Spinal intradural endodermal cyst

Purpose: Epithelial cysts of the central nervous system, according to the type of cell origin; neuroepithelial or endodermal type. Endodermal cysts are rare forms of benign tumors. In this presentation, we present a 35-year-old male patient with typical histopathologic features and due to the presence of this rare lesion. We aimed to present this rare case and emphasize the importance of cystic epithelial cell differences. Methods: Neurenteric cysts, cyst lining epithelium of cell types were analyzed using immunohistochemical diagnostic methods. Results: The importance of the cell type in the endodermal cyst is also emphasized and the frequency of recurrence in cysts that have goblet-columnar epithelial component. This epithelium is increasing the risk of recurrences. However, the other cause of recurrence is also incomplete excision. Therefore, the complete excision of ECs is important, not only for avoiding recurrence but also for differentiating cell types for ECs and predicting recurrence risk. Conclusions: The precise pathologic diagnosis of cell type determines the risk of recurrence. Neurosurgeons should exert their best efforts to achieve complete excision of the cysts.

Utilization of cell proliferation markers to diagnose cystic jaw pathologies

Markers of cell proliferation are widely used as diagnostic and prognostic tools. Coincident estimation of these markers increases the precise evaluation of the proliferative status of different tissues and can also be helpful in determining progression, aggressiveness and prognosis of the lesions. The current study investigated the expression of PCNA and MCM3 cell proliferation markers in 40 formalin fixed paraffin embedded tissue blocks of odontogenic keratocyst (OKC) and unicystic ameloblastoma (UA) cases using immunohistochemistry method. Markers` expression based on the intensity, percentage of positively stained cells and localization of reaction through the cyst lining epithelium was separately analyzed for each marker using Chi square test, the results of which were significant for the two markers (P < 0.05). Both markers revealed statistically significant differences between OKC and UA cases regarding markers expression intensity, positivity score and localization of reaction through the epithelium. Mural UA histologic variant was significantly different than luminal and intraluminal variants. The correlation coefficient between the two markers was found to be 0.86.

Interpretive Errors in Fine-Needle Aspiration of Thyroid: A 13-Year Institutional Experience in Lebanon

<b><i>Introduction:</i></b> Fine-needle aspiration (FNA) is a worldwide established diagnostic tool for the assessment of patients with thyroid nodules. All thyroid FNA interpretive errors (IEs) were reviewed at the American University of Beirut Medical Center over a 13-year period, in order to identify and analyze them. <b><i>Materials and Methods:</i></b> All FNAs and their corresponding pathology results are correlated yearly for quality assurance. Discrepant cases are segregated into sampling errors and IEs. All thyroid FNAs with IEs were collected from 2005 to 2017. FNA and pathology slides were reviewed by trained, board-certified cytopathologists, adhering to the latest Bethesda criteria. Reasons for erroneous diagnoses were studied. <b><i>Results:</i></b> There was a total of 11 IEs out of 340 thyroid FNAs followed by surgical resection. Five benign follicular nodules (BFNs) were misinterpreted as suspicious for carcinoma. Focal nuclear atypia in cyst-lining or follicular cells and a monotonous population of macrophages misinterpreted as Hurthle cells (HCs) were the causes of IEs in this category. Four Hashimoto’s thyroiditis (HT) cases were misinterpreted as suspicious for malignancy. Innate atypia of HCs and sampling misinterpretation were the causes of IEs in HT. One medullary and 1 follicular carcinoma were misinterpreted as suspicious for follicular neoplasm and BFN, respectively. Nine cases were better classified after review. <b><i>Conclusion:</i></b> Thyroid FNA IEs can be mitigated by meticulous screening and identification of all elements on FNA smears. Awareness of focal nuclear atypia in reactive cyst-lining and follicular cells in BFN, as well as HCs in HT, is highlighted. Adherence to The Bethesda System for Reporting Thyroid Cytopathology and consulting experienced cytopathologists significantly decrease IEs.

Giant complex non-parasitic splenic cyst in a young boy: is laparoscopic spleen-preserving surgery safe?

Non-parasitic splenic cysts are an uncommon finding in pediatric patients. We report on a 14-year-old male presenting with a giant abdominal mass. Imaging documented a giant splenic cyst, and preoperative blood tests revealed high levels of CA125. Minimally invasive unroofing of the cyst was performed. Notably, the cyst content was hematic, but histopathological studies described a mesothelial cyst lining. To date, no recurrence has been noted. Laparoscopic spleen-preserving surgery appears to be a valid and safe treatment option in children with complex non-parasitic splenic cyst to preserve the splenic parenchyma.

Smoking accelerates renal cystic disease and worsens cardiac phenotype in Pkd1-deficient mice

Smoking has been associated with renal disease progression in ADPKD but the underlying deleterious mechanisms and whether it specifically worsens the cardiac phenotype remain unknown. To investigate these matters, Pkd1-deficient cystic mice and noncystic littermates were exposed to smoking from conception to 18 weeks of age and, along with nonexposed controls, were analyzed at 13–18 weeks. Renal cystic index and cyst-lining cell proliferation were higher in cystic mice exposed to smoking than nonexposed cystic animals. Smoking increased serum urea nitrogen in cystic and noncystic mice and independently enhanced tubular cell proliferation and apoptosis. Smoking also increased renal fibrosis, however this effect was much higher in cystic than in noncystic animals. Pkd1 deficiency and smoking showed independent and additive effects on reducing renal levels of glutathione. Systolic function and several cardiac structural parameters were also negatively affected by smoking and the Pkd1-deficient status, following independent and additive patterns. Smoking did not increase, however, cardiac apoptosis or fibrosis in cystic and noncystic mice. Notably, smoking promoted a much higher reduction in body weight in Pkd1-deficient than in noncystic animals. Our findings show that smoking aggravated the renal and cardiac phenotypes of Pkd1-deficient cystic mice, suggesting that similar effects may occur in human ADPKD.

Functional megalin is expressed in renal cysts in a mouse model of adult polycystic kidney disease

Background Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the progressive growth of cysts and decline of renal function. The clinical feasibility of a number of potential disease-modifying drugs is limited by systemic, adverse effects. We hypothesize that megalin, a multi-ligand endocytic receptor expressed in the proximal tubule, may be used to facilitate drug uptake into cysts, thereby allowing for greater efficacy and fewer side effects. Methods The cyst expression of various tubular markers including megalin and aquaporin 2 (AQP2) was analyzed by immunohistochemistry (IHC) of kidney sections from the ADPKD mouse model (PKD1RC/RC) at different postnatal ages. The endocytic function of megalin in cysts was examined by IHC of kidney tissue from mice injected with the megalin ligand aprotinin. Results Cyst lining epithelial cells expressing megalin were observed at all ages; however, the proportion decreased with age. Concomitantly, an increasing proportion of cysts revealed a partial expression of megalin, expression of AQP2 or no expression of examined markers. Endocytic uptake of aprotinin was evident in megalin positive cysts, but only in those that remained connected to the renal tubular system. Conclusions Megalin expressing cysts were observed at all ages, but the proportion decreased with age possibly due to a switch in tubular origin, a merging of cysts of different tubular origin and/or a change in the expression pattern of cyst lining cells. Megalin expressed in cysts was functional suggesting that megalin-mediated endocytosis is a potential mechanism for drug targeting in ADPKD if initiated early in the disease.

Changes in Cellular Regulatory Factors before and after Decompression of Odontogenic Keratocysts

Decompression followed by enucleation, which is one of the treatments used for odontogenic keratocysts (OKCs), is frequently used in OKC lesions of large sizes. This method offers the advantage of minimizing the possibility of sensory impairment without creating a wide-range bone defect; moreover, the recurrence rate can be significantly lower than following simple enucleation. This study aimed to assess the changes in histology and expression of proliferation markers in OKCs before and after decompression treatment. A total of 38 OKC tissue samples from 19 patients who had undergone decompression therapy were examined morphologically and immunohistochemically to observe changes in proliferative activity before and after decompression. The markers used for immunohistochemistry (IHC) staining were Bcl-2, epidermal growth factor receptor (EGFR), Ki-67, P53, PCNA, and SMO. The immunohistochemistry positivity of the 6 markers was scored by using software ImageJ, version 1.49, by quantifying the intensity and internal density of IHC-stained epithelium. The values of Bcl-2, Ki-67, P53, proliferating cell nuclear antigen (PCNA), and SMO in OKCs before and after decompression showed no significant change. No correlation between clinical shrinkage and morphologic changes or expression of proliferation and growth markers could be found. There was no statistical evidence that decompression treatment reduces potentially aggressive behavior of OKC within the epithelial cyst lining itself. This might indicate that decompression does not change the biological behavior of the epithelial cyst lining or the recurrence rate.

Residual cyst of the jaws: A clinico-pathologic study of this seemingly inconspicuous lesion

Objectives Residual cysts are relatively rare inflammatory cysts of the jaws. They are essentially radicular cysts without the presence of the offending dentition. These lesions have the ability to destroy bone within the jaws without any symptoms. Moreover, they can mimic more aggressive cysts and tumours on radiographs. The aim of this study was to describe the clinico-pathological features of residual cysts in order to discern them from other cystic lesions as well as analyse their management and recurrence patterns. Materials and methods Sixty-four histopathologically confirmed residual cysts were analysed based on their clinical, radiological and histopathological features. Their management and follow-up were also noted. Results The majority of lesions presented in elderly (46.8%), edentulous patients (60.9%) and were most commonly found in the posterior regions of the mandible (51.6%). Clinico-pathological features that aided in their diagnosis included long-standing history with slow growing swelling and presence of well-defined, unilocular cystic lesion associated with previously extracted dentition. Enucleation was a successful method in the management of residual cysts with very low recurrence rate (1.6%). Two patients (3.1%) developed squamous cell carcinoma from the cyst lining. Conclusion Residual cysts should be high on the list of differential diagnosis when elderly, edentulous patients present with cystic lesions in the jaws compared to dentate patients (P<0.01). All lesions should by biopsied and sent for histopathological examination along with radiological correlation as they have the potential to transform into primary intra-osseous squamous cell carcinoma with devastating consequences to the patient.

Uncommon Coetaneous Histopathological Findings in Radicular Cyst: A Case Report

Radicular cyst is the most common inflammatory cyst of jaw. It arises from the epithelial residues in the periodontal ligaments as a result of pulp infection. Histopathologically radicular cyst lining reveals stratified squamous epithelium with arcade like pattern in early cases or quiescent epithelial lining in long standing cases. The wall of the radicular cyst is fibrous with mixed inflammatory cells infiltrate like neutrophils, plasma cells, lymphocytes and macrophages. There are very few reported cases of juxtaepithelial hyalinization of radicular cyst. Here we report a case of radicular cyst of a 28 year old male who presented with pus discharge from anterior right maxillary region. The cyst was associated with atrophic and tenuous epithelial lining with juxtaepithelial hyalinization along with focal Russell bodies. These findings are uncommoncoeval features of radicular cyst.

IFT-A deficiency in juvenile mice impairs biliary development and exacerbates ADPKD liver disease

Polycystic liver disease (PLD) is characterized by the growth of numerous biliary cysts and presents in patients with Autosomal Dominant Polycystic Kidney Disease (ADPKD), causing significant morbidity. Interestingly, deletion of intraflagellar transport-B (IFT-B) genes in adult mouse models of ADPKD attenuates severity of PKD and PLD. Here we examine the role of deletion of IFT-A gene, Thm1, in PLD of juvenile and adult Pkd2 conditional knock-out mice. Perinatal deletion of Thm1 results in disorganized and expanded biliary regions, biliary fibrosis, shortened primary cilia on CK19+ biliary epithelial cells, and reduced Notch signaling. In contrast, perinatal deletion of Pkd2 causes PLD, with multiple CK19+ biliary epithelial cell-lined cysts, fibrosis, lengthened primary cilia, and increased Notch and ERK signaling. Perinatal deletion of Thm1 in Pkd2 conditional knock-out mice increased hepatomegaly and liver necrosis, indicating enhanced liver disease severity. In contrast to effects in the developing liver, deletion of Thm1 in adult mice, alone and together with Pkd2, did not cause a biliary phenotype nor affect Pkd2-mutant PLD, respectively. However, similar to juvenile PLD, Notch and ERK signaling were increased in adult Pkd2-mutant cyst-lining cholangiocytes. Taken together, Thm1 is required for biliary tract development, likely by enabling Notch signaling, and proper biliary development restricts PLD severity. Unlike IFT-B genes, Thm1 does not affect hepatic cystogenesis, suggesting divergent regulation of signaling and cystogenic processes in the liver by IFT-B and –A. Notably, increased Notch signaling in cyst-lining cholangiocytes may indicate that aberrant activation of this pathway promotes hepatic cystogenesis, presenting as a novel potential therapeutic target.