Congenital Unilesional Cutaneous Langerhans Cell Histiocytosis: A Case Report.

ABSTRACT: Langerhans cell histiocytosis (LCH) is a clonal proliferation of bone-marrow-derived cells, which normally reside as epidermal and mucosal dendritic cells involved in antigen presentation. It is a rare disease more common in children than adults, that is believed to be neoplastic in most cases. The diagnosis is based on clinical and radiological findings in combination with histopathologic, immunophenotypic, or ultrastructural analyses. LCH have a broad spectrum of clinical manifestations, ranging from benign cutaneous lesions to malignant multisystem disease. Based on the extent of involvement at diagnosis, LCH can be divided in single-system LCH when only one organ or system is involved, usually with multiple lesions, and multisystem LCH, when 2 or more organs or systems are involved at diagnosis. One variant of LCH is characterized by congenital isolated cutaneous involvement. It typically manifests at birth or in the postnatal period with a widespread eruption of red-to-brown papulo-nodules or, more uncommonly, a solitary lesion. The overall prognosis for single lesion skin limited LCH is excellent and most lesions spontaneously resolve within 4-18 weeks. Systemic involvement is rare. Skin findings cannot predict systemic disease and obtaining an oncology consultation is recommended for further evaluation. Herein, we present an additional case in a full-term, well-appearing, female infant with an isolated, asymptomatic, ulcerated, papule of the left arm, that was noted at birth.

Acute Generalized Exanthematous Pustulosis (AGEP) in 12 Patients Treated for SARS-CoV-2 Positive Pneumonia.

ABSTRACT: The novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is rapidly spreading throughout the world. The study describes 12 patients with SARS-CoV-2 pneumonia, who developed an acute erythematous rash with nonfollicular pinhead-sized pustules, without mucosal involvement. The clinical differential diagnosis was viral rash, acute generalized exanthematous pustulosis (AGEP), or multiform erythema. computed tomography with a diagnosis of interstitial pneumonia and a respiratory tract sample positive for SARS-CoV-2 in a reverse transcriptase polymerase chain reaction assay. Patients had signs of respiratory distress and were treated with hydroxychloroquine, darunavir, ritonavir, heparin, ceftriaxone, and azithromycin. Punch biopsies showed subcorneal pustules typical of AGEP. Dermal microvascular injury and thrombosis as described in skin damage by SARS-CoV-2 infection was not observed. The direct immunofluorescence for IgG, IgA, IgM, and C3 was negative in 8 patients investigated. A polymerase chain reaction for RNA SARS-CoV-2 performed on frozen skin was negative in 5 of 6 patients. Most of our patients were treated with systemic corticosteroids. After some days (4-10), the diffuse erythema and pustules had improved. AGEP is classified as a severe cutaneous adverse reaction, provoked by drugs and acute infections. Characteristically, removal of the offending agent leads to spontaneous resolution typically in less than 15 days. The recognition of AGEP is important, in order to avoid confusion with a systemic infection and consequently to avoid incorrect treatment. Cutaneous adverse reactions to drugs are common and are major health problems worldwide causing considerable costs for health care systems. We suggest that in the patients with AGEP during SARS-CoV-2 pneumonia, viral infection is a risk factor for developing drug reaction.

A case of trichogerminoma: a rare cutaneous follicular neoplasm.

Trichogerminoma, first described by Sau et al. in 1992, is a rare cutaneous adnexal neoplasm of the hair germ cell and usually associated with benign clinical course and favorable outcome. About 30 cases have been reported, all with similar histological features. However, due to a small but potential risk of malignancy, complete excision of the tumor is the treatment of choice. There is still controversy over its inclusion into the spectrum of trichoblastoma.Herein, we report an additional case occurring in the left buttock of a 47-year-old female, presenting with a subcutaneous solitary nodule composed of lobules of basaloid cells, with peripheral palisading and round cell nests or "cell balls" arranged in the central part. The lobules are separated by a fibrous or myxoid stroma. There are no clefts separating the tumor cells and surrounding stroma, but clefts separating stroma by the surrounding adipose tissue can be seen. Typical mitotic figures are frequently present (4-5 per 10 high-power fields). Immunohistochemistry shows the tumor cells are positive for pan-CK (AE1/AE3), CK5/6, p40, GATA 3, whereas they are negative for CK7, CK20, chromogranin A, synaptofisin, androgen receptor, estrogen receptor, and calretinin. Staining for CK20, synaptofisin, and chromogranin A detect Merkel cells scattered within the lobules. Ki67 highlights a nuclear proliferative rate of about 20%.Trichogerminoma should be distinguished from other trichogenic tumors made up of basoloid cells or hair follicular differentiation. The mainly differential diagnosis includes trichoblastoma, trichoepitelioma, tricholemmoma, and basal cell carcinoma.Herein, we report a case of trichogerminoma which, unlike the cases previously reported, showed numerous mitotic figures and a higher Ki67 nuclear proliferative rate.

NeuN, a DNA-binding neuron-specific protein expressed by Merkel cell carcinoma: analysis of 15 cases.

AIM: Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma, with an increasing worldwide incidence. It presents as a painless red to purple nodule on sun-exposed skin. MCC is presumed to arise from resident cutaneous Merkel cells. The pathogenesis of MCC is likely multifactorial with immunosuppression, UV-induced skin damage, and Merkel cell polyomavirus contributing to the development. The diagnosis of MCC relies upon characteristic morphologic features and use of immunohistochemical stains. Histologically, the differential diagnosis of Merkel cell carcinoma includes the 'small round cell' tumor group, particularly metastatic small cell carcinoma and hematological malignancies. This study investigates the expression of NeuN antibody, which recognizes the protein NeuN, normally present in most neuronal cell types and neuronal tumors, in Merkel cell carcinomas. METHODS AND RESULTS: Fifteen cases of Merkel cell carcinoma (7 men and 7 women; mean age 74 years) were retrieved from the institute database between the years 2011-2020. The immunohistochemical profile was investigated: CK20 (14/14), Neurofilament, (12/12), Synaptophysin (14/14); Chromogranin A (11/13), PAX5 (10/12), TDT (5/12), CK7 (1/14), TTF1 (0/14). Infection by Polyoma virus was detected in 11 of 14 patients. Most tumors showed middle/strong expression of NeuN. No cutaneous structures, or epidermal Merkel cells, showed expression of NeuN. The expression of NeuN was investigated in 17 primary small cell lung carcinomas: 2 cases were positive for Neu-N. CONCLUSIONS: Awareness of the staining pattern of Neu-N could aid in diagnosis of Merkel cell carcinoma, avoiding misinterpretation and erroneous diagnosis with other tumors.

Combined renal proximal tubulopathy and crystal storing histiocytosis in a patient with κ light chain multiple myeloma.

Multiple myeloma accounts for 10-15% of all hematologic malignancies, and 20% of deaths related to cancers of the blood and bone marrow. Diagnosis is defined by the presence of a serum monoclonal spike (M-spike) of more than 3 g/dL or more than 10% clonal plasma cells in the bone marrow and at least one myeloma-defining event, such as hypercalcemia, anemia, bone lesions, or renal impairment. The kidney is a major target organ, and renal impairment is frequently the first manifestation of the disease. Renal damage occurs in up to 40% of patients and 10-20% will require dialysis. Monoclonal immunoglobulin light chains are the major causes of renal complications in multiple myeloma. Glomerular disease, with the deposition of monoclonal immunoglobulins or their components, includes monoclonal immunoglobulin deposition disease, AL or AH amyloidosis, type I cryoglobulinemia, proliferative glomerulonephritis with monoclonal IgG deposits, immunotactoid glomerulopathy, and fibrillary glomerulonephritis. In addition, tubulointerstitial diseases with the deposition of monoclonal immunoglobulins or their components, are constituted by light chain cast nephropathy, light chain proximal tubulopathy, and crystal-storing histiocytosis.We report the case of a 66-year-old woman who presented with albumin-predominant moderate proteinuria and renal failure. Serum and urine immunofixation electrophoresis showed monoclonal κ light chain in both. Renal biopsy confirmed κ-restricted crystal-storing renal disease involving proximal tubular epithelial cells and crystal storing histiocytosis. Multiple myeloma with crystal storing histiocytosis was discovered in bone marrow biopsy. Thus, we present an unusual case of a myeloma patient presenting light chain proximal tubulopathy and crystal-storing histiocytosis both in the kidney and in the bone marrow.

Langerhans cell histiocytosis of an intra-mammary lymph node in an 18-year-old woman.

We describe an 18-year-old woman with several month's history of a 12 x 7 mm palpable mammary nodule, that was hypoechoic, with regular margins and vascularization areas by ultrasound. A fibroadenoma was hypothesized (American College of Radiology BI-RADS 3). A 14 G needle biopsy was performed, showing a LC proliferation suspected for LCH of a lymph node, with florid dermatopathic lymphadenopathy in differential diagnosis. The multidisciplinary team of the breast clinic decided to perform a lumpectomy and a diagnosis of LCH involving an intra-mammary lymph node was made. Langerhans cells (LC) are dendritic cells characterized by grooved nuclei, irregular nuclear contours, and abundant cytoplasm, that normally reside in the skin and mucosal surfaces. They were positive for CD1a, langerin/CD207, and S100 by immunohistochemistry. Langerhans cell histiocytosis (LCH) is a clonal proliferation of histiocytes that is thought to be neoplastic in most cases. Reactive LC can be distinguished from LCH by cyclin D1 immunostaining, which is positive only in LCH. About 50% of cases have BRAF V600E mutations. The revised classification of histiocytes divides LCH in subtypes: LCH SS (single system), LCH lung positive, LCH Multiple System/Risk Organ negative and LCH Multiple System/Risk Organ positive. Localized disease can progress to multisystem involvement. The diagnosis of LCH is based on clinical and radiological findings in combination with histopathological, immunophenotypic or ultrastructural analyses identifying tissue infiltration by LC. It is recommended that biopsy confirmation of suspected LCH be performed in all cases. Lymph nodes may be the only site of disease or a part of multisystem involvement by LCH. The histologic differential diagnosis is discussed.

Molecular profiling of advanced non-small cell lung cancer in the era of immunotherapy approach: a multicenter Italian observational prospective study of biomarker screening in daily clinical practice.

AIMS: Heterogeneous implementation of molecular tests in current diagnostic algorithm at a European and international level is emerging as a major issue for efficient lung cancer molecular profiling. METHODS: From May 2017 until October 2017, N=1612 patients referring to 13 Italian institutions were selected, at advanced stage non-small cell lung cancer (NSCLC), and prospectively evaluated. Principal endpoints were: the percentage of diagnoses performed on cytological and histological material, the proportion of requests for epidermal growth factor receptor (EGFR) mutational status, and resistance mutations detected on tissue and/or liquid biopsy samples after first-generation or second-generation tyrosine kinase inhibitors, the proportion of requests for anaplastic lymphoma kinase (ALK) gene rearrangements, ROS proto-oncogene 1 (ROS1) and Kirsten Rat Sarcoma (KRAS) determinations, the proportion of requests for programmed death-ligand1 (PD-L1) evaluation and, finally, the different assays used for the detection of EGFR mutations, ALK and ROS1 gene rearrangements and PD-L1 expression. RESULTS: Of 1325 patients finally included, only 50.8% requests were related to driver mutations with target agents already available in first-line at that preplanned time, while 49.2% were associated with PD-L1, ROS1, KRAS and others. Multiplex genomic assays (such as next-generation sequencing) were considered by all participating centres. CONCLUSIONS: To the best of our knowledge, this is the first study in a 'real-life daily practice' involving both pathologists and oncologists evaluating routinely workflow and trends towards improvements in molecular requests. Collected data aim to describe the applied algorithms and evolution of molecular screening for stage IV NSCLC in clinical practice.

Impact of laterality and mucinous histology on relapse-free and overall survival in a registry-based colon cancer series.

Recent data suggest that tumor laterality and mucinous histology may be clinically relevant. We investigated how both variables impact on the prognosis and the response to therapies in a large population-based cohort of cancer patients. Incidence data, clinical and pathological features, and outcome were systematically collected from the Tumor Registry of Parma over the years 2004-2009. Survival data were modeled by multivariable analysis. 1358 patients affected by stage I-IV colon cancer were considered; 661 (49%) had right-sided and 697 (51%) left-sided tumors. 144 (11%) had mucinous (MAC) and 1214 (89%) non-mucinous (NMAC) histology. MACs and NMACs of the right colon showed no difference in stage distribution, whereas left colon MACs were more frequently in an advanced stage (stage IV) (p = 0.008). Stage IV right colon tumors had a poorer overall survival than stage IV left-sided colon cancers (75th percentile 20 vs 34 months, p < 0.001). At relapse, MACs were less responsive to systemic therapy and had worse survival compared with NMACs regardless of tumor side (7.1 vs 13.1 months, p = 0.018). Right-sided colon cancers had poorer survival compared to left-sided tumors; the effect was mainly attributable to NMACs. At relapse, MACs had unfavorable prognosis regardless of the primary tumor-side.

Understanding the structural features of symptomatic calcific aortic valve stenosis: A broad-spectrum clinico-pathologic study in 236 consecutive surgical cases.

BACKGROUND: With age, aortic valve cusps undergo varying degrees of sclerosis which, sometimes, can progress to calcific aortic valve stenosis (AVS). To perform a retrospective clinico-pathologic investigation in patients with calcific AVS. METHODS: We characterized and graded the structural remodeling in 236 aortic valves (200 tricuspid and 36 bicuspid) from patients with calcific AVS (148 males; average 72years); possible relationships between general/clinical/echocardiographic characteristics and the histopathologic changes were explored. Twenty autopsy aortic valves served as controls. In 40 cases, we also tested the immunohistochemical expression of metalloproteinases and cytokines, and characterized the inflammatory infiltrate. In 5 cases, we cultured cusp stem cells and explored their potential to differentiate into osteoblasts/adipocytes. RESULTS: AVS cusps showed structural remodeling as severe fibrosis (100%), calcific nodules (100%), neoangiogenesis (81%), inflammation (71%), bone metaplasia with or without hematopoiesis (6% and 53%, respectively), adipose metaplasia (16%), and cartilaginous metaplasia (7%). At multivariate analysis, AVS degree and interventricular septum thickness were the only predictors of remodeling (barring inflammation). All the tested metalloproteinases (except MMP-13) and cytokines were expressed in AVS cusps. Inflammation mainly consisted of B and T lymphocytes (CD4+/CD8+ cell ratio 3:1) and plasma cells. AVS changes were mostly different from typical atherosclerosis. Cultured mesenchymal cusp stem cells could differentiate into osteoblasts/adipocytes. CONCLUSIONS: Structural remodeling in AVS is peculiar and considerable, and is related to the severity of the disease. However, the different newly formed tissues-where "valvular interstitial cells" play a key role-and their well-known slow turnover suggest a reverse structural remodeling improbable.

Persistent lone atrial fibrillation: clinicopathologic study of 19 cases.

BACKGROUND: The extent to which atrial myocardium is remodeled in patients with persistent lone atrial fibrillation (LAF) is largely unknown. OBJECTIVE: The purpose of this study was to perform a clinicopathologic investigation in patients with persistent LAF. METHODS: We characterized structural and molecular remodeling in atrial biopsies from 19 patients (17 males, mean age 49 years) with persistent (>7 days; n = 8) or long-lasting persistent (>1 year; n = 11) LAF who underwent surgical ablation. Atrial tissue from 15 autopsy samples without clinicopathologic evidence of heart disease served as controls. RESULTS: Morphometric analysis showed cardiomyocyte hypertrophy and greater amounts of myolytic damage and interstitial fibrosis in persistent LAF patients compared to controls (P <.0001). Atrial tissue levels of heme oxygenase-1 and 3-nitrotyrosine were increased in persistent LAF patients (P <.001), consistent with oxidative stress. Levels of superoxide dismutase-2, interleukin-8, interleukin-10, tumor necrosis factor-α, and thiobarbituric acid reactive substance were greater in controls than in persistent LAF patients. Immunoreactive signal for connexin43 was reduced more frequently in persistent LAF patients than controls. There was no correlation between features of structural or molecular remodeling and clinical parameters, including persistent LAF duration. CONCLUSION: In persistent LAF patients, the atria are modified by structural remodeling and molecular changes of oxidative stress. Tissue changes in persistent LAF appear to occur early after its onset and are qualitatively no different than those observed in patients with atrial fibrillation related to conventional risk factors. These findings suggest that different types of atrial fibrillation are associated with the same spectrum of tissue lesions. Early intervention to restore sinus rhythm in persistent LAF patients may prevent irreversible tissue change, especially interstitial fibrosis.

Heme oxygenase-1 expression in the left atrial myocardium of patients with chronic atrial fibrillation related to mitral valve disease: its regional relationship with structural remodeling.

Atrial fibrillation becomes a self-perpetuating arrhythmia as a consequence of electrophysiologic and structural remodeling involving the atrium. Oxidative stress may be a link between this rhythm disturbance and electrophysiologic remodeling. The aim of this study was to evaluate whether the heme oxygenase-1 (HO-1) marker of oxidative stress was more expressed in left atrial sites with stronger structural remodeling in patients affected by chronic atrial fibrillation (CAF) and mitral valve disease (MD). Myocardial samples were taken from the left atrial posterior wall (LAPW) and left atrial appendage (LAA) of 24 patients with CAF-MD in addition to 10 autopsy controls. The levels of HO-1 messenger RNA (mRNA) and HO-1 protein in each pathologic LAPW and LAA were quantified using reverse transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. Furthermore, light microscopy was used to morphometrically evaluate the differential myocyte and interstitial changes in the same CAF-MD LAPW and LAA samples. In controls, HO-1 protein was quantified using enzyme-linked immunosorbent assay. Unlike controls, patients with CAF-MD had higher levels of HO-1 mRNA and its protein product, expressed as LAPW/LAA ratios, in the LAPW (2.18 +/- 1.18, P < .0001, and 1.55 +/- 0.67, P < .005), and their LAPW also showed greater histologic changes in myocytolytic myocytes (15.1% +/- 3.1% versus 6.9% +/- 3.3%, P < .0001), interstitial fibrosis (8.2% +/- 2.2% versus 2.8% +/- 1.2%, P < .0001), and capillary density (816 +/- 120 number/mm(2) versus 1114 +/- 188 number/mm(2); P < .05). In addition, markers of oxidative stress were immunohistochemically studied with antinitrotyrosine and anti-iNOS antibodies. In patients with CAF-MD, the inducible enzyme HO-1 is more expressed in the left atrial areas that show greater structural remodeling. This finding strongly suggests a pathogenetic relationship between oxidative stress and the degree of histologic change.