[Appendiceal mucocele disclosed by a psoas tumor. Apropos of a case]

Area of Science:

• Gastroenterology
• Surgical Pathology
• Abdominal Imaging

Background:

• Mucocele of the appendix is a rare appendiceal neoplasm.
• Rupture of an appendiceal mucocele into adjacent structures, such as the psoas muscle, is exceptionally uncommon.
• This presentation can mimic other retroperitoneal or psoas masses.

Observation:

• A 77-year-old male presented with findings suggestive of a psoas tumor on imaging (ultrasonography and computed tomography).
• Preoperative differential diagnoses included hydatid cyst, psoas tumor, or retroperitoneal mass.
• Surgical exploration revealed a ruptured appendiceal mucocele extending into the psoas muscle.

Findings:

• The definitive diagnosis was an appendiceal mucocele that had ruptured into the psoas.
• Appendicectomy was performed as the primary surgical intervention.
• The patient experienced an uneventful postoperative recovery and remained disease-free at 3-year follow-up.

Implications:

• This case underscores the importance of considering rare appendiceal pathologies in the differential diagnosis of psoas masses.
• Effective surgical management, including appendicectomy, can lead to favorable outcomes.
• Further discussion on diagnostic and therapeutic challenges associated with this rare entity is warranted.