Giant low-grade appendiceal mucinous neoplasm: A case report

Incidental appendiceal neoplasms: Single-centre results

BACKGROUND

Histopathological examination of appendectomy specimens may reveal malignancies. Based on these results, either appendectomy is sufficient or sometimes a further treatment protocol can be needed. In this study, malignancy-diagnosed cases on appendectomy specimen were examined.

METHODS

Patients who underwent appendectomy between January 2013 and December 2018 with a pre-diagnosis of acute appendicitis were evaluated retrospectively and those cases with malignancy were included in the study. Patients' age, sex, tumor type, tumor diameter, tumor grade, tumor localization, surgical margin, Ki-67 index, state of lymphovascular invasion, state of peri-neural invasion, and follow-up period duration were recorded.

RESULTS

On examination of 2336 appendectomy specimens, 16 patients (0.7%) were found to have neuroendocrine tumors (NET), 11 patients (0.5%) were found to have low-grade mucinous neoplasm (LAMN), and five patients (0.2%) were found to have primary appendix carcinomas. Appendix tumors usually present with acute appendicitis symptoms. Despite re-operation with right hemicolectomy (RHC) being required in the treatment of adenocarcinoma cases, appendectomy provides adequate treatment in most cases with NET and LAMN. With these tumors, which usually have a benign prognosis, it is important to perform the necessary screening in the postoperative period and not to interrupt follow-up.

LAMN as a differential diagnosis for abdominal pain: a case report from Syria

Low-grade appendiceal mucinous neoplasms (LAMNs) are papillary or flat mucinous tumors with low-grade cytologic atypia found in <0.3% of appendectomy specimens among older population. They are the most frequent source of pseudomyxoma peritonei. They can be easily misdiagnosed, due to unspecific symptoms, with acute appendicitis, retroperitoneal tumors or adnexal mass. Macroscopically, the appendix may appear normal or be variably dilated. Microscopic study determines whether the studied specimen is LAMN or mucinous adenocarcinomas. We report a 77-year-old patient presented with 15-day abdominal pain accompanied with chills and hyperthermia. Decision was made for right hemicolectomy as a result of the findings on ultrasound and computed tomography scan. Diagnosis was made after the pathologic study, which revealedLAMN.

OUP accepted manuscript

Primary neoplasm of the appendix is often diagnosed incidentally after an appendectomy. Low-grade appendiceal mucinous neoplasms (LAMNs) make up a small portion of these neoplasms. We present a rare case of a patient with a slow-growing LAMN causing urinary retention and constipation. The mass was initially found incidentally 25 years prior, but the patient declined further workup since he was asymptomatic at that time. The patient experienced progressively worsening abdominal discomfort related to urinary retention and difficulty in evacuating his bowels. Imaging identified a large abdominal mass (19.3 × 8.7 × 13.5 cm). The mass was surgically resected. Pathology was consistent with a LAMN. In general, an incidental finding of an abdominal mass should be further investigated regardless of symptomology. Patients should be educated about the potential of malignancy and the need for a major abdominal surgery in the future if they choose not to have a mass further evaluated.

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.

Incidental diagnosis of a low-grade mucinous appendicular neoplasm: A case report

Introduction and importance

Low-Grade Appendiceal Mucinous Neoplasms (LAMN) are noninvasive epithelial tumors of the appendix. Symptomatology is unspecific and can simulate appendicitis. The multidisciplinary approach for the correct diagnosis and management of this kind of tumor is important, as the prognosis depends on it.

Presentation of the case

A 70-years-old man with an appendiceal picture is presented. McBurney and Blumberg's signs were found and the Echography has reported an acute appendicitis. He underwent laparoscopic surgery, founding a Tumor in the Cecum of 10 × 5 cm. We decided to perform an appendectomy with a total cecectomy. The pathological diagnosis was a LAMN. Ten months later, a Computed Tomography (CT) Scan control was performed reporting no evidence of Tumoral activity or Distance Metastasis, neither pseudomyxoma peritonei (PMP) evidence.

Discussion

LAMN has been a very controversial tumor. The definitive management is appendectomy. There are controversies about the laparoscopic and open approach, and when there are positive margins. The stage was a pTis (LAMN) pNx according to the 8th edition of the American Joint Committee on Cancer (AJCC). The prognosis depends on the tumoral stage and the presence of PMP. In our case, we have performed a CT scan follow up and there was no Tumoral activity or Distance Metastasis, neither PMP evidence.

Conclusion

LAMN is a very interesting and rare tumor. The diagnosis of this case was a real challenge. Our management was simple due to the tumoral stage. Pathology played a very important role in treatment and prognosis.

•

The clinical presentation of LAMN is unspecific, it can simulate an appendicitis.

•

Surgical approach can be by laparoscopy depending on the tumoral staging.

•

The diagnosis is crucial to determine the management and prognosis.

•

The approach must be multidisciplinary and cooperative between medical departments.

Low grade appendiceal mucinous neoplasm mimicking an ovarian cyst: A case report

•

Appendiceal mucocele defines as an intraluminal dilation of the appendix in response to mucin accumulation.

•

This condition overall is very rare with a 0.2–0.3% incidence of all appendectomy specimens.

•

It's more common in the females with a 4 to 1 ratio.

•

Appropriate diagnosis and management of appendiceal mucocele prevent complications such as pseudomyxoma peritonei.

Introduction

Appendiceal mucocele (AM) is a very rare neoplasm with an incidence of 0.2–0.3% of all appendectomy specimens. AM usually defined as an intraluminal dilation of the appendix in response to mucin accumulation. The preoperative diagnosis is difficult and can be misdiagnosed to any of the other differential diagnosis especially in female patients. If it is suspected, imaging modalities and colonoscopy can be helpful as a guide for the right surgical approach.

Presentation of case

A 41-year-old lady who found to have an appendicular tumor discovered incidentally on magnetic resonance imaging (MRI) of the abdomen during a follow-up in the referral hospital for persistent right lower quadrant abdominal pain with enlarging right ovarian cyst for 2 years. MRI revealed a sizeable cyst measuring 7 × 4 × 3 cm in the right iliac fossa (RIF) region with high suspicion of an AM. The patient was managed with open right limited hemicolectomy. The patient was diagnosed as a well-differentiated low-grade AM neoplasm with stage 0 (pTis, pN0, M0) based on the 8th edition of the American Joint Committee on Cancer (AJCC) Staging System. The patient had an uneventful recovery and advised for regular follow-up of at least 5 years.

Discussion

AM is a very rare neoplasm. The imaging modalities that can be diagnostic methods are the abdominal ultrasonography (US), transvaginal US, abdominal computed tomography (CT) and abdominal MRI. Fine needle aspiration must be avoided as the risk of perforation is high that will lead to dissemination of the mucinous material causing a serious complication called pseudomyxoma peritonei. Laparotomy is superior on laparoscopy as the risk of perforation is lower in laparotomy.

Conclusion

The presentation of AM is usually not specific, because of its anatomic position. Physicians should consider it in the differential diagnosis of persistent enlarging ovarian cyst or adnexal mass.