RESUMO
Lymphoid interstitial pneumonia (LIP) is a rare form of interstitial pulmonary disease, which has been described in association with a wide range of autoimmune disorders. Although the association of this entity with Sjogren's syndrome is well known, only a few cases are reported in relation to systemic lupus erythematosus (SLE). The aim of this paper is to review the cases reported in literature to date, as well as to describe the characteristics of these patients including the new case presented herein. We will be focusing on the case of a 36-year-old female patient diagnosed with SLE on hydroxychloroquine treatment who develops pleuritic chest pain and progressive dyspnea after 3 years of follow-up. The chest CT scan showed pleural thickening and both multiple and bilateral micronodules. A lung biopsy was also performed, revealing an infiltration of lymphocytes, plasma cells, and histiocytes in the alveolar septa suggestive of LIP. After conducting a review of the literature, we identified seven other cases describing SLE in association with LIP. The majority of them were young women, and LIP tends to appear early in the course of the disease, even as a form of initial presentation in some cases. Symptoms included cough, dyspnea, and pleuritic pain, with the exception of one case which was asymptomatic. It is noteworthy that half of the patients were positive for anti-SSA/anti-SSB autoantibodies, and some of them also met criteria for Sjogren's syndrome. Treatment with steroids and other immunosuppressive agents improved symptoms in all of them.
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Doenças Pulmonares Intersticiais , Lúpus Eritematoso Sistêmico , Pleurisia , Síndrome de Sjogren , Humanos , Feminino , Adulto , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Síndrome de Sjogren/complicações , Síndrome de Sjogren/diagnóstico , Síndrome de Sjogren/tratamento farmacológico , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/tratamento farmacológico , Doenças Pulmonares Intersticiais/etiologia , Pleurisia/complicações , Dispneia/etiologiaRESUMO
INTRODUCTION: Insulin-like growth factor-II messenger RNA-binding protein-3 (IMP3) over-expression is a predictor of tumor recurrence and metastases in some types of human melanoma. Our objective was to evaluate the immunohistochemical expression of IMP3 and other molecules related to tumor prognosis in melanoma-xeno-tumors undergoing treatment. We test the effect of radiotherapy (RT) and mesenchymal stromal cells (MSCs) treatment, analyzing the tumorigenic and metastatsizing capacity in a mice melanoma xenograft model. MATERIALS AND METHODS: We inoculated A375 and G361 human melanoma cell lines into NOD/SCID gamma mice (n = 64). We established a control group, a group treated with MSCs, a group treated with MSCs plus RT, and a group treated with RT. We assessed the immunohistochemical expression of IMP3, E-cadherin, N-cadherin, PARP1, HIF-1α, and the proliferation marker Ki-67. Additionally, we performed a retrospective study including 114 histological samples of patients diagnosed with malignant cutaneous superficial spreading melanoma (n = 104) and nodular melanoma (n = 10) with at least 5 years of follow-up. RESULTS: Most morphological and immunohistochemical features show statistically significant differences between the 2 cell lines. The A375 cell line induced the formation of metastases, while the G361 cell line provoked tumor formation but not metastases. All three treatments reduced the cell proliferation evaluated by the Ki-67 nuclear antigen (p = 0.000, one-way ANOVA test) and reduced the number of metastases (p = 0.004, one-way ANOVA test). In addition, the tumor volumes reduced in comparison with the control groups, 31.74% for RT + MSCs in the A357 tumor cell line, and 89.84% RT + MSCs in the G361 tumor cell line. We also found that IMP3 expression is associated with greater tumor aggressiveness and was significantly correlated with cell proliferation (measured by the expression of Ki-67), the number of metastases, and reduced expression of adhesion molecules. CONCLUSIONS: The combined treatment of RT and MSCs on xenografted melanomas reduces tumor size, metastases frequency, and the epithelial to mesenchymal transition/PARP1 metastatic phenotype. This treatment also reduces the expression of molecules related to cellular proliferation (Ki-67), molecules that facilitate the metastatic process (E-cadherin), and molecules related with prognosis (IMP3).
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Melanoma , Neoplasias Cutâneas , Animais , Camundongos , Humanos , Antígeno Ki-67 , Estudos Retrospectivos , Xenoenxertos , Transição Epitelial-Mesenquimal , Camundongos Endogâmicos NOD , Camundongos SCID , Linhagem Celular Tumoral , Caderinas , Biomarcadores Tumorais/metabolismoRESUMO
We test the hypothesis that PARP inhibition can decrease acute tubular necrosis (ATN) and other renal lesions related to prolonged cold ischemia/reperfusion (IR) in kidneys preserved at 4°C in University of Wisconsin (UW) solution. Material and Methods. We used 30 male Parp1(+/+) wild-type and 15 male Parp1(0/0) knockout C57BL/6 mice. Fifteen of these wild-type mice were pretreated with 3,4-dihydro-5-[4-(1-piperidinyl)butoxyl]-1(2H)-isoquinolinone (DPQ) at a concentration of 15 mg/kg body weight, used as PARP inhibitor. Subgroups of mice were established (A: IR 45 min/6 h; B: IR + 48 h in UW solution; and C: IR + 48 h in UW solution plus DPQ). We processed samples for morphological, immunohistochemical, ultrastructural, and western-blotting studies. Results. Prolonged cold ischemia time in UW solution increased PARP-1 expression and kidney injury. Preconditioning with PARP inhibitor DPQ plus DPQ supplementation in UW solution decreased PARP-1 nuclear expression in renal tubules and renal damage. Parp1(0/0) knockout mice were more resistant to IR-induced renal lesion. In conclusion, PARP inhibition attenuates ATN and other IR-related renal lesions in mouse kidneys under prolonged cold storage in UW solution. If confirmed, these data suggest that pharmacological manipulation of PARP activity may have salutary effects in cold-stored organs at transplantation.
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Isquemia/patologia , Rim/irrigação sanguínea , Inibidores de Poli(ADP-Ribose) Polimerases , Traumatismo por Reperfusão/prevenção & controle , Animais , Western Blotting , Temperatura Baixa , Isoquinolinas/farmacologia , Rim/patologia , Rim/ultraestrutura , Necrose Tubular Aguda/patologia , Necrose Tubular Aguda/prevenção & controle , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia Eletrônica , Piperidinas/farmacologia , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases/fisiologia , Traumatismo por Reperfusão/patologiaRESUMO
BACKGROUND The incidence of glomerular disease recurrence in kidney transplant patients varies according to type of glomerulopathy; therefore, it is important to know the primary chronic kidney disease etiology. C3 glomerulopathy (C3G) is characterized by deposits of C3 in immunofluorescence and its pathogeny is based on the dysregulation of the alternative complement pathway. C3G has a high recurrence rate and, given its low prevalence, only case series have been published. A higher rate of recurrence and a more aggressive course have been described in association with monoclonal gammopathy (MG). CASE REPORT We describe the case of a 78-year-old man with chronic kidney disease of unknown etiology (no significant proteinuria) and monoclonal IgGl gammopathy with low risk of progression, who received a kidney transplant, presenting accelerated deterioration of kidney function. Histopathology showed predominant C3 deposits in immunofluorescence, compatible with C3 glomerulonephritis (C3GN). He was treated with eculizumab during 4 weeks while the study was completed. The response to treatment was not favorable and the patient remained in the dialysis program. CONCLUSIONS Further studies are needed to explain the pathogenic mechanisms of complement alternative pathway dysregulation mediated by monoclonal component in patients with C3GN and MG. Patients older than 50 years who are on a waiting list for kidney transplantation should have an MG detection study. The information provided to patients with MG on a waiting list for kidney transplantation should include not only the possibility of hematologic progression but also the recurrence/de novo appearance of associated kidney pathology.
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Glomerulonefrite Membranoproliferativa , Glomerulonefrite , Gamopatia Monoclonal de Significância Indeterminada , Paraproteinemias , Insuficiência Renal Crônica , Masculino , Humanos , Idoso , Complemento C3/metabolismo , Diálise Renal , Glomerulonefrite/etiologia , Glomerulonefrite/diagnóstico , Insuficiência Renal Crônica/etiologia , Glomerulonefrite Membranoproliferativa/etiologiaRESUMO
We report an unusual case of hemangiopericytoma-like dermatofibroma in the right shoulder of an 82-year-old patient with a well-defined nodular growth located in the dermis. Microscopic study revealed a band of haphazardly arranged cells with a vascular component of gaping, simple, endothelial-lined vascular structures with intervening postcapillary venules and capillary-sized slit-like "staghorn" vascular channels filled with erythrocytes; abundant mast cells were also observed. The neoplasm cells were positive for CD68 and Factor XIIIA and negative for CD34. Few data have been published on the presence of abundant mast cells (tryptase and CD117 positive) in these neoplasm. The differential diagnosis of this entity should consider other spindle cell neoplasm, including hemangiopericytoma/solitary fibrous tumor, dermatofibrosarcoma protuberans, myopericytoma, angioleiomyoma, amelanotic melanoma, pecoma, and benign and malignant peripheral nerve tumors. We present an infrequent case of dermatofibroma with a vascular pattern resembling hemangiopericytoma and the presence of abundant mast cells, which may be responsible for this vascular component.
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Hemangiopericitoma/patologia , Histiocitoma Fibroso Benigno/patologia , Mastócitos/patologia , Neoplasias Cutâneas/patologia , Idoso de 80 Anos ou mais , Angiomioma/diagnóstico , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Biomarcadores Tumorais/metabolismo , Dermatofibrossarcoma/diagnóstico , Diagnóstico Diferencial , Fator XIIIa/metabolismo , Hemangiopericitoma/metabolismo , Hemangiopericitoma/cirurgia , Histiocitoma Fibroso Benigno/metabolismo , Histiocitoma Fibroso Benigno/cirurgia , Humanos , Masculino , Mastócitos/metabolismo , Melanoma Amelanótico/diagnóstico , Neoplasias do Sistema Nervoso Periférico/diagnóstico , Neoplasias de Células Epitelioides Perivasculares/diagnóstico , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/cirurgia , Tumores Fibrosos Solitários/diagnóstico , Resultado do TratamentoRESUMO
Background: An antibody panel is needed to definitively differentiate between adenocarcinoma (AC) and squamous cell carcinoma (SCC) in order to meet more stringent requirements for the histologic classification of lung cancers. Staining of desmosomal plaque-related proteins may be useful in the diagnosis of lung SCC.Materials and methods: We compared the usefulness of six conventional (CK5/6, p40, p63, CK7, TTF1, and Napsin A) and three novel (PKP1, KRT15, and DSG3) markers to distinguish between lung SCC and AC in 85 small biopsy specimens (41 ACs and 44 SCCs). Correlations were examined between expression of the markers and patients' histologic and clinical data.Results: The specificity for SCC of membrane staining for PKP1, KRT15, and DSG3 was 97.4%, 94.6%, and 100%, respectively, and it was 100% when the markers were used together and in combination with the conventional markers (AUCs of 0.7619 for Panel 1 SCC, 0.7375 for Panel 2 SCC, 0.8552 for Panel 1 AC, and 0.8088 for Panel 2 AC). In a stepwise multivariate logistic regression model, the combination of CK5/6, p63, and PKP1 in membrane was the optimal panel to differentiate between SCC and AC, with a percentage correct classification of 96.2% overall (94.6% of ACs and 97.6% of SCCs). PKP1 and DSG3 are related to the prognosis.Conclusions: PKP1, KRT15, and DSG3 are highly specific for SCC, but they were more useful to differentiate between SCC and AC when used together and in combination with conventional markers. PKP1 and DSG3 expressions may have prognostic value.
Assuntos
Adenocarcinoma/diagnóstico , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/diagnóstico , Desmossomos/metabolismo , Neoplasias Pulmonares/diagnóstico , Adenocarcinoma/metabolismo , Carcinoma de Células Escamosas/metabolismo , Desmogleína 3/metabolismo , Diagnóstico Diferencial , Feminino , Humanos , Imuno-Histoquímica , Queratina-15/metabolismo , Neoplasias Pulmonares/metabolismo , Masculino , Pessoa de Meia-Idade , Placofilinas/metabolismo , Prognóstico , Sensibilidade e EspecificidadeRESUMO
Plasma cell-rich acute rejection (PCAR) is a rare type of allograft rejection in renal transplantation. It is characterized by the presence of mature plasma cells that compromise more than 10% of inflammatory cells infiltrating the renal graft. The pathogenesis of PCAR is unknown, appears late, and has been related mainly to insufficient immunosuppression or infections. The treatment is not clearly defined, and the graft survival is poor. Here, we report a case series of 3 Spanish patients diagnosed with PCAR accompanied by donor-specific antibodies (DSA) after kidney transplantation. Mean to diagnosis was 2-12 years post-transplantation, and they began with abrupt deterioration of renal function. All patients were women and had preceding viral infection. In addition, two of the three patients recognize a doubtful adherence to immunosuppression. About treatment, 2 of the 3 patients, because the biopsy of the renal graft showed signs suggestive of incipient antibody-mediated rejection (ABMR) (glomerulitis, capilaritis, transplant glomerulopathy), were started with corticosteroids, anti-thymoglobulin, plasmapheresis, and intravenous immunoglobulins. The last patient, who only showed PCAR at biopsy, was treated with corticosteroids and anti-thymoglobulin. After treatment, graft function improved in all of them, but one patient developed an ABMR and another required a dialysis program, all of which indicates the difficulty in management and treatment of PCAR.
Assuntos
Rejeição de Enxerto/imunologia , Transplante de Rim/efeitos adversos , Plasmócitos/imunologia , Complicações Pós-Operatórias/imunologia , Adulto , Anticorpos/sangue , Anticorpos/imunologia , Biópsia , Feminino , Rejeição de Enxerto/sangue , Humanos , Rim/imunologia , Rim/patologia , Complicações Pós-Operatórias/sangue , Doadores de Tecidos , Transplantes/imunologia , Transplantes/patologiaAssuntos
Adenoma de Glândula Sudorípara/patologia , Glândulas Écrinas/patologia , Doenças do Pé/patologia , Doenças do Pé/cirurgia , Neoplasias das Glândulas Sudoríparas/patologia , Neoplasias das Glândulas Sudoríparas/cirurgia , Adenoma de Glândula Sudorípara/classificação , Adenoma de Glândula Sudorípara/cirurgia , Idoso , Diagnóstico Diferencial , Glândulas Écrinas/cirurgia , Humanos , Masculino , Dedos do Pé/patologia , Dedos do Pé/cirurgia , Resultado do TratamentoAssuntos
Glomerulonefrite Membranoproliferativa , Parvovirus B19 Humano , Humanos , Parvovirus B19 Humano/isolamento & purificação , Glomerulonefrite Membranoproliferativa/virologia , Glomerulonefrite Membranoproliferativa/etiologia , Glomerulonefrite Membranoproliferativa/patologia , Infecções por Parvoviridae/complicações , Infecções por Parvoviridae/diagnóstico , Feminino , MasculinoRESUMO
Obesity-related comorbidities are, in large part, originated from the dysfunction of adipose tissue. Most of them revert after the normalization of body mass. Adipose tissue is essentially occupied by adipocytes. However, different populations of immunological cells and adipocyte precursor cells (AdPCs) are the main cellular components of tissue. During obesity, body fat depots acquire a low-level chronic inflammation and adipocytes increase in number and volume. Conversely, weight loss improves the inflammatory phenotype of adipose tissue immune cells and reduces the volume of adipocytes. Nevertheless, very little is known about the evolution of the human AdPCs reservoir. We have developed a flow cytometry-based methodology to simultaneously quantify the main cell populations of adipose tissue. Starting from this technical approach, we have studied human adipose tissue samples (visceral and subcutaneous) obtained at two different physiological situations: at morbid obesity and after bariatric surgery-induced weight loss. We report a considerable increase of the AdPCs reservoir after losing weight and several changes in the immune cells populations of adipose tissue (mast cells increase, neutrophils decrease and macrophages switch phenotype). No changes were observed for T-lymphocytes, which are discussed in the context of recent findings.
Assuntos
Adipócitos/citologia , Tecido Adiposo/citologia , Cirurgia Bariátrica , Citometria de Fluxo/métodos , Células-Tronco/citologia , Redução de Peso/fisiologia , Adulto , Contagem de Células , Tamanho Celular , Estudos de Coortes , Células Endoteliais/metabolismo , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Células Estromais/citologiaRESUMO
The hemophagocytic syndrome is a serious clinical-histological entity secondary to different diseases. Collapsing glomerulonephritis is a proliferative podocytopathy that usually has an unfavorable renal prognosis. We present a case in which both entities were associated, which is an infrequent form of hepatosplenic T-cell lymphoma. In addition, we review the role of the markers of podocyte dedifferentiation in this glomerulopathy and its pathophysiology and treatment.
El síndrome hemofagocítico es una condición clínica e histológica grave, secundaria a diferentes procesos. La glomerulonefritis colapsante es una podocitopatía proliferativa, generalmente de pronóstico desfavorable para la función renal. Se presenta un caso en el que las dos condiciones aparecieron asociadas, lo cual es una forma infrecuente de presentación del linfoma hepatoesplénico de células T. Se discute, asimismo, el papel de los marcadores de desdiferenciación podocitaria en esta glomerulopatía, y se revisan la fisiopatología y el tratamiento.
Assuntos
Desdiferenciação Celular , Glomerulonefrite/patologia , Podócitos/patologia , Glomerulonefrite/complicações , Humanos , Neoplasias Hepáticas/complicações , Linfo-Histiocitose Hemofagocítica/etiologia , Linfoma de Células T/complicações , Masculino , Pessoa de Meia-Idade , Neoplasias Primárias Múltiplas/complicações , Neoplasias Esplênicas/complicaçõesRESUMO
The aim of the present study is to analyze the effects of 5-aminoisoquinoline (5-AIQ), a poly(ADP-ribose) polymerase-1 (PARP1) inhibitor, over renal dysfunction and fibrosis during recovery phase of cisplatin (CisPt)-induced acute kidney injury (AKI) in rats. Male Wistar rats were distributed in three groups (n=8 each group): control, CisPt, and CisPt + 5-AIQ. Control and CisPt groups received a subcutaneous injection of either saline or 7 mg/kg CisPt, respectively. CisPt + 5-AIQ group received two intraperitoneal injections of 10 mg/kg 5-AIQ 2 h before and 24 h after CisPt treatment. Thirteen days after the treatment, rats were housed in metabolic cages and 24-h urine collection was made. At day 14, CisPt-treated rats showed increased diuresis, N-acetyl-ß-d-glucosaminidase (NAG) excretion, glucosuria and sodium fractional excretion (NaFE), and decreased creatinine clearance (CrCl). 5-AIQ significantly increased CrCl and decreased NAG excretion, glucosuria, and NaFE. In plasma, CisPt increased sodium, urea, and creatinine concentrations, while 5-AIQ treatment decreased these variables to the levels of control group. 5-AIQ completely prevented the body weight loss evoked by CisPt treatment. CisPt also induced an increased renal expression of PAR polymer, α-smooth muscle actin (α-SMA), transforming growth factor-ß1 (TGF-ß1), and collagen-IV. These variables were decreased in CisPt + 5-AIQ group. Tubular lesions and renal fibrosis were also decreased by 5-AIQ treatment. We conclude that inhibition of PARP1 with 5-AIQ can attenuate long-term nephrotoxic effects associated with the CisPt treatment, preventing renal dysfunction and body weight decrease and ameliorating tubular lesions and collagen deposition.
Assuntos
Injúria Renal Aguda , Cisplatino/efeitos adversos , Isoquinolinas/farmacologia , Rim , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/metabolismo , Animais , Cisplatino/farmacologia , Fibrose , Rim/metabolismo , Rim/patologia , Testes de Função Renal , Masculino , Ratos , Ratos WistarRESUMO
PURPOSE: To examine differences in morphology and in immunophenotype subsets between chronic periodontitis (CP) and peri-implantitis (P-I) lesions and to test the diagnostic agreement (CP vs P-I) among three independent observers, based on histopathological features. MATERIALS AND METHODS: This observational cross-sectional study included 15 gingival biopsies of CP lesions and 15 biopsies of P-I lesions for double-blinded examination by three independent pathologists. Inflammatory infiltrate intensity was assessed semiquantitatively on a 4-point scale, determining the percentage of lymphocytes, plasma cells, monocytes/macrophages, and granulocytes and the presence/absence of bacterial colonies. Immunohistochemical analyses were performed to verify the inflammatory infiltrate subset data (CD45, CD38, CD68 and myeloperoxidase [MPO]-positive), and number of vessels. Kappa statistic was used to evaluate the degree of diagnostic concordance among examiners. RESULTS: Inflammatory infiltrate was significantly more severe in P-I cases (P = 0.01), which showed a significantly higher percentage of plasma cells (P = 0.004) than in CP cases. Immunohistochemically, the percentage of leukocyte subsets was generally lower in CP (CD38: 32.05%; CD68: 6.45% and MPO: 8.62%) than in P-I (CD38: 61.13%; CD68: 9.09% and MPO: 7.47%) (CD38 P = 0.001, P = 0.955 and P = 0.463, for remaining subsets, respectively; Mann-Whitney U-test). The inter-observer diagnostic agreement was poor or slight (kappa = -0.18 to 0.13). CONCLUSIONS: Despite the significantly more severe general inflammatory infiltrate and plasma cells in P-I cases, it proved difficult to detect reliable differential morphological features based on histopathological images of these CP and P-I soft-tissue samples, obtaining low inter-observer and intra-observer diagnostic agreement. Conflict of interest statement: This investigation was partially supported by Research Groups #CTS-138 and #CTS-583 (Junta de Andalucía, Spain). No conflict of interest.
Assuntos
Periodontite Crônica/imunologia , Periodontite Crônica/patologia , Peri-Implantite/imunologia , Peri-Implantite/patologia , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Imuno-Histoquímica , Imunofenotipagem , Masculino , Pessoa de Meia-IdadeRESUMO
Ataxia-telangiectasia (A-T) is a rare disease characterized by neurodegenerative alterations, telangiectasia, primary immunodeficiency, extreme sensitivity to radiation, and susceptibility to neoplasms. A-T patients have inactivation of ataxia-telangiectasia-mutated (ATM) protein, which controls DNA double-strand break repair and is involved in oxidative stress response, among other functions; dysfunctional control of reactive oxygen species may be responsible for many of the clinical manifestations of this disease. To the best of our knowledge, hepatic lesions of steatohepatitis have not previously been reported in A-T patients. The present study reports the case of a 22-year-old man diagnosed with A-T at the age of 6 years who was referred to our Digestive Disease Unit with a three-year history of hyperlipidemia and liver test alterations. Core liver biopsy showed similar lesions to those observed in nonalcoholic steatohepatitis. Immunohistochemical staining disclosed the absence of ATM protein in hepatocyte nuclei. We suggest that the liver injury may be mainly attributable to the oxidative stress associated with ATM protein deficiency, although other factors may have made a contribution. We propose the inclusion of A-T among the causes of nonalcoholic steatohepatitis, which may respond to antioxidant therapy.
RESUMO
Mesenteric inflammatory venoocclusive disease is an uncommon cause of intestinal ischemia. Certain diseases, such as hypercoagulation disorders, autoimmune diseases, or drugs have been associated with the pathogenesis of mesenteric inflammatory venoocclusive disease. Here, we report a patient with Sjögren's syndrome who underwent surgery for suspected acute appendicitis with a subsequent pathological diagnosis of mesenteric inflammatory venoocclusive disease.
RESUMO
UNLABELLED: The aim of this study was to characterize the morphology and immunophenotype of ganglion cysts (GCs) and explore their histogenetic origin. MATERIAL AND METHODS: A cross-sectional morphological and immunohistochemical study of 354 GCs used the following antibody panel: vimentin, specific actin, ß-actin, smooth-muscle actin, smoothelin, h-caldesmon, ß-catenin, desmin, calponin, podoplanin, keratins 5/6, E-cadherin, cyclooxygenase 2 (COX-2), lysozyme, CD10, CD31, CD33, CD34, CD68, Ki-67, and PCNA. Double-blind semi-quantitative analyses were conducted to evaluate the immunopositivity on a 4-point scale. Samples from 10 synovial membranes and 10 scapholunate ligaments were compared. GCs showed a hyalinized wall with mesenchymal spindle cells and were intensely positive for vimentin, actins, h-caldesmon, calponin in all cases and for podoplanin in 53% of cases, suggesting features of early muscle differentiation, without ruling out a myofibroblastic origin. Focal cavity lining of non-synovial flat or raised cells (CD34/CD31/CD10/E-cadherin-negative and podoplanin-positive in 34% of cases) was detected in 93% of cases, showing differential expression with synovial membrane and scapholunate ligament cells. Nuclear positivity for proliferative markers was observed in GC wall cells (258.1±255; 1019.3±316 positive cells/mm², Ki-67 and PCNA, respectively) but positivity for these markers was significantly lower (p⟨0.001 Mann Whitney U-test) in scapholunate ligament samples. CONCLUSION: In this first immunohistochemical study of GCs, focal cellular lining of the cavity was observed in almost all cases, and the immunophenotype was identical to that of GC wall cells. These cells are immunohistochemically different from synoviocytes and scapholunate ligament cells and show characteristics of myofibroblasts or mesenchymal cells undergoing early muscle differentiation.