Appendiceal neuroendocrine neoplasms: diagnosis and management

Gastrointestinal neuroendocrine neoplasms (GI-NENs) are increasingly being recognised, while appendiceal NENs (aNENs) currently constitute the third most common GI-NEN. Appendiceal NENs are generally considered to follow an indolent course with the majority being localised at diagnosis. Thus, the initial surgical approach is not that of a planned oncological resection. Due to the localised nature of the disease in the majority of cases, subsequent biochemical and radiological assessment are not routinely recommended. Histopathological criteria (size, mesoappendiceal invasion, Ki-67 proliferation index, neuro- and angio-invasion) are mainly used to identify those patients who are also candidates for a right hemicolectomy. Goblet cell carcinoids are a distinct entity and should be treated as adenocarcinomas. Despite the absence of any substantial prospective data regarding optimal management and follow-up, recent consensus statements and guidelines have been published. The purpose of this review is to overview the published studies on the diagnosis and management of appendiceal NENs and to suggest a possible management protocol.

Adenocarcinoma of the Appendix Presenting as a Palpable Right Thigh Mass

Intra-abdominal and intra-pelvic pathologies initially presenting in extra-abdominal/pelvic locations is unusual. This spread predominantly occurs with infectious processes to sites including the buttock, thigh, and calf. The routes of extension into adjacent anatomically weak compartments include the pelvic outlet, greater sciatic foramen, obturator foramen, inguinal or femoral canal, weak bones, or along nerves and blood vessels. Malignant neoplasms of the appendix, while extremely rare and accounting for only 0.4% of all gastrointestinal cancers, is one of the intra-abdominal pathologies that can spread via these routes. Adenocarcinoma of the appendix accounts for 10-20% of primary appendiceal tumors. They usually present as acute appendicitis or as a right lower quadrant abdominal mass when associated with a mucocele. We report the unique case of mucinous appendiceal adenocarcinoma in a 57-year-old male who initially presented with a right thigh mass secondary to extension of the neoplasm from the right lower quadrant through the femoral canal. A similar presentation of a mucinous appendiceal cystadenoma has been previously reported, however, to our knowledge, this is the first case of a malignant appendiceal tumor extending into the thigh. We review the literature and discuss imaging findings and treatment of this tumor.

Sister Mary Joseph Nodule as a Cutaneous Manifestation of Metastatic Appendiceal Adenocarcinoma: Case Report and Literature Review

Sister Mary Joseph nodule (SMJN) is an uncommon pattern of superficial periumbilical tumor metastasis, with the primary tumor most commonly associated with gynecological or gastrointestinal origins. This manifestation can represent extensive tumor development from any of the intra-abdominal or pelvic structures. Therefore, SMJN carries a poor prognosis, with a two-year survival rate of only 13.5 percent regardless of the etiology of primary cancer. In this case, a 67-year-old man with metastatic mucinous adenocarcinoma of the appendix involving the umbilicus presenting more than five years after the initial cancer diagnosis is reported. The features of patients with metastatic appendiceal carcinoma presenting as SMJN are also reviewed. With the inclusion of our patient, there are six patients who have documented SMJN due to appendiceal carcinoma: two men, two women, and two patients without demographic data. The patients ranged from the ages of 31 to 68 years, with a median age of 56.5 years at cancer diagnosis and 59 years at SMJN diagnosis. In 75 percent of the cases, SMJN was the initial clinical manifestation of a previously unsuspected appendiceal carcinoma and presented clinically one to seven months (median of five months) before the pathologic confirmation of the metastatic appendiceal carcinoma. The likelihood of SMJN presenting as the initial clinical feature of appendiceal cancer may increase in patients with extensive intraperitoneal metastasis in the form of pseudomyxoma peritonei or carcinomatosis. Therefore, the observation of a solitary umbilical nodule should prompt an investigation for an underlying primary neoplasm, as the prognosis after tumor metastasis to the umbilicus is poor.

[Duplication of the appendix revealed during a recurrent appendicitis syndrome]

La duplication appendiculaire est une malformation très rare. Elle se rencontre chez les enfants exceptionnellement chez les adultes. Sa découverte est souvent fortuite à l'occasion d'une laparotomie ou laparoscopie pour une autre pathologie. Nous rapportons un cas particulier d'un patient qui a bénéficié d'une appendicectomie il y'a 3 mois qui est admis aux urgences pour un syndrome appendiculaire récidivant avec aux explorations radiologique et chirurgicale la présence d'une appendicite rétrocoecale.

Comparison of model fit and discriminatory ability of M category as defined by the 7th and 8th editions of the tumor-node-metastasis classification of colorectal cancer and the 9th edition of the Japanese classification

Background

In transitioning from the 7th edition of the tumor‐node‐metastasis classification (TNM‐7) to the 8th edition (TNM‐8), colorectal cancer with peritoneal metastasis was newly categorized as M1c. In the 9th edition of the Japanese Classification of colorectal, appendiceal, and anal carcinoma (JPC‐9), M1c is further subdivided into M1c1 (without other organ involvement) and M1c2 (with other organ involvement). This study aimed to compare the model fit and discriminatory ability of the M category of these three classification systems, as no study to date has made this comparison.

Methods

The study population consisted of stage IV colorectal cancer patients who were referred to the National Cancer Center Hospital from 2000 to 2017. The Akaike information criterion (AIC), Harrell's concordance index (C‐index), and time‐dependent receiver operating characteristic (ROC) curves were used to compare the three classification systems. Subgroup analyses, stratified by initial treatment year, were also performed.

Results

According to TNM‐8, 670 (55%) patients had M1a, 273 (22%) had M1b, and 279 (23%) had M1c (87 M1c1 and 192 M1c2 using JPC‐9) tumors. Among the three classification systems, JPC‐9 had the lowest AIC value (JPC‐9: 10546.3; TNM‐7: 10555.9; TNM‐8: 10585.5), highest C‐index (JPC‐9: 0.608; TNM‐7: 0.598; TNM‐8: 0.599), and superior time‐dependent ROC curves throughout the observation period. Subgroup analyses were consistent with these results.

Conclusions

While the revised M category definition did not improve model fit and discriminatory ability from TNM‐7 to TNM‐8, further subdivision of M1c in JPC‐9 improved these parameters. These results support further revisions to M1 subcategories in future editions of the TNM classification system.

Concomitant occurrence of appendiceal mucocele and ulcerative colitis: Case reports

Background

Appendiceal mucocele (AM) is a rare disease, manifested by accumulation of mucus in appendiceal lumen. The role of ulcerative colitis (UC) in the occurrence of appendiceal mucocele is not known. However, it is suggested that AM may be a presentation of colorectal cancer in IBD patients.

Case Presentation

Here, we presented 3 cases of concomitant AM and ulcerative colitis. The first patient was a 55-year-old woman with 2-year history of left sided UC; the second person was a 52-year-old woman with 12-year history of pan-UC; and the third patient was a 60-year-old man with 11-year history of pan-colitis. They were all referred due to indolent right lower quadrant abdominal pain. Imaging evaluations suggested the presence of appendiceal mucocele and therefore, they all went under operation. Pathologic evaluation reported AM of mucinous cyst adenoma type; low-grade appendiceal mucinous neoplasm of appendix with intact serosa; and cyst-adenoma type AM for the three above-mentioned patients, respectively.

Conclusion

Although concomitant occurrence of AM and ulcerative colitis is rare, regarding the potential of neoplastic changes in AM, physicians must keep in mind the diagnosis of AM in UC patients with non-specific abdominal RLQ pain or bulged appendiceal orifice during colonoscopy.

A giant low-grade appendiceal mucinous neoplasm (LAMN) presenting as ileocecal intussusception: a case report

We report the rare case of a giant low-grade appendiceal mucinous neoplasm (LAMN), presenting as ileocecal intussusception. An 80-year-old woman presented in the emergency department of our institution with progressively worsening diffuse abdominal pain during the last 24 h. A CT scan revealed a giant abdominal mass (98.7 × 127.3 × 107.6 mm) with air-fluid level and imaging characteristics of ileocecal intussusception. An emergency exploratory laparotomy was performed, and a well-circumscribed cystic mass deriving from the appendix was found. A right hemicolectomy was performed, and the histopathological examination confirmed the diagnosis of LAMN. This report aims to raise awareness among surgeons and radiologists, about LAMNs as a differential diagnosis of right iliac fossa masses presenting as acute abdomen.

Incidental Finding of a Low-Grade Appendiceal Mucinous Neoplasm: A Case Study

Low-grade appendiceal mucinous neoplasms (LAMNs) are rare benign tumors of the appendix with possible life-threatening complications. A 25-year-old female patient presented to the emergency room with abdominal pain with symptoms concerning for acute appendicitis. After imaging, it was decided to proceed with an appendectomy. Final pathology showed low-grade appendiceal mucinous neoplasm. Due to their ability to mimic appendicitis, it is important to include LAMNs in the differential diagnosis for patients of all ages, as they can cause life-threatening pseudomyxoma peritonei (PMP). Although this case report highlights a rare condition, it should be on a general surgeon's differential to avoid potential long-term malignancies.

A Unique Case of Appendiceal Intussusception (Inversion): A Case in Bloom

A 40-year-old female patient presented to a secondary facility with dull lower abdominal pain and a persistent low-grade fever. Her laboratory results showed elevated inflammation markers. A CT scan revealed two abscesses in the lesser pelvic region in direct contact with the apex of the appendix, the posterior wall of the uterus, and the right-side appendages. The patient responded well to intravenous antibiotics, and an MRI scan revealed the cause to be an appendiceal rupture. The patient was scheduled for an appendectomy. The procedure started laparoscopically but had to be converted to an open one with a midline infra-umbilical incision in order to protect the right appendages. A standard appendectomy was conducted, and the histology report revealed rupture of the appendix with concomitant wall inversion in the context of fibrous adhesions as well as obstruction due to a fecalith. Patient recovery and follow-up were excellent. Acute appendicitis, while frequently encountered in surgical practice, can present a diagnostic conundrum when it manifests in an atypical manner. This unique form of inversion appeared to confer a protective role against peritonitis, primarily through the mechanism of obstruction occurring centrally to the rupture. We suggest that this case should be included in current classifications as a partial inversion of the appendix after rupture and inflammation.

Appendiceal Mucinous Neoplasm: A Case of an Incidental Finding

Appendiceal mucinous neoplasms (AMNs) are uncommon gastrointestinal tumors characterized by mucus accumulation in the appendix. Patients may complain of acute appendicitis-like symptoms with other alarming features, but approximately half of the cases of AMNs are found incidentally on imaging. Early diagnosis and management of these neoplasms are important to prevent malignant progression and complications such as bowel obstruction and pseudomyxoma peritonei. We report a case of a 28-year-old female who initially presented with vomiting and acute left lower abdominal pain radiating to the left flank. Computed tomography (CT) revealed a 1.5 mm stone in the left ureteral vesicular junction and a 2.3 x 2.4 x 5.2 cm cystic tubular mass at the base of the cecum, suspicious of an appendiceal mucocele. An elective laparoscopic appendectomy was performed on this admission, which was converted to a right hemicolectomy due to the pathologic finding of a focally high-grade AMN on intraoperative frozen specimen pathology. This report aims to provide an example of a case of an incidental AMN and how it was diagnosed and managed surgically. AMNs are rare tumors that originate from the appendix and can pose diagnostic and therapeutic challenges due to their diverse clinical presentations and variable histopathological features. The majority of cases of AMNs are discovered in middle-aged individuals (40-50 years of age) after an appendectomy is performed and examined by pathology. This case report aims to describe a rare presentation of a 28-year-old female patient with an incidental finding of AMN on a CT scan of the abdomen while being worked up for suspected nephrolithiasis. We will provide a comprehensive overview of a unique presentation of AMN, highlighting its clinical manifestations, diagnostic approach, and management strategies. We present the case of a 28-year-old female patient who presented to the emergency department with complaints of acute left lower quadrant abdominal pain radiating to the left flank and vomiting. After an initial assessment and workup, which included lab investigations and imaging, a diagnosis of unilateral hydronephrosis due to a calculus of the ureterovesical junction was made. However, there was also suspicion of an appendiceal mucocele, as evidenced by a CT scan of the abdomen and pelvis. On admission day one, under the care and management of the urology team, she passed the stone with complete resolution of the presenting symptoms. On hospital day two, she underwent an elective laparoscopic appendectomy followed by a right hemicolectomy due to findings of high-grade mucinous neoplasm on the resected frozen specimen near the base of the appendix. AMN was an incidental finding based on CT imaging and macroscopic findings, which was later confirmed by histopathological assessment and report.

Appendiceal Neoplasm: It's Never What It Seems

Appendiceal neoplasms are a rare and heterogeneous condition with a non-specific clinical presentation, often concealing intricate predicaments; hence they require complex and diverse management. The present case report aims not only to describe a less usual form of presentation and its orientation but also to provide a modest literature review in a rather demanding pathology.