Mesenteric cyst: non-specific abdominal pain in the emergency department

Description A normally healthy woman in her 20s presented to the emergency department with a 2-week history of intermittent, non-specific abdominal pain. She had 24 hours of nausea and two episodes of shivering without documented fever. She reported no other gastrointestinal, urinary or gynaecological symptoms. Physical examination revealed a large, firm mass in the left iliac fossa and hypochondrium with mild tenderness. Observations were normal, venous blood gas was unremarkable and urinary hCG negative. A CT of the abdomen and pelvis with contrast was performed (figures 1 and 2). Mesenteric cysts are rare intra-abdominal tumours that present in three main ways; (1) asymptomatically, (2) with abdominal pain and (3) as an acute abdomen.1 Given the vague nature of the patient’s symptoms, physical examination was key to diagnosis, with a mass palpable in up to 61% of patients with a mesenteric cyst.2 CT or ultrasound are the imaging modalities of choice (figures 1 and 2).1 2 Treatment is generally surgical excision because a small percentage proves to be malignant, while complications of non-removal/diagnosis include rupture, haemorrhage, infection and torsion.1 2 Differentials for a large mass in the left lower quadrant include ovarian tumours which can present with similarly vague abdominal symptoms. An ovarian mucinous cystadenoma is the closest differential based on the CT imaging given they can also become extremely large.3 Most ovarian tumours are benign, but a malignant ovarian tumour is a sensible differential from the initial assessment and needs to be excluded with imaging. If an abdominal mass is felt, it needs to be distinguished between an abdominal wall mass and an intra-abdominal mass.4 During physical examination, abdominal wall masses become more notable when abdominal wall muscles are tensed, whereas the opposite is true of intra-abdominal masses.4 Intra-abdominal masses usually align with the anatomy, that is, a right upper quadrant mass will likely involve a liver, gallbladder or pancreatic pathology4 5 (figure 3, table 1). Table 1. | Intra-abdominal mass | | | Hepatomegaly | Right upper quadrant. Size-dependent—can be palpable in the epigastrium or left hypochondrium too. Smooth versus Irregular cause dependent. Palpable liver may be physiological.5 | | Splenomegaly | Left upper quadrant. Cannot get above it. Smooth. Can spread across the midline. Dull to percussion. Moves with inspiration. ‘Notch’ felt medially.5 | | Kidney—cysts/malignancy | Flank/lumbar region. Ballotable. Can be an irregular surface. Moves with inspiration.5 | | Abdominal aorta aneurysms | Central. Pulsatile. >3 cm diagnostic for men (lower in women). Poor sensitivity palpation alone.7 | | Faeces | Left lower quadrant (usually). Indentable. Disappears after defecation.5 | | Mesenteric cyst | Anywhere in the abdomen. Can become very large. Not always palpable.2 | Abdominal wall masses can include hernias, cystic masses, fat-containing masses (eg, a lipoma) or solid masses4 6 (table 2). Table 2. | Abdominal wall mass | | | Hernia | Reducible. Found at abdominal wall openings. Cough impulse positive.5 | | Cystic/fluid | Consider seroma or abscesses if post-surgery. Can include haematoma.6 | | Solid | Desmoid tumour most common abdominal wall mass. Metastases a differential. Can be endometriosis in menstruating women.6 | | Fat-containing | Lipoma most common mass. Other differentials are arteriovenous malformations and liposarcomas.6 | Learning points. This case highlights the importance of a thorough physical examination—a crucial diagnosis and need for imaging would have been missed otherwise. While rare, mesenteric cysts can explain vague abdominal symptoms and should be considered by clinicians in patients with an abdominal mass. Footnotes Contributors: The following authors were responsible for drafting of the text, sourcing and editing of clinical images, investigation results, drawing original diagrams and algorithms and critical revision for important intellectual content: PD and RR. The following authors gave final approval of the manuscript: PD and RR. Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors. Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy. Competing interests: None declared. Provenance and peer review: Not commissioned; externally peer reviewed. Ethics statements Patient consent for publication Consent obtained directly from patient(s). References - 1.Tan JJ-Y, Tan K-K, Chew S-P. Mesenteric cysts: an institution experience over 14 years and review of literature. World J Surg 2009;33:1961–5. 10.1007/s00268-009-0133-0 [DOI] [PubMed] [Google Scholar] - 2.de Perrot M, Bründler M-A, Tötsch M, et al. Mesenteric cysts. Dig Surg 2000;17:323–8. 10.1159/000018872 [DOI] [PubMed] [Google Scholar] - 3.Goumalatsou C. Gynaecology. In: Baldwin A, ed. 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