Mucin-secreting adenocarcinoma of the appendix is a very rare, slow-growing, mucin-producing epithelial neoplasm of the appendix. It is usually found accidentally in an appendicectomy specimen with the presentation of acute appendicitis in most patients or when there is a rupture of the primary tumor with the mucin spreading along with the tumor cells in the entire peritoneal cavity. Here we describe a case of low-grade (well-differentiated) mucin-secreting adenocarcinoma in the appendix. A 48-year-old female presented with complaints of abdominal distension with no other complaints of fever, pain, or breathlessness. Carcinoembryonic antigen levels were 44.8 ng/mL. Cytoreduction surgery of bilateral ovaries was done. The final histopathological diagnosis was reported as low-grade (well-differentiated) mucin-secreting adenocarcinoma of the appendix staged at pT4b pNx pM1c. Pseudomyxoma peritonei is a very feared complication and also, at times, the only presenting symptom where there is an accumulation of mucin in the intra-abdominal cavity due to the spread of mucin-secreting cells, which in turn causes an increase in the abdominal girth along with discomfort for the patient. The mainstay of treatment remains cytoreductive surgery along with hyperthermic intraperitoneal chemotherapy.

High-grade appendiceal mucinous neoplasm (HAMN) has been separated from appendiceal adenocarcinoma recently as an independent entity and categorized into appendiceal mucinous neoplasms. These neoplasms demonstrate distinct histological characteristics, including architectures and appendiceal mural changes similar to low-grade appendiceal mucinous neoplasm but with high-grade cytology, and no infiltrative invasion. Overt mucinous feature are not evident in some cases as the high-grade neoplastic epithelium may show intracytoplasmic mucin reduction. Occasionally, the neoplastic epithelial cells show florid proliferation and tubulovillous configuration and may be misdiagnosed as appendiceal tubulovillous adenoma. We report the case of a 67-year-old woman with appendicular dilatation and luminal mucin. She underwent an ileocecoectomy. The appendiceal lesion was found histologically to be a HAMN, which closely resembled appendiceal tubulovillous adenoma. The tumor cells demonstrated wild-type p53 expression and mismatch repair proficiency by immunochemistry. Molecular testing showed 1 KRAS mutation, 2 PIK3CA mutations, and 1 BRCA2, EP300, TGFBR2, CHD4, CREBBP, FANCC, PKHD1 mutation each in the tumor. The patient was followed up for 1 year with no evidence of disease.

Appendiceal mucinous neoplasms are rare and can be easily misdiagnosed as adnexal masses. Fertility is a concern in cases requiring cytoreductive surgery involving the ovaries and if hyperthermic intraperitoneal chemotherapy is considered. We present the case of a 35-year-old patient with primary infertility who was suspected to have a hematosalpinx on ultrasonography and magnetic resonance imaging (MRI) but was found to have an appendiceal mucinous neoplasm on laparoscopy. Fertility preservation was offered to this patient. Appendiceal mucinous neoplasms should be considered in the differential diagnosis of patients in their reproductive years presenting with adnexal masses. Fertility preservation should be discussed with these patients, especially when gonadotoxic treatments are planned.

The 5th edition of the World Health Organization (WHO) classification of tumors of the digestive system distinguishes four categories of appendiceal tumors (ATs): serrated lesions and polyps, mucinous neoplasms, adenocarcinomas, and neuroendocrine neoplasms (NENs). The differential diagnosis of ATs can be challenging in medical practice, due to their rarity and lack of data from randomized controlled trials on a large, diverse group of patients. ATs are usually noted in specimens obtained during appendectomies due to clinical acute appendicitis. In the European population, most ATs (65%) occur over the age of 50 and among women (56.8%). According to histological type, 54.6% are neuroendocrine tumors (NETs); 26.8% cystic, mucinous, and serous neoplasms; and 18.6% adenocarcinoma not otherwise specified (NOS). On pathologic analysis, most AT findings are benign lesions or small NENs that do not require further therapeutic measures. The presence of appendiceal mucinous neoplasm (AMN) can lead to pseudomyxoma peritonei (PMP). While the multimodal treatment for abdominal malignancies has evolved over the past several decades, the clinical workup and treatment of ATs remain a challenge. Therefore, this review aims to describe the diagnostic possibilities, molecular-based diagnosis, staging, differences in the treatment process, and prognostic factors associated with ATs.

Low grade appendiceal mucinous neoplasm (LAMN) is a rare tumor presenting typically with symptoms of acute appendicitis. A 33-year-old gentleman presented with abdominal fullness and discomfort secondary to abdominal trauma obtained during boxing training. Investigations with magnetic resonance imaging (MRI), ultrasound, and colonoscopy revealed a large cystic lesion in the ascending colon mesentery with unclear continuation with the appendix. There were no obvious features of malignancy. Laparoscopy revealed a large, firm mass connected to the appendix with enlarged lymph nodes, and the patient underwent radical resection with a right hemicolectomy. Histopathology revealed complete excision of LAMN with no lymphatic involvement. Post traumatic intra-abdominal cystic lesions pose a diagnostic challenge, and neoplastic lesions cannot be ruled out with imaging alone, even with benign appearances. Careful surgical excision and histopathological diagnosis is the only definitive method of ruling-out malignancy.

UNASSIGNED: Low back pain is the leading cause of disability worldwide. It is also the main cause of the limitation of activities and absence from work in much of the world and a cause of great economic burden. The greatest percentage of low back pain is classified as nonspecific (i.e. not attributable to a defined pathology), while the others may concern specific pathologies of the lumbar region or suggest pathologies of non-musculoskeletal origin. Consequently, evaluating any signs and symptoms mimicking musculoskeletal conditions is crucial.
UNASSIGNED: This case report describes a 64-year-old female patient who first presented to the physiotherapist with two weeks of low back pain, complaining of a different clinical presentation than the previous episodes. The patient\'s pain started spontaneously and was located in the lumbar region over a diffuse area. Symptoms were constant throughout the day and did not change with movement. Based on the examination findings, the physiotherapist decided to make an urgent referral to the patient\'s General Practitioner.
UNASSIGNED: Following ultrasound examination and Computed Tomography scan, an 8.5 cm mass was confirmed in the abdominal region. It was surgically removed, and a histological diagnosis of Low-grade Appendiceal Mucinous Neoplasm (LAMN) was made.
UNASSIGNED: The physiotherapist\'s evaluation and decision-making process was fundamental in the patient\'s referral due to suspected pathology not within the scope of practice. This revealed a rare condition, which, according to the existing literature, is usually diagnosed in the event of collateral imaging findings or upon presentation of complex and/or emergency clinical pictures.

There is no clear evidence on the prevalence and clinical presentation of appendiceal mucinous neoplasm (AMN) among patients with inflammatory bowel disease (IBD), so a systematic review was performed to investigate the diagnosis, management and treatment of AMN in these patients. PubMed, Medline, Scopus and the Cochrane Library were searched for articles published up to September 2023. Twenty-three studies reporting data about 34 AMN patients were included. UC patients had a median age of 52 years and a median length of disease of 10 years; CD patients had a median age of 40.5 years and a median length of disease of 5 years. A pre-operative diagnosis was achieved in 44% of patients. Most patients were symptomatic (82.6%) and showed moderate-severe disease activity (61%). Surgical procedures were performed: laparoscopic appendectomy, ileocecal resection, right hemicolectomy and colectomy/proctocolectomy. Of the patients, 73.5% were diagnosed with low-grade mucinous neoplasm (LAMN) and nine with adenocarcinoma. Synchronous colorectal dysplasia/carcinoma was present in 23.5% of patients. IBD patients with long-standing disease should be routinely screened, not only for colorectal cancer but also for AMN, during gastro-enterologic follow-up. Laparoscopic appendectomy of unruptured LAMN as well as right hemicolectomy of non-metastatic adenocarcinoma are safe procedures in IBD patients.

BACKGROUND: Preoperative diagnosis of appendiceal mucinous neoplasms is challenging, and there are few reports regarding the endosonographic characteristics of these neoplasms.
OBJECTIVE: 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.
CONCLUSIONS: 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.

UNASSIGNED: Mucinous neoplasms are tumors arising in the epithelial tissue, characterized by excessive mucin secretion. They mainly emerge in the digestive system and rarely in the urinary system. They also seldom develop in the renal pelvis and the appendix asynchronously or simultaneously. The concurrence of this disease in these two regions has not yet been reported. In this case report, we discuss the diagnosis and treatment of synchronous mucinous neoplasms of the right renal pelvis and the appendix. The mucinous neoplasm of the renal pelvis was preoperatively misdiagnosed as pyonephrosis caused by renal stones, and the patient underwent laparoscopic nephrectomy. Herein, we summarize our experience with this rare case in combination with related literature.
UNASSIGNED: In this case, A 64-year-old female was admitted to our hospital with persistent pain in the right lower back for over a year. Computer tomography urography (CTU) showed that the patient was confirmed as right kidney stone with large hydronephrosis or pyonephrosis, and appendiceal mucinous neoplasm (AMN). Subsequently, the patient was transferred to the gastrointestinal surgery department. Simultaneously, electronic colonoscopy with biopsy suggested AMN. Open appendectomy plus abdominal exploration was performed after obtaining informed consent. Postoperative pathology indicated low-grade AMN (LAMN) and the incisal margin of the appendix was negative. The patient was re-admitted to the urology department, and underwent laparoscopic right nephrectomy because she was misdiagnosed with calculi and pyonephrosis of the right kidney according to the indistinctive clinical symptoms, standard examination of the gelatinous material, and imaging findings. Postoperative pathology suggested a high-grade mucinous neoplasm of the renal pelvis and mucin residing partly in the interstitium of the cyst walls. Good follow-up results were obtained for 14 months.
UNASSIGNED: Synchronous mucinous neoplasms of the renal pelvis and the appendix are indeed uncommon and have not yet been reported. Primary renal mucinous adenocarcinoma is very rare, metastasis from other organs should be first considered, especially in patients with long-term chronic inflammation, hydronephrosis, pyonephrosis, and renal stones, otherwise, misdiagnosis and treatment delay may occur. Hence, for patients with rare diseases, strict adherence to treatment principles and close follow-up are necessary to achieve favorable outcomes.

Intussusception is a rare presentation in adults and describes when one portion of the intestine telescopes into another portion. Intussusception is associated with malignancies serving as the lead point in adults. Appendiceal mucinous neoplasms are uncommon tumors often incidentally discovered during appendectomy procedures to manage acute appendicitis. Here we present a case report of an instance of mucinous adenocarcinoma of the appendix that manifested as a large bowel obstruction with intussusception limited to the colon, underscoring the possibility of concurrent intussusception and mucinous neoplasms. The case highlights the importance of meticulous diagnostic evaluation and management, particularly without well-defined treatment protocols. Appropriate diagnostic workup and management, including surgical intervention, are critical for patient outcomes and overall prognosis. The study recommends that patients diagnosed with confirmed or suspected appendiceal neoplasms undergo upfront oncologic resection where aggressive malignancy is a concern. Colonoscopy should be performed postoperatively for all patients to identify synchronous lesions.