Low-grade mucinous appendiceal neoplasm mimicking an ovarian lesion: A case report and review of literature

Contrast-enhanced ultrasonography findings of LAMNs with peritoneal and splenic metastases: a case report and literature review

Low-grade appendiceal mucinous neoplasms (LAMNs) are rare appendiceal tumors that are primarily diagnosed using computed tomography(CT) enhancement and magnetic resonance imaging (MRI). Herein, we report the sonographic features, especially for contrast-enhanced ultrasound (CEUS), of a 70-year-old female with an unusual LAMN metastasizing to the peritoneum and spleen. The patient had a right pelvic mass 2 days prior to presentation. Two-dimensional (2D) ultrasound revealed a mixed cystic-solid mass in the right lower abdomen and spleen parenchyma; CEUS showed heterogeneous enhancement in both areas, suspected to be a mucinous mass. CT enhancement and MRI findings revealed concurrent findings. Histopathologically, LAMN lesions were confirmed in the appendix, spleen, and peritoneum of the specimens obtained during exploratory laparoscopy. No recurrences were reported at three years postoperatively. LAMN lesions may metastasize to abdominal organs, and imaging examinations are essential for diagnosis. This study presents major ultrasonography and CEUS findings for the diagnosis of LAMNs.

Low grade appendiceal mucinous neoplasm metastatic to the ovary: A case report and intraoperative assessment guide

INTRODUCTION

Incidence of low grade appendiceal mucinous neoplasm is increasing. Preoperatively, it may present similarly to primary ovarian malignancy. This case report describes a case of presumed ovarian malignancy with final pathologic diagnosis of low grade appendiceal mucinous neoplasm. We also propose several surgical strategies to approach this conundrum.

PRESENTATION OF CASE

A postmenopausal woman with abdominal pain was found to have a 30 cm abdominopelvic mass with elevated CA-125 and CEA presumably a primary ovarian malignancy. During surgical staging, intraoperative findings were notable for an appendiceal mass. Intraoperative surgical oncology consultation recommended appendectomy for diagnostic purposes. Following primary surgery and final pathologic diagnosis, she underwent cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

DISCUSSION

Low grade appendiceal mucinous neoplasm should be within the differential diagnosis of gynecologic surgeons when presented with a patient with large volume ascites and biopsy of acellular mucin. Intraoperatively, an abnormal appearing appendix with normal appearing gynecologic structures should trigger suspicion for appendiceal rather than ovarian origin. Preoperative symptoms, imaging studies, tumor markers, and frozen section pathology may not be able to differentiate between appendiceal and epithelial ovarian malignancies.

CONCLUSION

A recognition of mucinous material and abnormal appearing appendix should prompt the surgeon to consider performing an appendectomy to obtain primary pathologic diagnosis. A high level of suspicion could better optimize the patient for a joint case with the appropriate surgeons. Given the documented disguise of low grade appendiceal mucinous neoplasm as primary ovarian cancer and its increasing incidence, diagnosis and general understanding of treatment should be understood.

Appendiceal mucocele masquerading as an epithelial borderline ovarian tumor: a case report and literature review

Appendiceal mucocele is a rare mucin-producing neoplasm of appendiceal origin. Due to its location and imaging findings, appendiceal mucocele is easily confused with tumors of the right adnexa. We present a rare case of a patient initially misdiagnosed with an ovarian tumor intraoperatively diagnosed as an appendiceal mucocele and successfully treated. A 66-year-old postmenopausal woman was admitted to the gynecology department for an asymptomatic pelvic mass. Preoperative pelvic imaging showed an 8-cm cystic mass. Exploratory laparoscopy for the suspected epithelial borderline tumor from the right ovary revealed a cystic mass in the right pelvic area and normal uterus, fallopian tubes, and ovaries. Intraoperative consultation with the general surgery department confirmed the appendiceal origin. Laparoscopic appendectomy was performed. Histopathological examination confirmed a low-grade mucinous neoplasm of appendiceal origin. The patient was discharged on a postoperative day 5 without complications. The outpatient follow-up performed 1 month later showed no evidence of disease progression. Despite the use of advanced diagnostic tools, appendiceal mucocele may be confused for ovarian malignancies. Because the clinical features of appendiceal mucocele are nonspecific, clinicians and radiologists know the specific imaging findings. A multidisciplinary approach including general surgery, gynecology, and radiology is required for preoperative diagnosis and treatment.