Appendiceal intussusception due to endometriosis presenting as acute right lower quadrant pain.

Appendiceal intussusception is a rare condition characterized by the telescoping or invagination of a portion or the entire appendix into the caecum or within the appendix itself. Diagnosing appendiceal intussusception can be challenging due to its rarity, non-specific symptoms, and lack of awareness among physicians. We present a case report of appendiceal intussusception caused by endometriosis presenting with recurrent abdominal pain in a young female that was initially missed on CT scan and laparoscopy and eventually diagnosed on CT enterography.

Silent but Significant: A Case Report of Appendiceal Mucocele.

Appendiceal mucocele is a rare disease that can sometimes mimic acute appendicitis or be discovered accidentally during surgeries. The clinical presentation of appendiceal mucocele is observed as lumen distension due to mucin accumulation. This condition has both benign and malignant underlying etiologies, which can be confirmed by histopathological examination. Acute presentation of appendiceal mucocele is rare and mostly resembles the symptoms of acute appendicitis. The treatment of appendiceal mucocele is crucial due to the risk of pseudomyxoma peritonei caused by the spread of mucus, mucocele perforation, or the presence of malignancy such as mucinous carcinoma. Surgical resection, either appendicectomy, typhlectomy, or sometimes right hemicolectomy, is the recommended management approach. This is a case of a 74-year-old male with pain in the abdomen as the major presenting complaint. He had a palpable right iliac fossa mass. The diagnosis of appendiceal mucocele was made by contrast-enhanced computed tomography, which was later confirmed by histopathology. The patient underwent surgical resection and was doing well at the three-month follow-up.

Single-cell sequencing of the vermiform appendix during development identifies transcriptional relationships with appendicitis in preschool children.

BACKGROUND: The development of the human vermiform appendix at the cellular level, as well as its function, is not well understood. Appendicitis in preschool children, although uncommon, is associated with a high perforation rate and increased morbidity. METHODS: We performed single-cell RNA sequencing (scRNA-seq) on the human appendix during fetal and pediatric stages as well as preschool-age inflammatory appendices. Transcriptional features of each cell compartment were discussed in the developing appendix. Cellular interactions and differentiation trajectories were also investigated. We compared scRNA-seq profiles from preschool appendicitis to those of matched healthy controls to reveal disease-associated changes. Bulk transcriptomic data, immunohistochemistry, and real-time quantitative PCR were used to validate the findings. RESULTS: Our analysis identified 76 cell types in total and described the cellular atlas of the developing appendix. We discovered the potential role of the BMP signaling pathway in appendiceal epithelium development and identified HOXC8 and PITX2 as the specific regulons of appendix goblet cells. Higher pericyte coverage, endothelial angiogenesis, and goblet mucus scores together with lower epithelial and endothelial tight junction scores were found in the preschool appendix, which possibly contribute to the clinical features of preschool appendicitis. Preschool appendicitis scRNA-seq profiles revealed that the interleukin-17 signaling pathway may participate in the inflammation process. CONCLUSIONS: Our study provides new insights into the development of the appendix and deepens the understanding of appendicitis in preschool children.

The Hidden Diverticula: A Case Report on Appendiceal Diverticulosis.

Diverticulosis of the appendix (DA) is a rare condition, often asymptomatic and incidentally discovered, with a significant association with neoplasia. The prevalence of neoplasia in specimens without DA versus those with DA was 1.28% and 26.94%, respectively. Here, we discuss a case of a 54-year-old male presented with left flank pain and dysuria. Examination showed left renal angle tenderness and leukocytosis. CT scan revealed a left ureteric stone and an enlarged appendix. The urology team placed a double-J catheter, and surgical consultation led to an appendectomy. Histopathology confirmed DA with acute inflammation, serositis, and fibroblast proliferation without malignancy. This case underscores the need to consider DA in differential diagnoses and the importance of thorough histopathological examination and timely surgical intervention.

Appendiceal Elastofibroma Requiring Ileocecectomy.

Elastrofibromas are rare lesions characterized by collagen and elastic fiber deposition. They are generally found in soft tissues and throughout the gastrointestinal tract. The pathogenesis of this lesion is still uncertain, but it is hypothesized to be a reactive process. We present a case of an appendiceal elastofibroma, a unique anatomic location that necessitated surgical removal, with pathologic findings suggestive of an inciting event from a sclerosed vascular abnormality.

Postoperative 68Ga-DOTATATE positron emission tomography has a low yield in incidental appendiceal neuroendocrine tumours.

INTRODUCTION: Rarely, appendiceal neuroendocrine tumours (NET) are an incidental finding when an appendicectomy is undertaken for suspected appendicitis. The role of further imaging in this setting is poorly defined. Positron emission tomography (PET) using 68Ga-DOTATATE is requested to evaluate post-surgical status, however, there is little evidence to guide how it should be employed. The aims of this project are to: (i) characterize 68Ga-DOTATATE PET findings in patients with incidental appendiceal NETs and (ii) discuss how these data might inform post-surgical imaging with PET. METHODS: We reviewed 47 PET scans in 30 patients, undertaken from 2009 to 2018. Scintigraphic findings, histopathological characteristics of the initial appendiceal lesion and medical records were reviewed. RESULTS: Most patients (n = 15) had small (<10 mm) appendiceal NETs with low grade (Ki67 < 2%) features. Eight patients had tumours between 10 and 20 mm, and seven had tumours >20 mm. Goblet cell features were identified in two patients. Three positive PET scans were reported in one patient with an index tumour measuring 40 mm and Ki67 < 2%. The remaining 29 patients had 44 negative scans. Clinical outcome data were available in 27 patients (mean follow-up time 57 months; range 6-123 months). There was no evidence of recurrent neuroendocrine disease at the time of the last follow-up. CONCLUSION: These data indicate that in most cases, post-surgical 68Ga-DOTATATE PET is negative in patients with incidentally detected appendiceal NETs. Clinical outcome data suggest that 68Ga-DOTATATE PET should be reserved for patients with large tumours (>20 mm) or those displaying goblet cell features.

Goblet cell carcinoid of the appendix: Six case reports.

BACKGROUND: Goblet cell carcinoid (GCC) of the appendix is a rare tumor characterized by neuroendocrine and adenocarcinoma features. Accurate preoperative diagnosis is very difficult, with most patients complaining mainly of abdominal pain. Computed tomography shows swelling of the appendix, so diagnosis is usually made incidentally after appendectomy based on a preoperative diagnosis of appendicitis. Even if a patient undergoes preoperative colonoscopy, accurate endoscopic diagnosis is very difficult because GCC shows a submucosal growth pattern with invasion of the appendiceal wall. CASE SUMMARY: Between 2017 and 2022, 6 patients with GCC were treated in our hospital. The presenting complaint for 5 of these 6 patients was abdominal pain. All 5 patients underwent appendectomy, including 4 for a preoperative diagnosis of appendicitis and the other for diagnosis and treatment of an appendiceal tumor. The sixth patient presented with vomiting and underwent ileocecal resection for GCC diagnosed from preoperative biopsy. Although 2 patients with GCC underwent colonoscopy, no neoplastic changes were identified. Two of the six patients showed lymph node metastasis on pathological examination. As of the last follow-up (median: 15 mo), all cases remained alive without recurrence. CONCLUSION: As preoperative diagnosis of GCC is difficult, this possibility must be considered during surgical treatments for presumptive appendicitis.

Appendiceal goblet cell adenocarcinoma with perineural invasion extending into the ileocecal lesion.

BACKGROUND: Appendiceal goblet cell adenocarcinoma (GCA) is a rare subtype of primary appendiceal adenocarcinoma with an incidence of 1-5 per 10,000,000 people per year. Appendiceal tumors are often diagnosed after appendectomy for acute appendicitis. Notably, however, there is currently no standard treatment strategy for GCA, including additional resection. We report a case of appendiceal GCA with perineural extension into the cecum, in which ileal resection was considered effective. CASE PRESENTATION: A 41-year-old man was diagnosed with acute appendicitis and underwent appendectomy. Histopathological findings revealed GCA (T3, Pn1). He was referred to our hospital for additional resection. Preoperative examination indicated a diagnosis of GCA cT3N0M0. Laparoscopic ileocecal resection and D3 lymph node dissection were performed 2 months after initial appendectomy. The patient had a good postoperative course and was discharged 8 days after surgery. Histopathological findings showed a GCA invading the cecum, despite an intact appendiceal stump, no lymph node metastasis, no vascular invasion, and no horizontal extension into the submucosa. Direct invasion of the tumor through the serosa was not observed, but perineural extension was conspicuous in the cecum, suggesting that the GCA extended into the cecum via perineural invasion. The resection margins were negative. The patient has survived free of recurrence for a year after ileocecal resection. CONCLUSIONS: The current patient was diagnosed with appendiceal GCA following appendectomy for acute appendicitis. Despite intact of appendiceal stump and no evidence of lymph node or distant metastasis, he underwent laparoscopic ileocecal resection and D3 lymph node dissection 2 months after initial appendectomy, with a favorable outcome. Despite the detection of perineural invasion, the patient declined adjuvant therapy. This case suggests that extensive resection may be required in patients with appendiceal GCA, but the role of adjuvant therapy remains unclear.

Low-grade appendiceal mucinous neoplasm penetrating sigmoid colon: A case report.

Low-grade appendiceal mucinous neoplasm (LAMN) is principally characterized by low-grade cytology without evidence of invasion to other organs. We report a LAMN surgical case whose appendiceal tumor penetrated the sigmoid colon wall. An 87-year-old man was referred for endoscopic resection (ER) of a colon polyp. Despite four ERs over 5 years, the polyp recurred at the same site. Laparoscopic surgery revealed a dilated appendix firmly attached to the sigmoid colon. We performed en bloc resection of both the sigmoid colon and appendix without tumor exposure. The histopathological evaluation showed that the LAMN had penetrated the sigmoid colon wall, forming two polyps on the colonic mucosa. In cases where the appendiceal-colonic fistula is suspected, en bloc resection of the appendix and colon wall should be considered.

New insights in the management of pseudomyxoma peritonei.

While a rare entity, peritoneal pseudomyxoma treatment evolves. Decision-making criteria improve with imaging development and exploratory laparoscopy. Surgery remains at the core of the therapeutic strategy whatever disease progression. Complete cytoreduction plus hyperthermic intraperitoneal chemotherapy (HIPEC) is standard of care. Iterative cytoreduction or debulking is sometimes justified. Intraperitoneal chemotherapy modalities change with early postoperative HIPEC or pressurized intraperitoneal aerosol chemotherapy. Systemic or local treatment such as new chemo/immuno-therapies or BromAc should improve outcomes. Expertise and multicentric cooperation are more than ever needed.

Well-differentiated neuroendocrine tumors of the appendix: Diagnosis, differentials, and disease progression.

Well-differentiated neuroendocrine tumors are the most common neoplasm of the appendix. They are graded and staged using World Health Organization and American Joint Committee on Cancer criteria, respectively. They may be invisible grossly or form rounded yellow nodules, sometimes in the appendiceal tip. They show classic neuroendocrine tumor features microscopically, forming nests and cords of monotonous cells with salt-and-pepper chromatin and amphophilic cytoplasm. They are positive for neuroendocrine markers by immunohistochemistry, but their molecular characteristics are not well defined. pT-category staging relies primarily on tumor size, though higher-stage cases may involve the subserosa or mesoappendix. Few entities enter the differential diagnosis, but lesions such as goblet cell adenocarcinoma, poorly differentiated neuroendocrine carcinoma, and mixed neuroendocrine-non-neuroendocrine neoplasm may be considered. Appendiceal neuroendocrine tumors may metastasize to regional lymph nodes, but farther spread is rare. The most consistently proven risk factor for such spread is tumor size, though different studies have proposed different cutoffs. Other potential risk factors include lymphovascular invasion and margin positivity. Tumors smaller than 1 cm can be treated by appendectomy, while hemicolectomy is recommended for tumors larger than 2 cm. Proper treatment for cases measuring 1-2 cm remains a matter of debate.

Exploring the mysterious mucinous appendiceal neoplasm.

Mucinous neoplasms of the appendix comprise a group of diagnostically challenging lesions that have generated significant controversy and confusion throughout the years, given their potential for aggressive behavior despite very bland cytologic features. Numerous classification schemes have been proposed to characterize and stage these lesions, but confusion remains among pathologists, surgeons, and oncologists regarding diagnostic criteria, therapeutic implications, and overall prognosis. This review summaries the current recommended nomenclature, histologic characteristics of each entity, and helpful features to distinguish neoplasia from benign mimics.

Appendiceal adenocarcinoma: Current concepts & challenges.

Appendiceal adenocarcinoma (ApAC) is a rare malignancy, comprising less than 1 % of all gastrointestinal tumors. The current World Health Organization classifies ApAC as mucinous or nonmucinous. Mucinous ApAC are composed of pools of mucin lined by cells with low- and high-grade cytology and areas of infiltrative invasion. Nonmucinous ApAC histologically resemble conventional colorectal adenocarcinomas and have a worse prognosis than their mucinous counterpart. Unfortunately, the nomenclature and histologic classification of ApAC, specifically the mucinous subtype, has changed several times throughout the years, contributing to diagnostic confusion for pathologists. The treatment for mucinous ApAC differs from that of other appendiceal mucinous neoplasms, thus accurate diagnosis is key to patient management and outcome. This review discusses the current classification and staging of ApAC with a particular emphasis on the mucinous subtype and peritoneal disease, as these areas are the most challenging for practicing surgical pathologists.

De Garengeot hernia: A unique presentation of femoral hernia with perforated appendicitis.

INTRODUCTION: De Garengeot hernia is a rare subset of femoral hernias containing the vermiform appendix. It is more common in females. The presenting symptoms are non-specific hence diagnosis is challenging and there is no consensus on treatment of it. PRESENTATION OF CASE: An 85-year-old male patient who had previously undergone herniorrhaphy presented with a four-day history of pain and swelling in the right groin region. On a contrast-enhanced computed tomography scan it revealed incarceration of the appendix within femoral hernia. It was managed with appendectomy and closure of the defect using non-absorbable suture. DISCUSSION: Diagnosis of De Garengeot hernias remains challenging due to their non-specific presentation and attenuated clinical symptoms, often leading to intraoperative identification. It is crucial for physicians to recognize this rare presentation of appendicitis and be familiar with the available surgical interventions. However, the literature does not establish a consensus regarding the preferred surgical approach. CONCLUSION: De Garengeot hernia remains an uncommon and challenging presentation of femoral hernia, particularly when complicated by appendiceal incarceration leading to acute appendicitis. Surgical management should be tailored to each patient's unique circumstances.

TRPC6 is ubiquitously present in lymphatic tissues: A study using samples from body donors.

Transient receptor potential canonical channel 6 (TRPC6) is a non-selective cation channel that is activated by diacylglycerol. It belongs to the TRP superfamily, is expressed in numerous tissues and has been shown to be associated with diseases, such as focal segmental glomerulosclerosis, idiopathic pulmonary arterial hypertension and cardiac hypertrophy. The investigation of the channel in human lymphoid tissues has thus far been limited to mRNA analysis or the western blotting of isolated lymphoid cell lines. The present study aimed to detect the channel in human lymphoid tissue using immunohistochemistry. For this purpose, lymphatic tissues were obtained from body donors. The lymphatic organs analyzed included the lymph nodes, spleen, palatine tonsil, gut-associated lymphoid tissues (ileum and vermiform appendix) and thymus. A total of 102 samples were obtained and processed for hematoxylin and eosin (H&E) staining. The H&E staining method was employed to identify five samples with good morphology. In total, three samples of the palatine tonsil of patients were included. Immunostaining was carried out using a knockout-validated anti-TRPC6 antibody. As shown by the results, using immunohistochemical staining, the presence of TRPC6 was confirmed in all the analyzed lymphatic tissue samples. Lymphocytes in lymph nodes, spleen, palatine tonsil, thymus, and gut-associated lymphatic tissues in ileum and vermiform appendix exhibited a positive staining signal. The follicle-associated epithelium of the palatine tonsil, ileum and appendix also demonstrated staining. Vessels of the lymphatic organs, particularly the trabecular arteries of the spleen, the submucosal vessels of the appendix and ileum, as well as the high endothelial venules in the palatine tonsils and lymphatic vessels of the lymph nodes expressed TRPC6 protein. TRPC6 in follicles may be involved in the immune response. TRPC6 in high endothelial venules suggests a role in leukocyte migration. The role of TRPC6 and other channels of the TRP family in lymphatic organs warrant further investigations to elucidate whether TRP channels are a pharmacological target.

Incidental detection of an appendiceal neuroendocrine tumor in a right hemicolectomy specimen for colonic adenocarcinoma: A case report.

INTRODUCTION AND IMPORTANCE: Incidental detection of neuroendocrine tumors (NETs) of the appendix is rare, often discovered during surgeries for other conditions. This report emphasizes the importance of thorough pathological evaluations in colorectal surgeries. CASE PRESENTATION: A 48-year-old male presented with intermittent abdominal pain, weight loss, and altered bowel habits. Colonoscopy and biopsy confirmed adenocarcinoma of the right colon. The patient underwent a right hemicolectomy. Histopathological examination revealed a moderately differentiated adenocarcinoma of the ascending colon (pT3N2b) and an incidental 0.8 cm well-differentiated NET at the tip of the appendix. The NET was low-grade (G1) with no lymphovascular invasion or metastasis. The patient received adjuvant chemotherapy with oxaliplatin and capecitabine for the colonic adenocarcinoma. The incidental NET did not alter the chemotherapy regimen due to its low-risk features. DISCUSSION: Although, the presence of the NET did not alter the chemotherapy regimen, given its small size and low-grade nature. However, the discovery of this incidental tumor highlights the need for diligent follow-up, as patients with synchronous tumors may have an increased risk of recurrence or development of new malignancies. CONCLUSION: This case highlights the significance of meticulous pathological examination in colorectal surgeries, as incidental findings can significantly impact patient management and follow-up. Despite the typically indolent nature of small appendiceal NETs, their detection is crucial for accurate staging and appropriate patient care.

Pseudomyxoma Peritonei: An Incidental Diagnosis With Atypical Intraoperative Findings Discovered During a Laparoscopic Cholecystectomy.

Although pseudomyxoma peritonei (PMP) classically presents with profuse mucinous ascites within the peritoneal cavity, the physical manifestations of this disease exist on a spectrum, with the possibility of milder forms that lack typical findings. The authors report an indolent case of PMP diagnosed incidentally during workup and treatment for chronic cholecystitis in a 43-year-old male. This presentation of PMP was atypical due to a lack of discernible symptoms as well as uncharacteristic intraoperative findings consisting of numerous omental and pelvic adhesions with only sparse mucinous deposits. This case contributes to the growing understanding of PMP by exploring an uncharacteristic presentation of the disease with the hope that it may assist clinicians in diagnosing those cases of PMP that are more indolent and insidious in nature.

Histopathological Diagnosis of a Case of Mucin-Secreting Adenocarcinoma of the Appendix.

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.

Through Different Lenses: A Retrospective Analysis of the Agreement Between Laparoscopic and Histopathological Evaluations of the Appendix.

BACKGROUND: Appendicectomy is the most frequently performed emergency general surgical procedure. Previous research has highlighted discrepancies between initial intraoperative laparoscopic diagnoses and subsequent histopathology reports following appendicectomy. In the United Kingdom (UK), routine histopathological examination is the established practice, ensuring precise diagnosis of appendiceal specimens. This retrospective analysis aims to compare intraoperative laparoscopic assessments of the appendix with corresponding histopathology findings. METHODOLOGY: We conducted a retrospective analysis of 418 consecutive emergency laparoscopic appendectomies at Peterborough City Hospital in the UK between April 2018 and June 2019 for suspected appendicitis. Intraoperative findings were compared with histopathological examination outcomes using kappa statistics. RESULTS: Of the 418 appendectomies analysed, we found a substantial agreement between surgeons and pathologists (kappa = 0.71, P < 0.001) in detecting overall abnormalities of appendices. This agreement was also high for detecting inflamed appendices (kappa = 0.72, P < 0.001). However, of the six neoplastic lesions confirmed in the pathologists' final report, only two were suspected during laparoscopy. CONCLUSIONS: While laparoscopic assessments of the appendix demonstrate a statistically significant and improved agreement with histopathological findings in detecting abnormal and inflamed appendices, the ability of surgeons to identify neoplasia appears suboptimal based on our small sample of neoplasia cases. The data strongly support the continued practice of routine histopathological examination following appendicectomy due to its crucial role in avoiding missed diagnoses and ensuring better patient outcomes.