Asymptomatic low-grade appendiceal mucinous neoplasm:A case report

BACKGROUND Low-grade appendiceal neoplasms(LAMN)are characterized by low incidence and atypical clinical presentations,often leading to misdiagnosis as acute or chronic appendicitis before surgery.The primary diagnostic tool for LAMN is abdominal computed tomography(CT)imaging.Surgical resection remains the cornerstone of LAMN management,necessitating en bloc tumor excision to minimize the risk of iatrogenic rupture.Laparoscopy,known for its minimal invasiveness,reduced postoperative discomfort,and expedited recovery,is a safe and reliable approach for LAMN treatment.Despite the possibility of pseudomyxoma peritonei development,appendectomy and partial appendectomy generally result in negative tumor margins and favorable outcomes,which can be attributed to the disease’s slow growth and lower malignancy.CASE SUMMARY A 71-year-old male patient was admitted to our hospital with a pelvic spaceoccupying lesion detected 1 mo prior.Physical examination showed a soft abdomen without tenderness or rebound and no palpable masses.No shifting dullness was noted,and digital rectal examination revealed no palpable mass.Enteroscopy revealed a raised,smooth-surfaced mass measuring 3.0 cm in the cecum.Abdominal contrast-enhanced CT showed a markedly thickened and dilated appendix with visible cystic shadows.Laparoscopic surgery was performed and revealed a significantly dilated appendix,leading to laparoscopic resection of the appendix and part of the cecum.Post-surgical pathologic analysis confirmed LAMN.The patient received symptomatic and supportive post-operative care and was discharged on postoperative day 4 without complications such as abdominal bleeding,intestinal obstruction,or incision infection.No tumor recurrence was observed during a 7-mo follow-up period.CONCLUSION LAMN is a rare disease that lacks specific clinical manifestations.Abdominal CT plays a crucial role in diagnosing LAMN,and laparoscopic surgery is a safe and effective diagnostic and therapeutic approach.

Advances in the Diagnosis and Treatment of Appendiceal Mucinous Neoplasms

Primary appendiceal neoplasms represent a relatively low percentage of all gastrointestinal cancers. A subset of these neoplasms, those of epithelial origin, are characterised by the production of a considerable amount of mucus, which is referred to as appendiceal mucinous neoplasms (AMN). Appendiceal mucinous neoplasms (AMN) have a low incidence, are easily misdiagnosed, depend on postoperative examination for confirmation of the diagnosis, are prone to form a “diagnosis”, and have a high incidence of the disease. Furthermore, they are prone to form peritoneal pseudomyxoma peritonei (PMP), are controversial in surgical decision-making, are prone to recurring after surgery alone, and are tricky to manage clinically. In this paper, we review the pathological characteristics, diagnosis and treatment of appendiceal mucinous tumours in the light of recent literature reports, with a view to providing certain references for the clinical diagnosis and treatment of this disease. .

Treatment of a giant low-grade appendiceal mucinous neoplasm:A case report

BACKGROUND Low-grade appendiceal mucinous neoplasm(LAMN)is extremely rare and easily misdiagnosed before surgery.CASE SUMMARY We report the treatment of an asymptomatic case of LAMN diagnosed by magnetic resonance imaging(MRI)and surgical findings.A 70-year-old woman presented with an adnexal mass found by physical examination in July 2020.Gynecologic ultrasonography revealed a cystic mass in the right adnexa,and computed tomography showed a cystic mass in the pelvic cavity.All tumor markers were normal.A further MRI examination suggested mucinous neoplasm in the right pelvic cavity,excluding the possibility of adnexal cyst.Laparoscopic exploration found a huge cystic mass of about 10 cm×7 cm that originated from the apex of the appendix,with spontaneous rupture.LAMN was confirmed by pathological examination.As of May 2021,no disease recurrence occurred after an open appendectomy.CONCLUSION This case indicates that we should pay more attention to female patients who are clinically diagnosed with an adnexal mass at admission,.The physical examination should be done carefully,and the laboratory and imaging examination results should be comprehensively analyzed to avoid misdiagnosis and to ensure prompt diagnosis and treatment,and to improve prognosis.MRI may be a better option for the diagnosis of appendiceal mucinous neoplasm.

Evaluation of appendiceal mucinous neoplasms by curved lineararray echoendoscope:A preliminary study

BACKGROUND Preoperative diagnosis of appendiceal mucinous neoplasms is challenging,and there are few reports regarding the endosonographic characteristics of these neoplasms.AIM To provide a retrospective assessment of the imaging features of appendiceal mucinous neoplasms using endoscopic ultrasound(EUS)by curved linear-array echoendoscope.METHODS A database of all patients with appendiceal mucinous neoplasms who had received EUS examination at our hospital between January 2018 and July 2023 was retrospectively analyzed.The EUS characteristics and patients’clinical data were reviewed.RESULTS Twenty-two patients were included in the study.The linear-array echoendoscope successfully reached the ileocecal region in every patient.In the endoscopic view,we could observe the protrusion in the appendiceal orifice in all patients.A volcano sign was observed in two patients,and an atypical volcano sign was seen in two patients.EUS showed that all 22 lesions were submucosal cystic hypoechoic lesions with clear boundaries.No wall nodules were observed,but an onion-peeling sign was observed in 17 cases.CONCLUSION Linear-array echoendoscope is safe to reach the ileocecal region under the guidance of EUS.Image features on endoscopic and echoendosonograhic views could be used to diagnose appendiceal mucinous neoplasms.

Synchronous Mucinous Borderline Tumor of the Ovary and Low-Grade Appendiceal Mucinous Neoplasm

We present a rare case of synchronous mucinous borderline tumor of the ovary and low-grade appendiceal mucinous neoplasm (LAMN). We performed a left adnexectomy to diagnose the left ovarian borderline malignancy and an ileostomy because of the swollen appendix during the operation. It was diagnosed as left ovarian mucinous borderline malignancy and LAMN. LAMN causes peritoneal dissemination, ovarian metastasis, and peritoneal pseudomyxoma. The appendix and ovary are close to each other anatomically and can metastasize if there is a tumor in either. For ovarian mucinous tumors, it is necessary to search the gastrointestinal tract, especially the appendix, as the primary lesion. For appendix tumors, it is necessary to search for the ovary. Since LAMN may be associated with borderline ovarian malignancies, as in this case, there is a possibility of the duplication of tumors when searching for ovarian mucinous tumors as the primary tumor and if ovarian tumors are found. Since LAMN and mucinous ovarian tumors have similar histological features, immunohistochemical staining is useful for their differentiation because they show different immunostaining patterns.

A Case of Low-Grade Appendiceal Mucinous Neoplasm of Its Difficultly to Distinguish from a Right Ovarian Tumor Due to Postmenopause

We here present a rare case of appendiceal tumor mimicking ovarian tumor in menopause woman. The patient was a 56-year-old woman, G1P1, who presented to our hospital with a right adnexal cyst diagnosed at another hospital. Transvaginal echocardiography showed a cyst in the right adnexal region, and pelvic contrast-enhanced MRI revealed a small cyst in the same region. The left ovary was atrophic and identifiable. It was unclear whether the cyst was contiguous with the gastrointestinal tract. Blood tests showed no elevation of tumor markers. We considered its possibility of a gastrointestinal origin, but since right normal ovary was not found, we thought the tumor was of ovarian origin and decided on a laparoscopic resection of the right adnexa. Intraoperatively, we observed atrophied bilateral normal ovaries, and the pelvic tumor was contiguous to the appendix. Surgeons performed a laparoscopic appendectomy after consultation with us. After resection we searched the abdominal and pelvic cavities, but found no obvious disseminated lesions. The histological diagnosis was low-grade appendiceal mucinous neoplasm (LAMN), a rare benign tumor of the appendix. Appendiceal tumors can be difficult to differentiate from right ovarian tumors due to their close anatomic location in the pelvis. It is possible to determine whether the tumor is of ovarian or appendiceal origin by identifying normal ovaries and the location of the feeding vessels into the tumors. In our case, there were no lesions other than the appendix, but LAMN can metastasize to the ovary, cause pseudomyoxoma peritonei, or be an overlapping tumor with an ovarian tumor. If an appendiceal tumor is diagnosed after surgery for ovarian tumor, the intra-abdominal cavity should be searched for metastasis or dissemination, and a thorough search for ovarian lesions should be performed with the possibility of an overlapping tumor in mind.

Low Grade Appendiceal Mucinous Neoplasm Presenting as a Mucocoele of the Appendix

Low grade appendiceal mucinous neoplasm (LAMN) is a rare malignancy with incidence of 0.7% to 1.7% of all appendicectomies [1]. LAMN has the worst complication of mucin seeding into adjacent peritoneum leading to pseudomyxoma peritonei. LAMN lacks standardised treatment approach where only appendicectomy is preferred for resection of non metastatic disease. Case Presentation A 38 yr old female presented with right lower quadrant where CT Abdomen revealed Mucocele of Appendix. Patient underwent Laparoscopic Appendicectomy and Histopathological examination revealed Low grade appendiceal mucinous neoplasm. Patient is on regular follow up and is disease free. Conclusion low grade appendiceal mucinous neoplasm is usually an incidental finding where treatment depends on staging and histology of the tumour.

Mucinous neoplasm of the appendix:A case report and review of literature

BACKGROUND Appendiceal mucinous neoplasms(AMNs),although not classified as rare,are relatively uncommon tumors most often discovered incidentally during colorectal surgery.Accurate identification of AMNs is difficult due to non-specific sym-ptoms,overlapping tumor markers with other conditions,and the potential for misdiagnosis.This underscores the urgent need for precision in diagnosis to pre-vent severe complications.CASE SUMMARY This case report describes the unexpected discovery and treatment of a low-grade AMN(LAMN)in a 74-year-old man undergoing laparoscopic hemicolectomy for transverse colon adenocarcinoma(AC).Preoperatively,non-specific gastroin-testinal symptoms and elevated tumor markers masked the presence of AMN.The tumor,presumed to be an AMN peritoneal cyst intraoperatively,was con-firmed as LAMN through histopathological examination.The neoplasm exhibited mucin accumulation and a distinct immunohistochemical profile:Positive for Ho-meobox protein CDX-2,Cytokeratin 20,special AT-rich sequence-binding protein 2,and Mucin 2 but negative for cytokeratin 7 and Paired box gene 8.This profile aids in distinguishing appendiceal and ovarian mucinous tumors.Postoperative recovery was uncomplicated,and the patient initiated adjuvant chemotherapy for the colon AC.CONCLUSION This case highlights the diagnostic complexity of AMNs,emphasizing the need for vigilant identification to avert potential complications,such as pseudomyxoma peritonei.

Beyond boundaries:Feasibility of curved linear array echoendoscope in appendiceal neoplasm detection

We recently read with great interest a study by Zhang et al in the World Journal of Gastroenterology.In our practice,we focus specifically on examining appendiceal mucinous neoplasms(AMNs)with endoscopic ultrasound(EUS)using different scopes.AMNs are rare neoplastic lesions characterized by an accumulation of mucin inside a cystic dilatation of the appendix.Clinically,they can present as nonspecific acute appendicitis.AMNs can turn into a life-threatening condition,termed pseudomyxoma peritonei,in which the ruptured appendix causes accumulation of mucin in the abdomen.Therefore,accurate and rapid diagnosis of AMN is essential.EUS is able to confirm and stage AMNs;although,EUS examination was once limited to the rectal and anal regions due to the conven-tional oblique-view scopes.With the emergence of new forward-view linear echoendoscopes and instruments like EUS miniprobes and overtubes,the scope of examination is changing.Herein,we discuss the feasibility of using the curved linear array echoendoscopes to examine cecal and appendiceal orifice lesions.

Mucinous appendiceal neoplasm:A case report

BACKGROUND Primary appendiceal tumors are histologically diverse and have an insidious onset and few specific clinical manifestations.In the majority of cases,these tumors are discovered after appendectomy during pathological exam of the resected tissue.Treatment may include appendectomy(simple or radical)and right hemicolectomy depending on factors such as histological type,tumor size and lymph node/organ involvement.The aim of this case study is to describe a rare case of a giant appendicular mucocele and raise awareness of this condition and its management options and follow-up protocol.CASE SUMMARY We present the case of a 43-year-old patient who presented to our emergency department with mild right lower quadrant pain.After the initial check-up and imaging exams,he underwent surgery,where a giant 20 cm×13 cm appendicular tumor was found and resected.Appendicular mucocele was suspected due to the macroscopic appearance and was later confirmed by the pathological exam.The patient’s postoperative evolution was uneventful,and after discharge,he was included in our follow-up program.CONCLUSION In conclusion,mucinous appendiceal neoplasms embody a rare pathology;they are asymptomatic or have few,unspecific clinical signs and in many cases are discovered after appendectomy.