

Pancreatic panniculitis revisited: A series of 34 patients.

BACKGROUND: Pancreatic panniculitis is a rare form of panniculitis generally associated with acute or chronic pancreatitis, and less frequently with pancreatic carcinoma. Clinically, it presents with subcutaneous nodules usually located in the lower extremities, however, it presents an almost pathognomonic histopathological finding with enzymatic fat necrosis in the adipose tissue. METHODS: In this retrospective case series of five hospitals, biopsy specimens of cutaneous lesions of pancreatic panniculitis were reviewed. Clinical information was obtained through medical records. RESULTS: A total of 34 cases were included, 23 women and 11 men, aged between 31 and 92 years. The most common associated pancreatic disease was acute pancreatitis (23 cases) and its main triggering cause was gallstones (17 cases). In two patients it was related to chronic pancreatitis and six cases were associated with malignancy. Histopathological findings were always the key to diagnosis. In the biopsies reviewed, mostly lobular panniculitis with the characteristic necrosis of the adipocytes was observed. In addition, nine of the cases presented with Splendore-Hoeppli phenomenon. CONCLUSIONS: We present the largest series of pancreatic panniculitis. Clinically, the female predominance and biliary lithiasis as the main cause of acute pancreatitis are to be emphasized. Histopathologically, a peripheral eosinophilic striated rim surrounding aggregates of ghost adipocytes consistent with Splendore-Hoeppli is an additional clue to its diagnosis.

Adalimumab Biosimilar-Induced Autoimmunity-Related Sweet-Like Neutrophilic Dermatosis.

ABSTRACT: Antitumor necrosis factor therapies have shown to produce a broad range of cutaneous eruptions. We report the case of a patient under adalimumab biosimilar treatment for a punctate inner choroidopathy who developed a cutaneous eruption on sun-exposed areas that showed a diffuse dermal neutrophilic infiltrate consistent with a Sweet-like neutrophilic dermatosis and some features of autoimmunity.

Hemosiderotic Xanthelasmas. A New Clinicopathological Variant of Xanthelasma Palpebrarum or a Localized Variant of Xanthosiderohistiocytosis of the Eyelids?

ABSTRACT: Xanthelasma palpebrarum represent the most common subtype of cutaneous plane xanthomas. Xanthosiderohistiocytosis is considered a rare variant of xanthoma disseminatum, with only 4 cases reported to date. We report the case of a man with progressive pigmented lesions on the 4 eyelids that could correspond to hemosiderotic xanthelasmas or a localized variant of xanthosiderohistiocytosis.

Approach to the so-called "Invisible Dermatosis": When Subtle Histopathological Findings Guide Diagnosis.

ABSTRACT: Invisible dermatosis is a concept that can be applied either to clinical or histopathological findings. We will focus on the dermatopathological aspect of this invisible dermatosis that can be seen as dermatosis with subtle histopathological findings that are mandatory to known to stablish the diagnosis. With a proper approach facing in depth the different skin layers from stratum corneum to subcutaneous tissue combined with some especial stains, special investigations and mostly a proper clinicopathological correlation, the problem of missing out a diagnosis can be decreased. We will review the general aspects for diagnosis and the peculiar findings of an in-depth review of them because it is important to note that minor changes on a skin biopsy do not mean it is disease free. We will review classic clues, we will add some new useful ones, and we will also provide a guide on the special stains helpful, such as periodic acid-Schiff when facing fungi, orcein-Giemsa and van Gieson when altered elastic fibers are suspected, or Pearl and Masson Fontana when an altered skin pigmentation is suspected.

Alterations in p53, Microsatellite Stability and Lack of MUC5AC Expression as Molecular Features of Colorectal Carcinoma Associated with Inflammatory Bowel Disease.

Colitis-associated colorectal carcinoma (CAC) occurs in inflammatory bowel disease (IBD) because of the "chronic inflammation-dysplasia-cancer" carcinogenesis pathway characterized by p53 alterations in the early stages. Recently, gastric metaplasia (GM) has been described as the initial event of the serrated colorectal cancer (CRC) process, resulting from chronic stress on the colon mucosa. The aim of the study is to characterize CAC analyzing p53 alterations and microsatellite instability (MSI) to explore their relationship with GM using a series of CRC and the adjacent intestinal mucosa. Immunohistochemistry was performed to assess p53 alterations, MSI and MUC5AC expression as a surrogate for GM. The p53 mut-pattern was found in more than half of the CAC, most frequently stable (MSS) and MUC5AC negative. Only six tumors were unstable (MSI-H), being with p53 wt-pattern (p = 0.010) and MUC5AC positive (p = 0.005). MUC5AC staining was more frequently observed in intestinal mucosa, inflamed or with chronic changes, than in CAC, especially in those with p53 wt-pattern and MSS. Based on our results, we conclude that, as in the serrated pathway of CRC, in IBD GM occurs in inflamed mucosa, persists in those with chronic changes and disappears with the acquisition of p53 mutations.

Oral submucous fibrosis presenting with histopathological lichenoid changes as predominant feature: Report of five cases and review of the literature.

Oral submucous fibrosis (OSF) is a precancerous condition of the oral cavity associated with habitual chewing of quid, with a high incidence among populations of the Indian subcontinent and Southeast Asia. Clinically, its initial manifestation may mimic oral lichen planus or lichen sclerosus. If the habit is not halted, the mucosa gets leathery and thickened, and fibrous bands form causing significant morbidity. Microscopically, it is characterized by atrophic epithelium, loss of rete ridges, and hyalinization of lamina propria. Of note, these hallmark histopathological features may be overlooked in the unusual presence of lichenoid interface changes, which may lead to the wrong diagnosis. We present herein five cases in which the rare joint appearance of OSF and lichenoid reaction features posed a diagnostic challenge. Due to its progressive nature and malignant potential, the presence of oral lichenoid changes overlying submucous hyalinization, in the right clinical and demographic setting, should raise suspicion of OSF and prompt actions directed at quid-chewing discontinuation.

Acral Calcified Vascular Leiomyoma: Report of 3 Cases and Literature Review.

ABSTRACT: Angioleiomyomas are benign neoplasms, which usually present as solitary, slow-growing nodules on the skin of lower extremities, but acral location on the hands or feet is unusual. Yet, microscopically, they may show many histopathological variants, focal calcification is uncommon. Extensive calcification masquerading the real nature of the tumor has been rarely reported, the term acral calcified leiomyoma having been proposed for this entity. This change is more often in distal locations and has been interpreted as degenerative in nature, probably related to repetitive minor trauma. We report 3 examples of this unusual condition on the feet of 2 male and one female subjects (aged, 68, 69, and 80 years) and make a review of the 31 cases available in the literature. Two of our cases are associated with highly uncommon features, such as transepidermal calcium elimination and concomitant calcaneal spur.

Histopathologic Spectrum of Findings Associated With Tattoos: Multicenter Study Series of 230 Cases.

IMPORTANCE: Reactions to tattoo may simulate common dermatosis or skin neoplasms. Histopathology allows diagnosis and helps determining the level and degree of inflammation associated, consequently orientating treatment. OBJECTIVE: To describe the histological features found in biopsies of cutaneous reactions to tattoo. DESIGN: This study was designed as a multicenter case series. SETTING: All consecutive histopathological samples of tattoos referred from 1992 to 2019 to the Hospital General de Catalunya, Hospital Germans Trias i Pujol, and a private practice, all in Barcelona, Spain, and from the Kempf und Pfaltz Histologische Diagnostik in Zurich, Switzerland were retrieved from the files. PARTICIPANTS AND EXPOSURE: The inclusion criteria were all cosmetic/permanent makeup, artistic/professional, and traumatic tattoos associated with either inflammatory reactions alone and/or with tumors and/or infections. Exclusion criteria were cases without any associated pathologic finding in the place of the ink, amalgam tattoos, and medical or temporary tattoos. MAIN OUTCOMES AND MEASURES: In all patients, clinical features (age, sex, location, tattoo color, and presentation) were recorded. Histological features evaluated included ink color, associated tumors or infections, and inflammatory reaction pattern. Inflammation was graded in low to moderate or severe. RESULTS: From 477 biopsies diagnosed as tattoos, 230 cases from 226 patients met the inclusion criteria. Samples corresponded to 107 male and 120 female subjects and 3 of unknown gender. Median age was 39 years (ranging from 9 to 84 years). Fifty-three samples were referred from centers in Spain and 177 from the center in Switzerland. The series was analyzed in 2 parts: tattoos associated only with inflammatory reactions (117/230) and tattoos associated with tumors or infections (113/230). The most common form of inflammatory pattern associated with tattoo was the fibrosing reaction (79/117, 68%), followed by granulomatous reaction (56/117, 48%), lichenoid reaction (33/117, 28%), epithelial hyperplasia (28/117, 24%), pseudolymphoma (27/117, 23%) and spongiotic reaction (27/117, 23%). Combined features of 2 or more types of inflammatory patterns were seen in 64% cases. CONCLUSIONS AND RELEVANCE: Our series confirms that cutaneous reactions to tattoos are polymorphous. Inflammation tends to present with combined patterns. Infections are tending to decline, and pathologic findings are not specific to ink color or clinical features.

Adenoma of the nipple: a mimic of breast malignancy.

Adenoma of the nipple is a very uncommon benign neoplasm of lactiferous ducts. Its clinical presentation is variable and it can be easily misdiagnosed as a malignancy such as mammary Paget disease or breast intraductal carcinoma. Although dermoscopy and imaging tests such as ultrasonography or mammography can be of help, histological examination is mandatory to confirm the diagnosis. We describe the clinical, dermoscopic, and histopathological findings in a patient with nipple adenoma and discuss the clinical and histological differential diagnosis as well as the different treatment options.

The Role of Epithelial-to-Mesenchymal Transition in Cutaneous Squamous Cell Carcinoma : Epithelial-to-Mesenchymal Transition in Cutaneous SCC.

OPINION STATEMENT: The capacity of cells to modify their phenotypes from epithelial to mesenchymal (epithelial-to-mesenchymal transition or EMT) and vice versa provides them with a dynamic plasticity essential for human life, from embryogenesis to wound healing. Current knowledge about carcinogenetic mechanisms leaves little doubts on the pivotal participation of these interchangeable processes in cancer development, and their influence has been quite clearly established in the progression of cutaneous squamous cell carcinoma. A complex and ordered interplay of signals induces the shift between both phenotypes, providing cells with the most suitable state at every moment to face the next step in tumor invasion and dissemination. Some stimulatory triggers have opposite effects according to the biological context and in many cases exert collateral functions. This scenario makes finding an ideal therapeutic target difficult but provides the opportunity to intervene simultaneously at many different levels with small actions such as targeting the tumor environment. In any case, advances in knowledge of the EMT mechanisms and their influence on carcinogenesis and drug resistance will greatly influence the therapeutic strategies for many human tumors, including cutaneous squamous cell carcinoma.

Band-like Lipomatous Metaplasia of the Superficial Dermis and Nonseptate Subcutaneous Tissue: A Rare Histopathological Phenomenon With Ultrasonographic Correlation.

Lipomatous metaplasia of the upper dermis is a rare phenomenon scarcely described in the literature which has always been identified in the context of inflammatory or neoplastic processes. Microscopically, it should be distinguished from pseudolipomatosis cutis, dermal lipoma, nevus lipomatosus, and focal dermal hypoplasia (Goltz syndrome). This is the first report of the histologic and ultrasound evaluation of a patient with extensive involvement and the description of the coincidental finding of an anomalous nonseptate subcutaneous tissue.

Are there distinct clinical and pathological features distinguishing idiopathic from drug-induced subacute cutaneous lupus erythematosus? A European retrospective multicenter study.

BACKGROUND: Clinical and pathologic criteria to distinguish drug-induced subacute lupus erythematosus (DI-SCLE) from idiopathic (I-SCLE) are controversial. OBJECTIVE: The aim of the survey was a retrospective analysis of a consistent number of iatrogenous and idiopathic SCLE cases, by means of clinical and histopathologic investigation. METHODS: Eleven European university dermatology units collected all diagnosed cases from January 2000 to December 2016. Board-certified dermatopathologists reviewed the histopathologic specimens. Statistical analysis included Student t test, exact test of goodness-of-fit, Fisher's exact test, and the Cochran-Mantel-Haenszel test for repeated measures. RESULTS: Out of 232 patients, 67 (29%) belonged to the DI-SCLE group. Patients with DI-SCLE were significantly older and reported more systemic symptoms than those with I-SCLE. No statistical differences were found for presentation pattern or serology, while histopathology showed a significant association of mucin deposition (P = .000083), direct immunofluorescence positivity for granular immunoglobulin M, and C3 deposits on the basement membrane zone (P = .0041) for I-SCLE and of leukocytoclastic vasculitis (P = .0018) for DI-SCLE. LIMITATIONS: This is a retrospective study. CONCLUSION: An integrated clinical and immunopathologic evaluation is useful to differentiate I-SCLE from DI-SCLE. Older age at onset and more frequent systemic symptoms characterize DI-SCLE. Mucin deposition and immunofluorescence findings are found in I-SCLE, and leukocytoclastic vasculitis is found in DI-SCLE.

Periadnexal Nerve Hyperplasia: A Reactive Histopathological Feature and an Incidental Finding After Surgical Excision and Scar Formation.

Cutaneous nerve hyperplasia is characterized by the presence of increased and hypertrophic myelinated and unmyelinated nerve fibers in the dermis. We report a case of periadnexal nerve hyperplasia as an asymptomatic and infrequent reactive histopathological change, with no associated risk of malignancy that can be seen in scars, in patients with no syndromic stigmata.

Dermatopathology of Cutaneous Cystic Lesions: A Practical Review With Diagnostic Clues and Pitfalls.

BACKGROUND: Cystic lesions are common in the daily practice of dermatologists and dermatopathologists, and in most cases, a straightforward diagnosis can be done. Yet, some variants and situations may cause diagnostic problems or carry prognostic and/or systemic implications. OBJECTIVE: To review the histopathological features of the most frequent cystic lesions, either true cysts or pseudocysts, and provide some clues and pitfalls to bear in mind for troublesome situations such as solid-cystic tumors; uncommon variants; incidental findings; artifactual, reactive, or infectious cavities; cysts as a warning of systemic and hereditary diseases; and malignant cystic tumors, either primary or metastatic. METHODS: The histopathological diagnostic criteria of most cystic lesions and their potential caveats will be discussed, offering some diagnostic clues. RESULTS: Cystic lesions of the skin can primarily be classified into true cysts and pseudocysts. The most frequent pseudocysts are sinus pilonidalis and mucin-filled cavities. True cysts can be divided according to their epithelial origin or differentiation into epidermal/pilar cysts, cysts from glandular appendages, and from embryonic remnants. Diagnostic dilemmas and possible pitfalls in cystic lesions are reviewed, offering some keys to solve them. CONCLUSIONS: Knowledge of the histopathology of cystic lesions contributes to their correct diagnosis, improving the management of patients.

Solid carcinoma is a variant of microcystic adnexal carcinoma: A 14-case series.

BACKGROUND: Solid carcinoma is a poorly characterized malignant apocrine neoplasm as only 16 cases have been published. OBJECTIVE: To characterize its clinical, histopathological, and immunohistochemical features. METHODS: We compiled 14 cases of solid carcinoma and clinical information were updated. Hematoxylin and eosin slides were reviewed and we stained all the cases for CEA, EMA, SMA, PHLDA-1, BerP4, nestin, p53, p63, p75, CK5/6, CK7 and some with remaining material for CK14, 15, CK10, CK19, S100, CD117, and CAM5. RESULTS: All the lesions were located on the scalp. Histopathologically, all the cases were characterized by solid aggregates of neoplastic epithelial cells without nuclear atypia or mitotic figures involving all the dermis. All the cases presented perineural infiltration and most of them had cornified cystic structures. CK5/6 and p63 were positive. CEA and EMA underlined the scarce ducts. Ki67 was lower than 1%. BerEP4 and PHLDA-1 were negative. CONCLUSION: Solid carcinoma is a solid variant of MAC affecting the scalp more frequently than classic MAC, mostly in old males and showing variable-sized nests involving the entire dermis and composed by poroid, clear-cells, or a mixture of both. It is positive for p63 and CK5/6 and negative for BerEP4 and PHLDA-1. Staining features with CK19 and PHLDA1 differ from classic MAC.

Clues in Histopathological Diagnosis of Panniculitis.

BACKGROUND: Panniculitides comprise a group of heterogeneous inflammatory diseases. Nevertheless, histopathological study along with clinicopathological correlation usually led to a specific diagnosis. In most textbooks, the first step in the diagnosis is to classify them as mostly septal or lobular depending on where the inflammatory infiltrate is located. The second step is deciding if vasculitis is present or not. Finally, the third step is further characterizing the inflammatory infiltrate. However, in addition to the algorithmic approach to panniculitis diagnosis, some subtle changes may help to the diagnosis. OBJECTIVE: To review some clues in panniculitis dermatopathological diagnosis such as presence of granulation tissue, sclerotic connective tissue septa, small granulomas arranged around a central clear space, so-called ghost adipocytes, needle-shaped crystals, small lobules with a proliferation of capillaries, Splendore-Hoeppli phenomenon, refractile microspheres, neutrophilic infiltrates, granulomas and fibroplasia or presence of adipose tissue in dermis. METHODS: We have compiled 12 clues based in our personal experience in this field. LIMITATIONS: Specificity and sensibility of every clue may vary and these clues are a guide to correct diagnoses that should rely in clinicopathological correlation. CONCLUSION: Knowledge of these 12 clues will help to increase the diagnostic accuracy in panniculitis diagnosis.