Retroperitoneal haemangioma masquerading as recurrence of well-differentiated neuroendocrine tumour - a cautionary note

Q: Why can haemangiomas be mistaken for neuroendocrine tumour recurrence on 68Ga-DOTATATE PET/CT?

Haemangiomas may show increased gallium uptake due to vascularity and tracer-related factors, which can mimic residual or recurrent neuroendocrine tumour on imaging.

Q: What imaging findings prompted surgery in this case?

CT enterography identified an enhancing para-psoas nodule, and 68Ga-DOTATATE PET/CT demonstrated a single intensely avid lesion at the same location.

Q: What did histology reveal after excision of the retroperitoneal lesion?

Histological evaluation showed an intravascular capillary haemangioma, with no evidence of residual or recurrent neuroendocrine tumour.

Sep 28, 2026

Uploaded by Patrick

A clinical case report describes a 42-year-old man with a history of a fully resected, well-differentiated appendiceal neuroendocrine tumour who later developed a para-psoas retroperitoneal lesion. Postoperative 68Ga-DOTATATE PET/CT showed an intensely gallium-avid mass interpreted as possible residual, recurrent, or metastatic disease. Multidisciplinary discussion led to surgical excision, and histology demonstrated an intravascular capillary haemangioma rather than neuroendocrine tumour. Follow-up imaging confirmed disappearance after surgery.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages4

Reading Time10 min

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Background

Case history

Discussion

CASE REPORTS DOI: 10. 1308/rcsann.2025.0009 Retroperitoneal haemangioma masquerading as recurrence of well-differentiated neuroendocrine tumour: a cautionary note Gallium 68-DOTATATE positron emission tomography scanning is the cornerstone of nuclear medicine imaging for neuroendocrine tumours. Previous reports have demonstrated the potential for vertebral haemangiomata to mimic neuroendocrine skeletal metastases. We present the case of a 42-year-oldman with a history of well-differentiated neuroendocrine tumour of the appendix, identified incidentally following emergency appendicectomy. Postoperative 68Ga-DOTATATE positron emission tomography/computed tomography scanning revealed an intensely gallium-avid retroperitoneal lesion adjacent to the right psoas muscle. Surgical excision of this lesion was recommended following multidisciplinary team discussion. Histological evaluation of the resected lesion revealed an intravascular capillary haemangioma. Haemangiomas can mimic residual or recurrent neuroendocrine tumour based on gallium avidity, and this should be considered in atypical cases. Keywords: Retroperitoneal haemangioma; Neuroendocrine tumour; 68Ga-DOTATATE PET/CT; Gallium-avid Background Neuroendocrine tumours (NETs) of the appendix are rare neoplasms, often discovered incidentally following appendicectomy for suspected acute appendicitis.1 Typically well differentiated, these tumours generally have a favourable prognosis and according to current guidelines, patients with tumours <1cm in size, completely excised (R0) and exhibiting no high-risk histological features require no surveillance. The North American Neuroendocrine Tumor Society and European Neuroendocrine Tumour Society guidelines describe the speciﬁc indications for surveillance imaging in the context of appendiceal NETs.2 Somatostatin receptor (SSR) imaging, e.g. gallium 68-DOTATATE positron emission tomography/computed tomography (68Ga-DOTATATE PET/CT), studies are commonly used for the detection of metastatic or recurrent disease in patients with well-differentiated NETs owing to their high sensitivity and speciﬁcity for SSR-positive tissues.3 In the literature, other benign and malignant conditions can express SSR including vertebral haemangiomas, which have been reported to demonstrate increased uptake on 68Ga-DOTATATE PET/CT imaging, perhaps because of their rich vascularity, their expression of SSRs or high capillary permeability.4–8 This can theoretically lead to false-positive ﬁndings in patients undergoing surveillance for NETs, because the increased tracer accumulation mimics metastatic or recurrent disease. In this case report, we describe such a situation involving a 42-year-old man with a history of appendiceal NET. Case history The 42-year-old man in this case study underwent a laparoscopic appendicectomy in February 2023 in Uganda for perforated appendicitis. Histopathological assessment revealed a fully resected (R0) 4mm well-differentiated NET of the appendiceal tip. Final staging conﬁrmed this as a pT2 tumour with no evidence of lymphovascular or perineural invasion, with a Ki-67 proliferation index of <1% . The postoperative course was complicated by intra-abdominal collections for which he underwent a laparotomy and washout. We are not aware of any further CT imaging performed prior to emergency laparotomy and washout, and this appears to have been undertaken on clinical grounds alone. About one year later, the patient presented to our hospital having experienced lower abdominal discomfort a few weeks prior. Physical examination found him to be generally well, with a healed midline incision and healed AM AbdelDayem1,2 S Navalkissoor3 TV Luong1 M Caplin3 R Mirnezami1 1Royal Free London NHS Foundation Trust, UK 2Cairo University, Egypt 3ENETS Centre of Excellence, UK Correspondence to: Reza Mirnezami [reza.mirnezami@nhs.net](reza.mirnezami@nhs.net) This article reflects the opinions of the auth

FAQs

Why can haemangiomas be mistaken for neuroendocrine tumour recurrence on 68Ga-DOTATATE PET/CT?

Haemangiomas may show increased gallium uptake due to vascularity and tracer-related factors, which can mimic residual or recurrent neuroendocrine tumour on imaging.

What imaging findings prompted surgery in this case?

CT enterography identified an enhancing para-psoas nodule, and 68Ga-DOTATATE PET/CT demonstrated a single intensely avid lesion at the same location.

What did histology reveal after excision of the retroperitoneal lesion?

Histological evaluation showed an intravascular capillary haemangioma, with no evidence of residual or recurrent neuroendocrine tumour.

Sep 28, 2026

Uploaded by Patrick