Appendiceal tumors are rare lesions that may not be easily differentiated from primary ovarian lesions preoperatively, despite the use of advanced diagnostic methods by experienced clinicians.

A 59-year-old G2P2 woman, with chronic pelvic pain, underwent a pelvic ultrasound that revealed an adnexal mass measuring 58 mm × 34 mm × 36 mm, with irregular borders, heterogeneous echogenicity, no color Doppler vascularization and without acoustic shadowing. Normal ovarian tissue was visualized in contact with the lesion, and it was impossible to separate the lesion from the ovary by applying pressure with the ultrasound probe. Ascites, peritoneal metastases or other alterations were not observed. With the international ovarian tumor analysis ADNEX model, the lesion was classified as a malignant tumor (the risk of malignancy was 27.1%, corresponding to Ovarian-Adnexal Reporting Data System category 4). Magnetic resonance imaging confirmed the presence of a right adnexal mass, apparently an ovarian tumor measuring 65 mm × 35 mm, without signs of invasive or metastatic disease. During explorative laparotomy, normal morphology of the internal reproductive organs was noted. A solid mobile lesion involved the entire appendix. Appendectomy was performed. Inspection of the abdominal cavity revealed no signs of malignant dissemination. Histopathologically, the appendiceal lesion corresponded to a completely resected low-grade mucinous appendiceal neoplasm (LAMN).

The appropriate treatment and team of specialists who should provide health care to patients with seemingly adnexal lesions depend on the nature (benign vs malignant) and origin (gynecological vs nongynecological) of the lesion. Radiologists, gynecologists and other pelvic surgeons should be familiar with the imaging signs of LAMN whose clinical presentation is silent or nonspecific. The assistance of a consultant specializing in intestinal tumors is important support that gynecological surgeons can receive during the operation to offer the patient with intestinal pathology an optimal intervention.

• Adnexal mass
• Appendiceal neoplasm
• Diagnostic imaging
• Pelvic neoplasm
• Adnexal diseases
• Pelvic neoplasm
• Case report

•

Equivocal signs and symptoms along with anatomical position of appendiceal mucinous neoplasm (AMN) makes it difficult to diagnose.

Appendiceal mucinous neoplasm is a rare type of appendiceal tumors which can present in a variety of symptoms and is difficult to diagnose. Preoperative diagnosis depends mainly on diagnostic imaging such as ultrasonography and computerized tomography (CT) scan. This uncommon case report discusses an appendiceal mucinous neoplasm mimicking a left adnexal mass on presentation, physical examination and diagnostic imaging findings.

This is a 61-year-old female found to have a large left adnexal mass during follow up ultrasonography. The patient refused further imaging, and during laparotomy, she was found to have an appendicular mucocele with normal left and right ovaries.

Appendectomy was done and the final pathology came as appendiceal mucinous neoplasm. Her post-operative course and 3 years follow up were uneventful.

The equivocal signs and symptoms along with the anatomical position of appendiceal mucocele makes it difficult to diagnose and can mimic other types of tumors. Therefore, it should be considered in the deferential diagnosis of lower abdominal and pelvic masses.

• Appendiceal mucinous neoplasm
• Appendix
• Case report
• Mimicking ovarian tumor
• Misdiagnose
• Mucocele
• Pelvic ultrasonography

• echinococcosis
• mucinous cystadenoma
• mucocele