Papulo-purpuric dermatitis of childhood: a distinct PLEVA-like eruption associated to SARS-CoV-2 infection. Clinical, histopathological and immunohistochemical study of 10 cases.

We observed ten children with a papular eruption with purpuric features during the SARS-CoV-2 pandemic in Northern Italy (May-December 2020). Histological examination showed signs of SARS-CoV-2-related dermatosis. Evidence of nucleocapsid viral proteins using SARS-CoV-2 (2019-nCoV) nucleocapsid antibody revealed cuticular staining of the deep portion of the eccrine glands in all cases.

Similarities in Cutaneous Histopathological Patterns between COVID-19-positive and COVID-19 High-risk Patients with Skin Dermatosis.

Only recently histopathological studies of patients with dermatosis and concomitant SARS-Cov-2 viral infection were published. Seven months into the COVID-19 pandemic, more skin biopsies of COVID-19 positive patients are taking place. We examined the histological features of 30 skin biopsies from two groups of patients: Ten specimens of patients tested positive for COVID-19 with an active systemic infection and associated dermatosis. Twenty specimens were from patients not considered COVID-positive (due to PCR swab negativity or not tested at all) with cutaneous lesions either showing viral infection symptoms (fever, cough, ageusia and severe immunocompromised condition due to HIV infection and malignancies), or presented a high risk of being infected (such as cohabitation with COVID-19 positive parents and siblings with simultaneous chilblains). This study analyses the histological and immunohistochemical (SARS-CoV-2 2019-nCoV nucleocapsid antibody) characteristics of the two groups and identifies 4 histopathological patterns. The histopathological features of the two groups present similar features that may help to identify an ongoing COVID-19 infection even in asymptomatic carriers with dermatosis.

Histopathological Study of a Broad Spectrum of Skin Dermatoses in Patients Affected or Highly Suspected of Infection by COVID-19 in the Northern Part of Italy: Analysis of the Many Faces of the Viral-Induced Skin Diseases in Previous and New Reported Cases.

Skin manifestations of COVID-19 infections are diverse and are new to the dermatology community. We had the opportunity to examine the clinical and histopathological features of several patients who were divided into 3 groups. The first group included 8 COVID-19-positive patients who were hospitalized and quarantined at home. The second group included children and young adults who presented with chilblain erythema, erythema multiforme, and urticaria-like lesions. This group of patients was negative for the COVID-19 gene sequences by polymerase chain reaction but had a high risk of COVID-19 infection. The third group included clinically heterogeneous and challenging lesions. These patients were not subject to either polymerase chain reaction tests or serological analyses because they sought dermatological attention only for a dermatosis. The histopathological analysis of these cases showed a wide spectrum of histopathological patterns. What appears to be constant in all skin biopsies was the presence of prominent dilated blood vessels with a swollen endothelial layer, vessels engulfed with red blood cells, and perivascular infiltrates, consisting mainly of cytotoxic CD8+ lymphocytes and eosinophils. In 2 cases, there was diffuse coagulopathy in the cutaneous vascular plexus. In the early phases of the disease, there were numerous collections of Langerhans cells in the epidermis after being activated by the virus. The presence of urticarial lesions, chilblains, targetoid lesions (erythema multiforme-like lesions), exanthema, maculohemorrhagic rash, or chickenpox-like lesions associated with the histopathological features mentioned previously should cause clinical dermatologists to suspect the possibility of COVID-19 infection, especially in patients with fever and cough.

Chilblain-like lesions in children following suspected COVID-19 infection.

During the COVID-19 pandemic, chilblain-like lesions have been reported in mildly symptomatic children and adolescents. We present four children investigated for suspected COVID-19 infection who presented with acral skin findings and mild systemic symptoms. Histology from one case showed signs of vasculitis with evident fibrin thrombus.

Pancreatic panniculitis: the "bright" side of the moon in solid cancer patients.

BACKGROUND: Pancreatic panniculitis is a rare complication of pancreas disorders occurring in 0.3-3% of patients, most often accompanied by the pancreatic acinar carcinoma. It presents multiple, painful, deep, ill-defined, red-brown, migratory nodules and plaques of hard elastic consistency; often ulcerated and typically located on the lower proximal and distal extremities. The pathogenesis is not fully understood, but it is thought to result from lipolysis and fat necrosis with secondary tissue inflammation induced by pancreatic enzymes. Histopathology shows subcutaneous lobular fat necrosis with anuclear adipocytes (called ghost cells) surrounded by a mixed inflammatory infiltrate. Focal calcification may also be seen. The treatment is directed to the underlying disorder, which may result in regression of skin lesions. CASE PRESENTATION: We present two cases of pancreatic panniculitis with similar clinical, laboratory, and histopathological features associated with different internal malignancy. The first case, after extensive investigations showed the presence of a pancreatic carcinoma with multiple liver metastases and a poor prognosis. The second one instead is the first case in literature where painful subcutaneous nodules of the legs were the early manifestation of a neuroendocrine carcinoma of the adrenal gland. CONCLUSIONS: Although subcutaneous fat necrosis usually occurs late in the course of a malignancy, recognition of the association with pancreatic panniculitis may prevent a long delay in the diagnosis and management of the occult neoplasm. It should be primarily considered when panniculitis is widespread and persistent, and frequent relapses or tendency to ulcerate of the nodules are regarded as red flags.

'Hints' in the horn: diagnostic clues in the stratum corneum.

The stratum corneum or horny layer is the uppermost layer of the epidermis, and is mainly responsible for the skin's barrier function. In spite of its complexity at the ultrastructural and molecular level, the features accessible to visualization on conventional histology are relatively limited. Nevertheless, knowledge of subtle clues that one may observe in the stratum corneum can prove useful in a wide range of situations in dermatopathology. We herein review a selection of common and rare entities in which the horny layer may reveal significantly important hints for the diagnosis. These clues include parakeratosis and its different patterns (focal, confluent, alternating, associated with spongiosis, epidermal hyperplasia or lichenoid changes), subcorneal acantholysis, infectious organisms in the stratum corneum (including fungal, bacterial and parasitic), thickening or thinning of the stratum corneum and the presence of different kinds of pigment. Even when normal, the horny layer may prove to be useful when seen in association with severe epidermal damage, a combination of features testifying to the acute nature of the underlying pathological process.

Clinical and dermoscopic features of atypical Spitz tumors: A multicenter, retrospective, case-control study.

BACKGROUND: Few studies have described the clinical and dermoscopic features of atypical Spitz tumors. OBJECTIVE: We sought to describe the clinical and dermoscopic features of a series of atypical Spitz tumors as compared with those of conventional Spitz nevi. METHODS: This was a multicenter, retrospective, case-control study, analyzing the clinical and dermoscopic characteristics of 55 atypical Spitz tumors and 110 Spitz nevi that were excised and diagnosed histopathologically. RESULTS: The majority of atypical Spitz tumors presented clinically as a plaque or nodule, dermoscopically typified by a multicomponent or nonspecific pattern. A proportion of lesions (16.4%) exhibited the typical nonpigmented Spitzoid pattern of dotted vessels and white lines under dermoscopy. Nodularity, ulceration, linear vessels, polymorphic vessels, white lines, and blue-white veil were associated with atypical Spitz tumors by univariate analysis, but only nodularity and white lines remained significant after multivariate analysis. In contrast, a pigmented typical Spitzoid pattern was a potent predictor of Spitz nevi, associated with 6.5-fold increased probability. LIMITATIONS: Differentiation from Spitzoid melanoma and other nonmelanocytic lesions was not investigated. CONCLUSION: Atypical Spitz tumors are polymorphic melanocytic proliferations with a nodular clinical appearance. Dermoscopically they demonstrate a multicomponent and nonspecific pattern. A typical nonpigmented Spitzoid pattern on dermoscopy (with dotted vessels and white lines) does not exclude atypical Spitz tumors.

COVID-19: The experience from Italy.

A wide range of cutaneous signs are attributed to COVID-19 infection. This retrospective study assesses the presence and impact of dermatologic manifestations related to the spread of COVID-19 in Lombardy, the geographic district with the first outbreak in Italy. A cohort of 345 patients with laboratory confirmed COVID-19 was collected from February 1, 2020 to May 31, 2020. Cutaneous signs and dermatologic diagnoses were recorded on admission, and during the course of the disease. Of the 345 patients included in the study, 52 (15%) had new-onset dermatologic conditions related to COVID-19. We observed seven major cutaneous clinical patterns, merged under 3 main groups: Exanthems, vascular lesions, and other cutaneous manifestations. Each subset was detailed with prevalence, age, duration, prognosis, and histology. Cutaneous findings can lead to suspect COVID-19 infection and identify potentially contagious cases with indolent course.

Dermoscopy and reflectance confocal microscopy of balloon cell nevi: a series of 10 cases.

BACKGROUND: Balloon cell nevus (BCN) is a rare histopathological entity. It is usually represented by an asymptomatic brown smooth or polypoid lesion, but no clinical features allow differentiation from other melanocytic nevi. Moreover, dermoscopy and reflectance confocal microscopy (RCM) aspects of BCN have been described in a few single cases. This study aims to describe a wider BCN series with dermoscopic and RCM features to assess the most frequent patterns. METHODS: Ten patients who underwent a BCN surgical excision with histological diagnosis were included in this study. Dermatoscopy and RCM were performed for each lesion, searching for the features described in literature. RESULTS: Each nevus presented as an asymptomatic, smooth brownish lesion. Regarding dermoscopy, four balloon cell nevi showed yellow globules, eight white globules, eight a light-brown network at the periphery, and eight a structureless central area; moreover, we found a hyperpigmented central blotch in four cases. RCM examination highlighted aggregates of dense nests at superficial dermis level in all BCNs, characterized by the presence of a dark nucleus surrounded by vacuolized cytoplasm. Moreover, multiple melanophages were seen at the dermal-epidermal junction in one case and superficial epidermal dendritic cells in one case. CONCLUSIONS: This series of 10 BCNs improves the dermoscopic and confocal microscopic knowledge of this rare entity. We also reported a new dermoscopic aspect represented by central hyperpigmented blotch. A correct identification of BCN with noninvasive techniques allows to avoid unnecessary surgical excision.

Immunohistochemical expression and prognostic role of CD10, CD271 and Nestin in primary and recurrent cutaneous melanoma.

BACKGROUND: CD10, CD271 and Nestin, which are proteins associated with tumor-initiating properties and/or progression potential, have not been specifically studied on malignant melanoma (MM) with cutaneous recurrences. METHODS: We evaluated the expression of CD10, CD271 and Nestin in 27 tumor samples from 16 patients. These tumor samples corresponded to 6 primary melanomas which developed 11 ITM and 10 primary melanomas without recurrences at 10-year follow-up from specimens obtained from surgical excisions of patients referred to the Unit of Dermatology, Department of Medical-Surgical and Transplant Physiopathology, University of Milan, between 2006 and 2016. RESULTS: We demonstrated a higher expression of CD271 and Nestin in primary tumors which recurred than control population, Nestin was expressed with significantly higher percentages in primary tumors than recurrences, and CD10 expression was statistically significant correlated with disease-free survival: cases with a lower score recurred lately than cases with higher scores. CONCLUSIONS: Our preliminary results suggested that CD271 and Nestin can be considered early biomarkers for the development of ITM, Nesting can be useful in differentiating primary MM from cutaneous recurrences and CD10 is associated with a rapid disease progression and may be considered a potential prognostic marker.

Cutaneous tricholemmal carcinoma: a 15-year single center experience.

BACKGROUND: Clear cell morphology has been described in several cutaneous neoplasms either as a specific feature of some entities either as a morphological variant in the spectrum, and these two entities are frequently considered together in the differential diagnosis. METHODS: We reviewed our series of cases occurred in our laboratory in order to further quantify the number of cases showing morphological features of tricholemmal differentiation and to investigate other clinical or histological difference. We retrieved 91 cases and, for each of them, all the clinical data regarding age, sex, clinical features, and clinical suspicious were collected, when available. RESULTS: The revision of the specimens concluded with a final diagnosis of tricholemmal carcinoma in 15 cases (17%), all the other cases were thus considered as squamous cell carcinoma with clear cell features. No statistically significant correlations were observed with the demografic or clinicopatholagical parameters such as age, sex or dimensions, but morphological revision highlighted a potentially greater "vertical" growth frequently not matched by a concomitant radial one in tricholemmal carcinoma than in squamous tumors. CONCLUSIONS: The debate upon the diagnostic distinction of these tumors is still ongoing with authors proposing the tricholemmal carcinoma as a variant of a squamous cell carcinoma rather than a distinct entity. Further studies are needed to confirm our data and to evaluate the reproducibility of this feature.

Skin infections by Mycobacterium chelonae following mesotherapy: A report of two cases and review of the literature.

Mesotherapy is sometimes responsible for dermal and subcutaneous infections caused by nontuberculous mycobacteria. Mycobacterium chelonae, M abscessus, and M fortuitum are usually involved. We present two cases of deep skin infections caused by M chelonae following mesotherapy. A review of the literature is included.