Search

Coronavirus disease 2019 (COVID-19), a mystified cryptic virus has challenged the mankind that has brought life to a standstill. Catastrophic loss of life, perplexed healthcare system and the downfall of global economy are some of the outcomes of this pandemic. Humans are raging a war with an unknown enemy. Infections, irrespective of age and gender, and more so in comorbidities are escalating at an alarming rate. Cardiovascular diseases, are the leading cause of death globally with an estimate of 31% of deaths worldwide out of which nearly 85% are due to heart attacks and stroke. Theoretically and practically, researchers have observed that persons with pre-existing cardiovascular conditions are comparatively more vulnerable to the COVID-19 infection. Moreover, they have studied the data between less severe and more severe cases, survivors and non survivors, intensive care unit (ICU) patients and non ICU patients, to analyse the relationship and the influence of COVID-19 on cardiovascular health of an individual, further the risk of susceptibility to submit to the virus. This review aims to provide a comprehensive particular on the possible effects, either direct or indirect, of COVID-19 on the cardiovascular heath of an individual.

Background This study aimed to examine the cellular components of the gingiva during orthodontic treatment with fixed and removable appliances. The cellular and molecular cues of pathologies of the gingival tissue associated with the use of different orthodontic appliances could be studied. Materials and methods Tissue samples of gingiva were received from healthy patients undergoing gingivectomy for aesthetic purpose and from patients with fixed and removable functional orthodontic appliances undergoing gingivectomy for gingival overgrowth. The collected samples were stored in a sterile container with phosphate-buffered saline and to carry out further processes it was transported to the laboratory. Results Cells positive for ECAD and NCAD were found to be increased in fixed appliances where as CD90 and CD105 positive cells showed no significant difference in all the three groups. CD24 and CD146 positive cells were increased significantly in removable and fixed than normal whereas CD133 positive cells were decreased in removable and fixed than normal. CD44 positive cells showed no noticeable change in all three groups. The gene expression levels of KRT5, SOX2, NANOG, and CXCL5 were found to be significantly increased in removable and fixed appliance groups. However, KRT8, CXCL10, and TIMP1 were increased only in fixed appliance group but CXCL10 showed decreased expression in removable appliance group. KRT6A, MYC, and MMP9 were decreased in fixed appliance group whereas MYC and MMP9 were increased in removable appliance group. KRT6A, KRT8, and TIMP1 showed no significant difference in removable appliance group. Conclusion This study demonstrated essential roles of various genes, showing their contribution in regulating cell proliferation and migration in both the removable and fixed functional appliances.

Introduction: A method called sediment cytology includes the investigation of smears arranged from the sediment of the biopsy specimen fixatives. The sediment from this fixative is used to prepare smears and provides a potentially rich source for cytological material. Investigation of the fixative sediment and understanding of the cytological picture with pertinent clinical and radiological information permits diagnosis in a few hours. Aim: To evaluate the diagnostic efficacy of sediment cytology and oral brush cytology compared with histopathological findings in oral leukoplakia (OL) cases. Methods: Cytological smears were obtained from 30 clinically diagnosed OL lesions using 2 techniques: oral cytobrush and 10% formalin fixative sedimentation. Both smears were stained with Papanicolaou. Cytological smear evaluation was conducted with respect to cellularity, cell distribution, cellular clumping, and the presence of blood, debris, inflammatory cells, and microbial colonies. The cytopathological scores for all cases were compared between sediment and brush cytology and correlated with the histopathological diagnosis. For statistical analysis, the κ test and the Wilcoxon matched-pair test were used. Results: The cytobrush technique had a sensitivity of 83.3% for OL cases histopathologically diagnosed as severe dysplasia, while the sediment cytology technique had a sensitivity of 16.6%. For moderate/mild dysplasia cases, the cytobrush technique had a sensitivity of 7.7%, whereas the sediment technique showed no diagnostic sensitivity. Conclusion: Based on the results from the present study, sediment cytology, unlike oral brush cytology, is not a useful screening tool for the preliminary diagnosis of potentially malignant oral lesions.

Background Periodontitis is a persistent polymicrobial infection, which leads to chronic inflammation in the tooth supporting tissues. Aggregatibacter actinomycetemcomitans are normal commensals of oral cavity but are low in number in periodontally healthy subjects. They are one of the major pathogens aetiologically linked to periodontal disease. Plasma and salivary antibody measurement may be useful to support diagnosis, disease activity, classification and prognosis of periodontitis. The aim of the present study was to investigate the association between the serum and salivary antibody levels to A. actinomycetemcomitans and therefore, to find whether this association was varying in different grades of periodontitis. Method Total of 50 periodontally healthy and 50 chronic periodontitis subjects (35–65 years) of both sexes were included for the study. 2 ml of un-stimulated saliva and 5 ml of venous blood was collected under sterile conditions. The detection of antibodies against A. actinomycetemcomitans in periodontally healthy individuals and individuals with chronic periodontitis was performed using indirect ELISA. Results Results showed serum IgG, IgA mean levels against A. actinomycetemcomitans were higher in chronic periodontitis subjects compared to mean levels in periodontally healthy subjects. Similarly, salivary IgG, IgA levels were also raised in chronic periodontitis patients as compared in healthy subjects. Also the mean levels of serum IgG and salivary IgA were increased as the severity of disease increased. Conclusion Antibody titer using saliva and serum could be useful tool for screening of patients with chronic periodontitis. Further, monitoring the various phases of treatment outcome using saliva could be a useful, non-invasive, prognostic indicator.

Background and Objectives: Oral cancer is the 6th most common cancer in the world and oral leukoplakia is an oral potentially malignant disorder that could develop into oral cancer. This systematic review focusses on randomized clinical trials for recombinant adenovirus p-53 (rAD-p53) therapy for the treatment of oral leukoplakia and cancer. Materials and Methods: We searched for research articles on various databases such as Pubmed/Medline, Embase, CNKI (China National Knowledge Infra-structure), Springerlink, cochrane and Web of sciences from 2003 to 2020. MeSH (Medical Subject Headings) terms were used for the search. Inclusion criteria included original research, randomized clinical trials and articles only in English language. Exclusion criteria were any articles that were not research articles, not randomized trials, non-human studies, etc. The articles were further graded on the Jadad scale. Results: 578 articles were assessed from various databases; only 3 articles were found to be appropriate for this review. Thus, meta-analysis was not performed because of heterogeneity and lack of data. In the three studies, whether rAD-p53 was used as a standalone therapy or with other therapies, there was a beneficial effect of the therapy. Furthermore, there were no serious adverse events and the only adverse events reported were fever, pain at the local injection site, flu-like symptoms and lowered WBC count. Conclusions: Thus, we can conclude that this therapy has a potential for beneficial therapeutic effects and further clinical trials with more patients need to be performed to get better understanding of the effect of rAD-p53 therapy, which probably will pave the way to its approval in other parts of the world.

An estimated 4% of all cancers are of the oral cavity or oropharyngeal. Presently, management of the oral cancers mainly includes surgery, radiotherapy, and chemotherapy either alone or in combination depending on the individual case. Each of these techniques has their advantages and disadvantages. Surgery demands removal of cancerous tissue causing disfigurement and functional impairment. Radiotherapy has significant side effects like mucositis, myelosuppression, xerostomia and dental caries. With the advent of newer treatment methods like the targeted therapy, immune therapy and gene therapy, treatment outcomes are better with fewer side effects. This has generally improved survival rates and quality of life of cancer patients.

Oral squamous cell carcinoma (OSCC) is most common oral cancer with multifactorial etiology. Surgical therapy is treatment of choice but known to have recurrence. The main reason for recurrence is associated with surgical margins which need to be tumor free. Changes at genetic level cannot be ascertained only through routine light microscopy in surgical margins, even though they are tumor free. Detection of early marker like p16 can help in predicting the risk of recurrence. Hence study aimed to detect p16 microsatellite marker (D9s1747) in surgical margins of oral squamous cell carcinoma and compare the same with p16 marker through immunohistochemistry. Total of 40 paraffin embedded tissue samples diagnosed and surgically treated cases of OSCC were included. From each sample one tumor proper and one surgical margin was obtained. From paraffin embedded tissue sample 2 sections of 4 µm thick was obtained from tumor proper and tumor margin. One section was stained with hematoxylin and eosin and other section was stained immunohistochemically using p16 antibody. DNA extraction was done for tumor proper and surgical margin tissue and PCR analysis was carried for p16 microsatellite marker (D91747). Out of 40 cases 37 cases showed positivity in tumor proper for p16 with IHC. Out of 37 cases 23 cases showed positivity for both tumor proper and surgical margin. There were 3 cases negative for tumor proper. Out of these 3 cases, 1 (33.3%) case was positive for surgical margin. Out of 40 cases 27 cases showed positivity for tumor proper with p16 microsatellite marker. Out of 27 cases 16 cases showed positivity for both tumor proper and surgical margin. There were 13 cases negative for tumor proper. However there were 8 (61.5%) cases negative which were in tumor proper but showed positivity for surgical margin. Other 5 cases were negative in both tumor proper and surgical margin. Our study reveals that surgical margins of OSCC exhibit alteration in p16 markers both by IHC and PCR techniques. p16 and p16 microsatellite marker detection in margins indicates field change. Further studies with larger sample size comparing expression with clinical and histological parameter and follow up has to be done to substantiate our findings.

Background Photobiomodulation therapy, a non invasive method with no adverse effects, has been used to accelerate tooth movement in orthodontia. However, the specific characteristics of laser settings used in studies documented have reported varied inconsistent conflicting results. Objectives We decided to undertake a systematic review to eliminate this inconsistency by quantifying the literature studies that indicated the link between photobiomodulation and acceleration of tooth movement and to assess if there is any association of photobiomodulation therapy in accelerating tooth movement. Search strategy We systematically searched for articles of existing literatures on Photobiomodulation therapy and acceleration of tooth movement over Cochrane library, Pubmed central, EMBASE, Scopus and Web of sciences from 2000 to 2017. Mesh search terms using various descriptors were used to identify the studies. Search criteria We included randomized control trial and clinical control trail studies that used Ga-Al-As diode laser and Oseeopulse laser with specific characteristics and company specifications, addressing relevant efficiency and safety outcomes. Data collection and analysis Eligible studies were reviewed and data was extracted on a standard from. We used Cochrane review manager software (Revman version 5.3) to assess the qualities of each included trials. Data were analyzed using an inverse variance method with random effects model effect. Results We observed a statistical significant difference between the photobiomodulation therapy compared to non laser group in the acceleration of tooth movement (Mean difference 0.59 (95%CI- 0.24 to 0.95) I2 95%). However, these results need caution while generalizing in clinical practice due to the large amount of heterogeneity across the studies. Conclusion Findings of the current systematic review suggest a possible benefit with photobiomodulation therapy and tooth movement in orthodontia. However these findings need to be further validated in larger trials using specific standardized characteristics of laser settings to uniform the methodological design that can be used in routine clinical practice.

Dental plaque is a biofilm that forms naturally on the surfaces of exposed teeth and other areas of the oral cavity. It is the primary etiological factor for the most frequently occurring oral diseases, such as dental caries and periodontal diseases. Specific, nonspecific, and ecologic plaque hypothesis explains the causation of dental and associated diseases. Adequate control of biofilm accumulation on teeth has been the cornerstone of prevention of periodontitis and dental caries. Mechanical plaque control is the mainstay for prevention of oral diseases, but it requires patient cooperation and motivation; therefore, chemical plaque control agents act as useful adjuvants for achieving the desired results. Hence, it is imperative for the clinicians to update their knowledge in chemical antiplaque agents and other developments for the effective management of plaque biofilm-associated diseases. This article explores the critical analysis of various chemical plaque control strategies and the current trends in the control and prevention of dental plaque biofilm. How to cite this article Jafer M, Patil S, Hosmani J, Bhandi SH, Chalisserry EP, Anil S. Chemical Plaque Control Strategies in the Prevention of Biofilm-associated Oral Diseases. J Contemp Dent Pract 2016;17(4):337-343.

Background: Cytogenetic studies from past decades have shown that interphase cells of female cats contain a densely stained chromatin mass in their nuclei called as Barr bodies (BBs) named after the scientist Murray Barr. BBs are unique chromatin structures formed due to the condensation of the X-chromosome. Many psychopathic disorders originate from defective genes including the multiple X syndromes. Males with extra X-chromosome generally present with severe personality disorder. The present study was conducted to determine the presence of extra X-chromosome in male jail inmates through the detection of BB in peripheral blood and buccal smear. Materials and Methods: Study included 100 male subjects (fifty jail inmates and fifty controls), after obtaining the consent, peripheral blood smears (PBS) and buccal smears (BS) were prepared and stained using Leishman's and cresyl violet stain respectively. One hundred neutrophils in PBS and epithelial cells in BS were screened for detection of the BB; accumulated data were tabulated and statistically analyzed using t-test and Chi-square test. Results: 60% of cases in PBS and 36% in BS showed positivity for the presence of BB in jail inmates as compared to 14% of cases in PBS and none in BS were positive for BB in controls. Conclusion: Presence of BB in male suggests increased likelihood of criminal tendencies. Further studies are to be carried out to compare the results with karyotyping.

Oral fibroblasts, similar to dermal fibroblasts, have the potential to resist the local insults like trauma to the oral mucosa by differentiating into adipocytes and secreting antimicrobial peptide cathelicidin (Camp) and this physiologic process in known as reactive adipogenesis. We hypothesize that in oral submucous fibrosis (OSF), due to constant secretion and up-streaming of transforming growth factor-beta (TGF- β), oral fibroblast lose their adipogenic differentiation potential and Camp production, which leads to progressive fibrosis in OSF. The implication of this hypothesis could open some promising vistas on still unexplored innate immune systems harboured by oral mucosa. Restoring and maintaining the adipogenic and protective potential of oral fibroblasts by inhibiting TGF- β receptors could hinder the disease progression of OSF.

Background External stressors such as high altitude and low oxygen are known to affect the human microbiome, and in light of the increased occurrence of dental caries and periodontitis in orthodontic patients, the effect of high altitude and the altered oral environment in orthodontic patients on the oral salivary microbiome was researched. Materials & methods 31 orthodontic patients from high altitude, Aseer region and 25 orthodontic patients, residing at sea level, as controls were included. DNA isolation was done from the saliva collected from the study participants. V3 area of 16s RNA was targeted by universal primers through PCR to decipher the salivary microbiome in both the groups. Results A total of 11 genera belonging to 4 phyla of bacteria were identified in both groups. The most abundant microbiome at the phylum level was: Firmicutes, Bacteroidetes Proteobacteria, and Cyanobacteria. The salivary microbiome was more diverse in sea level controls compared to that of the orthodontic patients at high altitude wherein the presence of only two main phyla: Firmicutes and Proteobacteria were seen. The controls revealed Firmicutes, Proteobacteria, Bacteroidetes and Cyanobacteria. Conclusions The findings of the study suggest that the biodiversity of the salivary microbiome is severely perturbed under the cumulative influences of high altitude and presence of fixed orthodontic appliance. Under these circumstances, a strict and meticulous oral hygiene regimen should be recommended and followed to avoid harmful effects on the periodontal tissues.

The present review summarizes the current updates on dental perspectives on leprosy and the affording factors that are responsible for the prevalence of caries and periodontal diseases in leprosy. It also highlights immunopathological phenomena and reactional episodes of leprosy that occur due to daedal interactions between the perio-odontopathic bacteria and M. leprae. In addition, a brief introduction, historiography, classification and clinicopathological aspects are also been covered.

Objectives: To compare immunohistochemical expression of CD34 and CD105 in oral submucous fibrosis (OSF) and normal oral mucosa (NOM) and correlate with clinicopathological features of OSF. Materials and Methods: Total of thirty clinically diagnosed and histologically confirmed cases of OSF and 15 NOM were included in the study. Tissues sections were immunostained using CD34 and CD105 antibodies. Results: Twenty-eight cases (93.33%) were positive for CD34, and only 12 cases (40%) were positive for CD105 in OSF. In NOM all cases were positive for CD34 and only one case was positive for CD105. CD34 and CD105 significantly expressed in moderately advanced OSF when compared to very early, early, and advanced cases. It was found that the microvessel density (MVD) in NOM was significantly higher as compared to OSF and MVD decreased with advanced OSF. MVD was higher in CD34 when compared to CD105. MVD decreased with disease progression in OSF using both the markers. Conclusion: The role of CD34 in determining the premalignant nature of OSF could not be ascertained, since all endothelial cells were positive for CD34, whereas CD105 appeared to be more specific as it is associated with hypoxia-induced angiogenesis which is occurring in OSF due to hyalinization suggesting, CD105 to be more specific marker to determine neoangiogenesis in OSF. Thus further follow-up study of the cases positive for CD105 is required to determine the true nature of angiogenesis in OSF patients.

Objectives: Compare and correlate immunoexpression of vascular endothelial growth factor (VEGF) and CD105 in oral squamous cell carcinoma (OSCC), and correlate its expression with the prognosis of the patient. Materials and Methods: A retrospective study was carried out on total of 49 cases of OSCC. Detailed demographic and clinical data were obtained, and tissue sections were stained with hematoxylin and eosin to grade the tumor. Later each case was subjected for immunohistochemical analysis of CD105 and VEGF. Results: All the cases showed positivity for both CD105 and VEGF but high expression was noted with CD105 compared to VEGF. Average microvascular density for CD105 was higher (69.5) in moderately differentiated squamous cell carcinoma (MDSCC) when compared to well differentiated squamous cell carcinoma (WDSCC) (52.16). When expression of CD105 and VEGF was compared in WDSCC and MDSCC, it was statistically insignificant. However when expression of CD105 and VEGF was compared with survival of the patient, survival rate was

The major cancer therapeutic modalities include surgery, chemotherapy and radiotherapy. Although these treatment regimens have played a significant role in effectively inhibiting cancer, their associated morbidity reduces the overall quality of life. Thus, researchers are striving to identify any alternate therapeutic approach capable of inhibiting cancer without eliciting the added morbidity. Among the alternate cancer therapeutics being researched, much importance is being given to the use of plants due to the presence of a wide variety of anti-carcinogenic compounds. Tinospora cordifolia (Tc) is one such plant and has shown to exhibit anti-carcinogenic properties. The present review aimed to systematically analyze published data on the effect of Tinospora cordifolia-derived phytocomponents on cancer. PubMed, Scopus, Web of Science, Embase and Cochrane library were searched using the keywords Tinospora cordifolia; anticancer; phytocomponents until March 20, 2019. In vivo and in vitro original studies in the English language were included. Of the 342 articles identified, only 25 articles met the selection criteria and were included in the review. Significant anti-carcinogenic properties were exhibited by Tinospora cordifolia-derived phytocompounds including palmative, berberine, new clerodane furanoditerene glycoside, arabinogalactan, phenolic compounds and epoxy cleodane diterpene. No significant side effects have been elicited with its use. Based on the data from the included studies, Tinospora cordifolia could be a natural therapeutic agent for cancer, provided its anti-carcinogenic properties can be elicited consistently at a large scale in clinical trials.

Aim: Studies have been done in diversified population, demonstrating the uniqueness of frontal sinus; data related to the Indian population are less. Thus, the present study was aimed to determine the frontal sinus measurement and to assess its forensic application in the Indian population. Materials and Methods: A total of 400 individuals with Indian origin (21–30 years) were included in the study. The digitized posteroanterior skull radiographs were obtained and was transferred to Adobe® CS4 extended to measure the dimensions of frontal sinus and orbit for 12 parameters. Statistical Analysis: A descriptive statistical analysis was performed. Results: The descriptive statistics showed the presence of bilateral frontal sinus in 87.7% and bilateral absence in 8.0% of the individuals and the absence of left and right frontal sinus in 3.3% and 1%, respectively. Maximum population showed high asymmetry index (64.7%); the right side frontal sinus (height, 59.3% and width, 40.8%) was superior to the left side in both males and females. The partial septa among the Indian population were absent for maximum population (55.2%), and supraorbital cells of the frontal sinuses were present on both sides among the Indian population. Conclusion: The observation of the present study suggests that the frontal sinus is highly asymmetrical and unique to the individual and hence can be effectively used in personal identification method in forensic anthropology.

Juvenile ossifying fibroma (JOF) is a highly aggressive uncommon fibro-osseous lesion occurring in the facial bones. Two histological variants of JOF, i.e. trabecular and psammomatoid have been reported. Here we present a case of a 20-year-old juvenile diabetic patient with massive growth on her left side of the jaw which was diagnosed as juvenile ossifying fibroma. This huge aggressive mass in the left side of the mandible had lead to complete lingual tilting of molars and premolars. After clinical and radiological examination, a biopsy led to the histopathological diagnosis of mixed variant of juvenile ossifying fibroma. The required surgical treatment (hemimandibulectomy) was undertaken under GA. The aggressive local behavior and high recurrence rate of JOF emphasizes the need for an early diagnosis, and appropriate radical treatment with long-term follow-up. One such case is reviewed and discussed in detail in the following article.

Toll-like receptors (TLRs) play an essential role in the activation of innate immunity. TLRs are expressed in B-lymphocytes, monocytes, dendritic cells and epithelial cells. We examined the immunohistochemical expressions of TLR4 and TLR9 in various grades of oral epithelial dysplasia (OED), oral squamous cell carcinoma (OSCC) and normal oral mucosa (NOM) to determine the association between TLR4 and TLR9 in the progression of lesions from dysplasia to carcinoma. Expressions of TLR4 and TLR9 were assessed using immunohistochemistry (IHC) on paraffin embedded tissue blocks of various grades of OED (28 cases), OSCC (27 cases) and NOM (10 cases). Expression of TLR4 was high in all grades of OED and OSCC. Expression of TLR9 was high in well differentiated squamous cell carcinoma and moderately differentiated squamous cell carcinomas, and moderate to low in poorly differentiated squamous cell carcinomas. Although expression was high in case of TLR4, it was not statistically significant. Expression of TLR9 was statistically significant. In OED, expression of TLR9 was less than that of TLR4. Our results indicated that the pattern of expression of TLR4 and TLR9 increased significantly from mild to severe dysplasia compared to controls. Expression of TLR4 and TLR9 reflects progression of OED to OSCC, which suggests that TLR may play a role in tumorigenesis and that it could be used as a target for OSCC prevention and therapy in the future.

Dental anatomy is the study of morphology of various teeth in human dentitions. The application of dental anatomy in clinical practice is important, and dentist should have a thorough knowledge regarding the morphology of the teeth. At times as a result of genetic variation, environmental factors, diet of an individual and race, variations in the morphology of the teeth can be observed. These variations have been extensively studied by the researcher in the field of anthropology to define a particular race. The most commonly observed changes include peg-shaped laterals, shovel-shaped incisors, and extra cusp on molar. Common variations documented with regard to maxillary and mandibular first premolars are the variation in the number of roots. But the variations with respect to crown morphology are few. We report a first documented unusual presentation of maxillary and mandibular first premolars with three-cusps pattern in a female patient.

Laugier-Hunziker syndrome is a rare acquired disorder characterized by diffuse hyperpigmentation of the oral mucosa and longitudinal melanonychia in adults. They appear as macular lesions less than 5 mm in diameter. Laugier-Hunziker syndrome is considered to be a benign disease with no systemic manifestation or malignant potential. Therefore, it is important to rule out other mucocutaneous pigmentary disorders that do require medical management. Prompt clinical recognition also averts the need for excessive and invasive procedures and treatments. In India, the reported cases of this syndrome are very few. We provide a review of literature on Laugier-Hunziker syndrome with its differential diagnosis.

Lymphangioma is a benign, hamartomatous tumor of the lymphatic system. It is usually found in the head and neck region and is widely regarded as a developmental lesion rather than a true neoplasia. Most lymphangiomas are present at birth. In head and neck area, the most common location is the submandibular region, followed by the parotid gland. When lymphangioma occurs in the oral cavity, the anterior two third of the tongue is most commonly affected. The occurrence of lymphangioma in other parts of the oral cavity is very uncommon. Here, we report an unusual case of lymphangioma of buccal mucosa in a 45-year-old female.

Fine needle aspiration cytology (FNAC) has been employed with increasing frequency as a diagnostic tool for lesions of the major and minor salivary glands. The reported sensitivity and specificity of FNAC of salivary gland lesion ranges approximately between 60 and 100% and 90 and 100%, respectively. The major reason for varied statistics in diagnosis is due to its diverse morphological patterns and overlapping features that makes it a challenging job for pathologists to give a precise diagnosis. If established diagnostic criteria are present and strictly followed, a great majority of common variations of non-neoplastic lesions, benign and malignant salivary gland tumors can be diagnosed with high level of accuracy with FNAC. A patient with high operation risk may benefit from the information obtained by FNAC. We report a case of adenoid cystic carcinoma of maxillary sinus in a 46-year-old male patient diagnosed mainly through FNAC and also discuss the possible differential diagnosis and pitfalls of FNAC in diagnosing adenoid cystic carcinoma.