Early diagnosis of renal pelvis villous adenoma:A case report

BACKGROUND Villous adenoma is a rare tumor in the urinary system that usually occurs in the bladder.It is extremely uncommon in the renal pelvis.Most of the previously reported cases have been diagnosed with severe hydronephrosis associated with renal parenchyma atrophy prior to surgery.Because of its rarity,available information on the pathogenesis,diagnosis,treatment and prognosis of the disease is limited.We reported a case of kidney stones with hydronephrosis.During percutaneous nephroscopic lithotripsy,a renal pelvis tumor was found.Biopsy confirmed that the tumor was a villous adenoma of the renal pelvis.CASE SUMMARY A 68-year-old female was admitted to the hospital due to right kidney stones with right hydronephrosis.After admission,a urinary system plain computed tomography scan was performed,which revealed right kidney stones with right hydronephrosis and right upper ureteral dilatation.Multiple new cauliflower-like papillary masses were then discovered in the renal pelvis and calyces during right percutaneous nephroscopic lithotripsy.Biopsy results indicated villous adenoma with high-grade glandular intraepithelial neoplasia.The patient underwent laparoscopic radical resection of the right kidney and ureter.Based on histopathological and immunohistochemical examination,the patient was diagnosed with villous adenoma without adenocarcinoma.CONCLUSION Villous adenoma is rare in the urinary system.We reported a case of renal pelvis villous adenoma,which may provide useful information for the early diagnosis and treatment of this tumor.

Coexistence of small cell neuroendocrine carcinoma and villous adenoma in the ampulla of Vater

Small cell neuroendocrine carcinoma of the ampulla of Vater is extremely rare and different from the common ampullary adenocarcinoma. The ampullary adenoma is also a rare neoplasm and has the potential to develop an adenocarcinoma. Their coexistence has been rarely reported in the literature. We herein describe an unusual case of a small cell neuroendocrine carcinoma associated with a villous adenoma in the ampulla of Vater with emphasis on computed tomography (CT) and histopathological findings. We also discuss their clinical, histopathological and radiological features as well as possible histogenesis.

Gallbladder villous adenoma in a patient with acromegaly:A case report

Villous adenomas are benign epithelial lesions with malignant potential that can occur in any part of the gastrointestinal tract. We present a case of a middle age woman with acromegaly who was investigated for nonspecific gastrointestinal complaints. Ultrasonography and subsequent endosonography diagnosed a large （4.5 cm）, hyperechoic, sessile polyp with numerous pedicles. An open cholecystectomy was performed and revealed a villous adenoma with several foci of carcinoma in situ. Detailed investigations showed no other tumors of the gastrointestinal tract. After five years of follo up, the patient reports no complaints, and the results of laboratory testing and imaging studies are within the normal range.

Long-term impact of artificial intelligence on colorectal adenoma detection in high-risk colonoscopy

BACKGROUND Improved adenoma detection rate(ADR)has been demonstrated with artificial intelligence(AI)-assisted colonoscopy.However,data on the real-world appli-cation of AI and its effect on colorectal cancer(CRC)screening outcomes is limited.AIM To analyze the long-term impact of AI on a diverse at-risk patient population undergoing diagnostic colonoscopy for positive CRC screening tests or sympt-oms.METHODS AI software(GI Genius,Medtronic)was implemented into the standard proced-ure protocol in November 2022.Data was collected on patient demographics,procedure indication,polyp size,location,and pathology.CRC screening outcomes were evaluated before and at different intervals after AI introduction with one year of follow-up.RESULTS We evaluated 1008 colonoscopies(278 pre-AI,255 early post-AI,285 established post-AI,and 190 late post-AI).The ADR was 38.1%pre-AI,42.0%early post-AI(P=0.77),40.0%established post-AI(P=0.44),and 39.5%late post-AI(P=0.77).There were no significant differences in polyp detection rate(PDR,baseline 59.7%),advanced ADR(baseline 16.2%),and non-neoplastic PDR(baseline 30.0%)before and after AI introduction.CONCLUSION In patients with an increased pre-test probability of having an abnormal colonoscopy,the current generation of AI did not yield enhanced CRC screening metrics over high-quality colonoscopy.Although the potential of AI in colonoscopy is undisputed,current AI technology may not universally elevate screening metrics across all situations and patient populations.Future studies that analyze different AI systems across various patient populations are needed to determine the most effective role of AI in optimizing CRC screening in clinical practice.

Superficial Serrated Adenoma (SuSA): A New Subtype of Serrated Lesions

Superficial serrated adenoma (SuSA) is a new subtype of serrated lesions proposed in recent years, most of which are located in the sigmoid colon or rectum, with typical mixed adenoma and serrated pathological features, and its molecular features are high frequency of KRAS mutation and RSPO fusion or overexpression. At present, it is believed that SuSA has two subtypes: traditional serrated adenoma (TSA)-associated SuSA and isolated SuSA. Solitary SuSA showed faded pedicle-free protuberant lesions under endoscope and lobulated, pp (pit pattern) classification was type II and type IIIH, TSA-associated SuSA showed double-layer eminence, SuSA part showed white flat eminence, pp classification showed type II and IIIH, TSA part showed red tone high eminence, pp was IVH type. SuSA can develop into colorectal cancer through the evolution of TSA, and it can also directly develop into MSS colorectal cancer. In view of the superficial understanding of SuSA and the lack of a complete description of SuSA, this paper review the research progress of SuSA at home and abroad from the origin, endoscope features, histopathological features, molecular biology, differential diagnosis and treatment of SuSA, in order to better promote the understanding and clinical diagnosis of lesions.

Dysbiosis and colonic adenoma: The lethal link?

Gut dysbiosis,a phenomenon in which the existing commensal microbiome cha-nges to an adverse microenvironment in the colon,is thought to lead to altered cellular signals.How this is involved in producing mucosal outgrowths such as polyps in the colon is intriguing.Deciphering the various mechanisms involved provides an in-depth understanding of the link between gut dysbiosis and colonic polyps.

miR-200b-3p accelerates progression of pituitary adenomas by negatively regulating expression of RECK

MicroRNA(miR)-200b-3p has been associated with many tumors,but its involvement in pituitary adenoma is unclear.This study investigated the molecular mechanism underlying miR-200b-3p regulation in pituitary adenomas to provide a theoretical basis for treatment.Bioinformatics was used to analyze pituitary adenoma-related genes and screen new targets related to RECK and miRNA.As well,the relationship between miR-200b-3p and RECK protein was verified using a double-luciferase reporter gene assay.The expression of miR-200b-3p in clinical samples was analyzed by in situ hybridization.Transfection of the miR-200b-3p inhibitor and small interfering-RECK(si-RECK)was verified by qPCR.GH3 cell viability and proliferation were detected using CCK8 and EdU assays.Apoptosis was detected by flow cytometry and western blotting.Wound healing and Transwell assays were used to detect cell migration and invasion.The effects of miR-200b-3p and RECK on GH3 cells were verified using salvage experiments.miR-200b-3p was highly expressed in pituitary tumor tissue.Inhibitors of miR-200b-3p inhibited cell proliferation promoted cell apoptosis,inhibited invasion and migration,and inhibited the expression of matrix metalloproteinases.Interestingly,miR-200b-3p negatively regulated RECK.The expression of RECK in pituitary adenoma tissues was lower than that in neighboring tissues.Si-RECK rescued the function of miR-200b-3p inhibitors in the above cellular behaviors,and miR-200b-3p accelerated the development of pituitary adenoma by negatively regulating RECK expression.In summary,this study investigated the molecular mechanism by which miR-200b-3p regulates the progression of pituitary adenoma through the negative regulation of RECK.The findings provide a new target for the treatment of pituitary adenoma.

Standard-definition White-light,High-definition White-light versus Narrow-band Imaging Endoscopy for Detecting Colorectal Adenomas:A Multicenter Randomized Controlled Trial

Objective This study aimed to compare the performance of standard-definition white-light endoscopy(SD-WL),high-definition white-light endoscopy(HD-WL),and high-definition narrow-band imaging(HD-NBI)in detecting colorectal lesions in the Chinese population.Methods This was a multicenter,single-blind,randomized,controlled trial with a non-inferiority design.Patients undergoing endoscopy for physical examination,screening,and surveillance were enrolled from July 2017 to December 2020.The primary outcome measure was the adenoma detection rate(ADR),defined as the proportion of patients with at least one adenoma detected.The associated factors for detecting adenomas were assessed using univariate and multivariate logistic regression.Results Out of 653 eligible patients enrolled,data from 596 patients were analyzed.The ADRs were 34.5%in the SD-WL group,33.5%in the HD-WL group,and 37.5%in the HD-NBI group(P=0.72).The advanced neoplasm detection rates(ANDRs)in the three arms were 17.1%,15.5%,and 10.4%(P=0.17).No significant differences were found between the SD group and HD group regarding ADR or ANDR(ADR:34.5%vs.35.6%,P=0.79;ANDR:17.1%vs.13.0%,P=0.16,respectively).Similar results were observed between the HD-WL group and HD-NBI group(ADR:33.5%vs.37.7%,P=0.45;ANDR:15.5%vs.10.4%,P=0.18,respectively).In the univariate and multivariate logistic regression analyses,neither HD-WL nor HD-NBI led to a significant difference in overall adenoma detection compared to SD-WL(HD-WL:OR 0.91,P=0.69;HD-NBI:OR 1.15,P=0.80).Conclusion HD-NBI and HD-WL are comparable to SD-WL for overall adenoma detection among Chinese outpatients.It can be concluded that HD-NBI or HD-WL is not superior to SD-WL,but more effective instruction may be needed to guide the selection of different endoscopic methods in the future.Our study’s conclusions may aid in the efficient allocation and utilization of limited colonoscopy resources,especially advanced imaging technologies.

In vivo pilot study into superficial microcirculatory characteristics of colorectal adenomas using novel high-resolution magnifying endoscopy with blue laser imaging

BACKGROUND No studies have yet been conducted on changes in microcirculatory hemody-namics of colorectal adenomas in vivo under endoscopy.The microcirculation of the colorectal adenoma could be observed in vivo by a novel high-resolution magnification endoscopy with blue laser imaging(BLI),thus providing a new insight into the microcirculation of early colon tumors.AIM To observe the superficial microcirculation of colorectal adenomas using the novel magnifying colonoscope with BLI and quantitatively analyzed the changes in hemodynamic parameters.METHODS From October 2019 to January 2020,11 patients were screened for colon adenomas with the novel high-resolution magnification endoscope with BLI.Video images were recorded and processed with Adobe Premiere,Adobe Photoshop and Image-pro Plus software.Four microcirculation parameters:Microcirculation vessel density(MVD),mean vessel width(MVW)with width standard deviation(WSD),and blood flow velocity(BFV),were calculated for adenomas and the surrounding normal mucosa.RESULTS A total of 16 adenomas were identified.Compared with the normal surrounding mucosa,the superficial vessel density in the adenomas was decreased(MVD:0.95±0.18 vs 1.17±0.28μm/μm2,P<0.05).MVW(5.11±1.19 vs 4.16±0.76μm,P<0.05)and WSD(11.94±3.44 vs 9.04±3.74,P<0.05)were both increased.BFV slowed in the adenomas(709.74±213.28 vs 1256.51±383.31μm/s,P<0.05).CONCLUSION The novel high-resolution magnification endoscope with BLI can be used for in vivo study of adenoma superficial microcirculation.Superficial vessel density was decreased,more irregular,with slower blood flow.

Pleomorphic adenoma(mixed tumor)of the upper lip:A case report

BACKGROUND Salivary gland tumors are relatively rare.Most minor salivary gland tumors are malignant with benign tumors accounting for 18%of the tumors.Pleomorphic adenoma(PA)is the most common salivary gland tumor.Lip PA is uncommon with 9.8%occurring in the upper lip.We are adding on the knowledge of the rare upper lip PA(benign mixed tumor).CASE SUMMARY We report an upper lip PA(benign mixed tumor)in a 28-year-old man.His complaint was a painless swelling on the upper lip.A painless,non-tender,well-circumscribed,slightly mobile,sessile,nodular,and rubbery(in consistency)tumor measuring 5.0 cm x 2.0 cm was noted on the left side of his upper lip.The overlying skin was not fixed and of normal color.There was no ulceration,and palpation did not elicit pain or bleeding.There was no history of trauma.Blunt dissection was used to completely excise the nodular,whitish,and encapsulated tumor.Microscopy showed a well-circumscribed and partly encapsulated biphasic lesion,with large lobules of myxo-chondroid stroma and intervening cellular nodules of basaloid cells,well-formed tubules containing eosinic secretion,and nests of myoepithelial cells.A diagnosis of PA(benign mixed tumor)was confirmed.CONCLUSION Blunt dissection is indicated to preserve the cosmesis and function of the upper lip.

Expression and significance of pigment epithelium-derived factor and vascular endothelial growth factor in colorectal adenoma and cancer

BACKGROUND The incidence and mortality of colorectal cancer(CRC)are among the highest in the world,and its occurrence and development are closely related to tumor neovascularization.When the balance between pigment epithelium-derived factors(PEDF)that inhibit angiogenesis and vascular endothelial growth factors(VEGF)that stimulate angiogenesis is broken,angiogenesis is out of control,resulting in tumor development.Therefore,it is very necessary to find more therapeutic targets for CRC for early intervention and later treatment.AIM To investigate the expression and significance of PEDF,VEGF,and CD31-stained microvessel density values(CD31-MVD)in normal colorectal mucosa,adenoma,and CRC.METHODS In this case-control study,we collected archived wax blocks of specimens from the Digestive Endoscopy Center and the General Surgery Department of Chengdu Second People's Hospital from April 2022 to October 2022.Fifty cases of specimen wax blocks were selected as normal intestinal mucosa confirmed by electronic colonoscopy and concurrent biopsy(normal control group),50 cases of specimen wax blocks were selected as colorectal adenoma confirmed by electronic colonoscopy and pathological biopsy(adenoma group),and 50 cases of specimen wax blocks were selected as CRC confirmed by postoperative pathological biopsy after inpatient operation of general surgery(CRC group).An immunohistochemical staining experiment was carried out to detect PEDF and VEGF expression in three groups of specimens,analyze their differences,study the relationship between the two and clinicopathological factors in CRC group,record CD31-MVD in the three groups,and analyze the correlation of PEDF,VEGF,and CD31-MVD in the colorectal adenoma group and the CRC group.The F test or adjusted F test is used to analyze measurement data statistically.Kruskal-Wallis rank sum test was used between groups for ranked data.The chi-square test,adjusted chi-square test,or Fisher's exact test were used to compare the rates between groups.All differences between groups were compared using the Bonferroni method for multiple comparisons.Spearman correlation analysis was used to test the correlation of the data.The test level(α)was 0.05,and a two-sided P<0.05 was considered statistically significant.RESULTS The positive expression rate and expression intensity of PEDF were gradually decreased in the normal control group,adenoma group,and CRC group(100%vs 78%vs 50%,χ^(2)=34.430,P<0.001;++~++vs+~++vs-~+,H=94.059,P<0.001),while VEGF increased gradually(0%vs 68%vs 96%,χ^(2)=98.35,P<0.001;-vs-~+vs++~+++,H=107.734,P<0.001).In the CRC group,the positive expression rate of PEDF decreased with the increase of differen-tiation degree,invasion depth,lymph node metastasis,distant metastasis,and TNM stage(χ^(2)=20.513,4.160,5.128,6.349,5.128,P<0.05);the high expression rate of VEGF was the opposite(χ^(2)=10.317,13.134,17.643,21.844,17.643,P<0.05).In the colorectal adenoma group,the expression intensity of PEDF correlated negatively with CD31-MVD(r=-0.601,P<0.001),whereas VEGF was not significantly different(r=0.258,P=0.07).In the CRC group,the expression intensity of PEDF correlated negatively with the expression intensity of CD31-MVD and VEGF(r=-0.297,P<0.05;r=-0.548,P<0.05),while VEGF expression intensity was positively related to CD31-MVD(r=0.421,P=0.002).CONCLUSION It is possible that PEDF can be used as a new treatment and prevention target for CRC by upregulating the expression of PEDF while inhibiting the expression of VEGF.

Pleomorphic Adenoma of the Salivary Glands: Two Atypical Locations

Pleomorphic adenoma is the most common tumor of the salivary glands, accounting for approximately 50% of salivary gland lesions. It develops mainly in the salivary glands: parotid (80%), submaxillary (10%), sublingual (1%) and in the accessory oral-pharyngeal glands (9%). The aim of this work was to report 2 cases of pleomorphic adenoma of atypical location and then to discuss the difficulties linked to its diagnostic and therapeutic management in the Malian context. They were a 40-year-old man and a 72-year-old woman. They were admitted to the ENT department of the “Luxembourg Mere-infant” hospital for oropharyngeal swelling for the first and swelling of the palate for the second. The clinical expression was a swelling in both cases, of a hard, mobile consistency with healthy mucosa on their surface. The remainder of the physical examination was unremarkable. The diagnosis of a tumor of the oropharynx and palate was made following clinical radiological examinations. The histopathological examination of the surgical specimen made it possible to make the diagnosis of pleomorphic adenoma of the palate and the left palatine tonsil. The follow-up surgery was straightforward, with a favorable outcome. Pleomorphic adenomas are relatively rare benign tumors of the accessory salivary glands;their clinical expression remains swelling. Therapeutic management is surgery and the diagnosis is confirmed by histopathological examination.

Current considerations for the surgical management of gallbladder adenomas

Gallbladder adenomas are rare lesions(0.5%)associated with potential malignant transformation,particularly with gallbladder adenomas that are≥1 cm in size.Early detection and management are crucial for preventing lethal carcinoma de-velopment.These polyps can often be distinguished from the more often nonneo-plastic cholesterol pseudopolyps(5%-10%),which are benign.Ultrasonography is the first-line tool for initial diagnosis and follow-up when indicated.The question is whether cholecystectomy is always necessary for all adenomas.The manage-ment of gallbladder adenomas is determined according to the size of the tumor,the growth rate of the tumor,the patient’s symptoms and whether risk factors for malignancy are present.Adenomas≥1 cm in size,an age>50 years and a familial history of gallbladder carcinoma are indications for immediate laparoscopic chole-cystectomy.Otherwise,ultrasound follow-up is indicated.For adenomas 6-9 mm in size,the absence of≥2 mm growth at 6 months,one year,and two years,as well as an adenoma sized<5 mm without existing risk factors indicates that no further surveillance is required.However,it would be preferable to individualize the management in doubtful cases.Novel interventional modalities for preserving the gallbladder need further evaluation,especially to determine the long-term outcomes.

Surgical Management of a Collision Tumor: The Association of Intracranial Meningioma and Macroadenoma

Background: The simultaneous presence of a pituitary adenoma and a meningioma is a rare and underreported condition. The randomly encountered cases need to be reported to further allow our understanding of this collision tumors that are still not understood nor fully described. Patients and Method: We report a case of coexisting nonfunctioning pituitary adenoma and a left temporal lobe meningioma revealed by a 1-year history of progressive vision loss and occasional headaches in a 56-year-old woman. Her clinical condition worsened in the last 5 months with ptosis, cavernous sinus syndrome, and ophthalmoplegia of the right eye without papilledema. There was an improvement in the visual symptoms after subtotal resection of both lesions through a right frontotemporal craniotomy. Histology confirmed a collision tumor. The patient was referred for adjuvant treatment with gamma knife radiosurgery. He was doing well and back to his usual duties 6 months later. Conclusion: A gross total or subtotal resection with adjuvant therapy is the gold standard for the surgical management of collision tumors for a favorable patient outcome.

Advancing Early Detection of Colorectal Adenomatous Polyps via Genetic Data Analysis: A Hybrid Machine Learning Approach

In this study, a hybrid machine learning (HML)-based approach, incorporating Genetic data analysis (GDA), is proposed to accurately identify the presence of adenomatous colorectal polyps (ACRP) which is a crucial early detector of colorectal cancer (CRC). The present study develops a classification ensemble model based on tuned hyperparameters. Surpassing accuracy percentages of early detection approaches used in previous studies, the current method exhibits exceptional performance in identifying ACRP and diagnosing CRC, overcoming limitations of CRC traditional methods that are based on error-prone manual examination. Particularly, the method demonstrates the following CRP identification accuracy data: 97.7 ± 1.1, precision: 94.3 ± 5, recall: 96.0 ± 3, F1-score: 95.7 ± 4, specificity: 97.3 ± 1.2, average AUC: 0.97.3 ± 0.02, and average p-value: 0.0425 ± 0.07. The findings underscore the potential of this method for early detection of ACRP as well as clinical use in the development of CRC treatment planning strategies. The advantages of this approach are highly expected to contribute to the prevention and reduction of CRC mortality.

From traditional serrated adenoma to tubulovillous adenoma and beyond

It is well established that colorectal cancer develops from a series of precursor epithelial polyps, including tubular adenomas, villous/tubulovillous adenomas (VA/TVA), sessile serrated adenomas (SSA) and traditional serrated adenomas (TSA). Of these, TSAs are least common and account for only 5% of all serrated polyps. TSAs are characterised by the presence of a &ldquo;pinecone-like&rdquo; architecture, granular eosinophilic cytoplasm, luminal serrations, ectopic crypt foci (ECF) and elongated, pencillate nuclei. However, the distinct slit-like luminal serrations, reminiscent of small bowel mucosa, appear to be the most unique and reproducible feature to distinguish TSAs from other polyps. There is a contention that TSAs are not inherently dysplastic and that the majority do not show cytological atypia. Two types of dysplasia are associated with TSA. Serrated dysplasia is less well recognised and less commonly encountered than adenomatous dysplasia. In addition, it is now becoming increasingly evident that TSAs can be admixed with HP, SSA and VA/TVA. At a genetic level, polyps may switch phenotype as they accumulate genetic changes, evolving from a serrated pathway to a more conventional one, which could be the basis for a spectrum theory starting out with a TSA with serration and ECF evolving into a TSA with conventional dysplasia and, eventually, to a well-developed conventional adenoma. Nevertheless, there is an exigency for future studies to provide further illumination and bridge the gaps in our present understanding.

Villous adenoma coexistent with focal well-differentiated adenocarcinoma of female urethral orifice: A case report and review of literature

BACKGROUND Villous adenomas of the urinary tract are uncommon. They are morphologically similar to and difficult to differentiate from their counterpart in the colon. The histogenesis and malignant potential are uncertain.CASE SUMMARY A 63-year-old woman was admitted to our hospital with a mass in the urethral orifice. Gross and microscopic pathological examination was suggestive of urethral villous adenoma with focal well-differentiated adenocarcinoma. The whole urethra and part of the bladder were excised. No further treatment was offered. Carcinoembryonic antigen, cytokeratin 7, cytokeratin 20, epithelial membrane antigen, and p53 protein were positive, and the ratio of Ki-67 was 60%. After follow-up at 11 mo, the patient was cured and had no recurrence.CONCLUSION Immunohistochemistry is important for differential diagnosis of villous adenoma of the urinary system. Complete surgical resection of the urinary tract is curative.

Carcinoma in situ arising in a tubulovillous adenoma of the distal common bile duct: A case report

Tubulovillous adenomas are common in the colon and rectum, but are rare in the common bile duct. Biliary adenomas may produce obstructive jaundice, which can be easily confused with a malignant neoplasm or stone. We report a case of a carcinoma in situ arising in a tubulovillous adenoma of the distal common bile duct causing obstructive jaundice. A 55-year-old male presented with a 10-d history of pruritus and progressive jaundice. Abdominal sonography and computed tomography showed a mass in the distal common bile duct. Endoscopic retrograde cholangiopancreatography showed luminal narrowing of the bile duct due to a polypoid mass. Positron emission tomography demonstrated no abnormal uptake. It was thought that this mass was a malignant tumor, thus a pylorus-preserving panceaticoduodenectomy was performed. The final pathology showed a tubulovillous adenoma with carcinoma in situ of the distal common bile duct. At follow-up 8 mo later, endoscopy showed multiple polyps in the rectum, colon and stomach. The polyps were removed by endoscopic mucosal resection and shown to be tubular adenomas with high grade dysplasia. Biliary adenomas require careful follow-up for early detection of recurrence and malignant transformation.

Pyogenic liver abscess associated with large colonic tubulovillous adenoma

Pyogenic liver abscesses usually occur in association with a variety of diseases. Rarely, liver abscess has been reported as the presenting manifestation of colonic tubulovillous adenoma. We report two cases of pyogenic liver abscess without hepatobiliary disease or other obvious etiologies except that one had a history of diabetes mellitus （DM）. The pathogen in the patient with DM was Klebsiella pneumonia （KP）. In both of the patients, Ueus developed about two to three weeks after the diagnosis of liver abscess. Colonoscopy revealed large polypoid tumors with pathological findings of tubulovillous adenoma in both cases. Two lessons were learned from these two cases： （1） an underlying cause should be aggressively investigated in patients with cryptogenic liver abscess; （2） DM could be one of the etiologies but not necessarily the only cause of KP liver abscess.

Evidence for colorectal sarcomatoid carcinoma arising from tubulovillous adenoma

Sarcomatoid carcinomas of the colorectum are rare tu- mors that display both malignant epithelial and stromal components. Clinically, they are aggressive tumors with early metastasis. Due to their infrequent occurrence, the pathogenesis is poorly understood. We report a case of a 52-year-old woman who presented with a rectal mass and intermittent hematochezia. Superficial biopsies during colonoscopy revealed a tubulovillous adenoma with high-grade dysplasia. Endoscopic ultra- sonography confirmed an invasive nature of the mass, and deeper biopsies revealed the presence of neoplasm with mixed histological components. The surgically- excised specimen demonstrated the presence of poorly differentiated spindle cells underneath the tubulovillous adenoma and an intermediate stage of invasive adeno- carcinoma. Based on the histological appearance and immunohistochemical studies, a diagnosis of sarcoma- toid carcinoma was made. Only nine cases of sarcoma- toid carcinomas of the colorectum have been reported to date. As a result, the terminology and pathogenesis of sarcomatoid carcinoma remain speculative. To the best of our knowledge, this is the first report of co- existence of sarcomatoid carcinoma and invasive ad- enocarcinoma with tubulovillous adenoma; all stages represented within the same tumor. This observation supports the "monoclonal theory" of pathogenesis with an adenoma-sarcoma progression with or without an intermediate stage of carcinoma.