腎上腺血管瘤：罕見病例報告

沈毓明、王百孚

彰化基督教醫院泌尿外科

Adrenal hemangioma: A Rare Case Report

Yu-Ming Shen, Pai-Fu Wang

Division of Urology, Department of Surgery, Changhua Christian Hospital

Introduction

Adrenal hemangioma is a rare benign vascular tumor, accounting for less than 1% of adrenal neoplasms and reported in only a limited number of cases worldwide. It is most commonly detected incidentally during imaging studies and is typically non-functioning and asymptomatic. However, preoperative diagnosis remains challenging due to nonspecific radiologic features, frequently mimicking malignant tumors such as adrenocortical carcinoma, pheochromocytoma, or metastasis. Consequently, many patients undergo surgical resection for definitive diagnosis, highlighting the clinical dilemma in distinguishing benign from malignant adrenal masses.

Case presentation

A 51-year-old woman with a prior history of papillary thyroid carcinoma treated with bilateral total thyroidectomy was found to have an incidental adrenal lesion during health examination. Abdominal contrast-enhanced CT revealed a 3.3 cm heterogenous non-enhancing ovoid mass within the left adrenal gland (Figure 1). Endocrine assessment showed no biochemical evidence of hormonal activity.

Owing to the inconclusive imaging features and the need to exclude malignancy, surgical intervention was undertaken. The patient underwent retroperitoneoscopic partial adrenalectomy. Intraoperative findings demonstrated a cystic mass located at the adrenal tail without an identifiable feeding vessel. Histological analysis confirmed a vascular lesion composed of dilated, interconnected channels lined by flattened endothelial cells. Immunohistochemical staining was positive for CD31 and CD34 and negative for cytokeratin, establishing the diagnosis of adrenal hemangioma. The patient recovered uneventfully, and no recurrence was observed during follow-up.

Discussion

Adrenal hemangiomas are rare benign vascular tumors that pose significant diagnostic challenges due to their overlapping imaging features with malignant adrenal lesions. Most patients are asymptomatic and diagnosed incidentally, with approximately 70% discovered during imaging for unrelated conditions. Their radiologic appearance is variable and may include heterogeneous enhancement, calcifications, necrosis, or hemorrhage, all of which can mimic adrenocortical carcinoma or metastatic disease.

Although certain imaging characteristics, such as peripheral nodular enhancement with progressive centripetal fill-in, may suggest hemangioma, these findings are not always present, making definitive preoperative diagnosis difficult. Furthermore, biopsy is generally avoided due to the risk of bleeding and potential catecholamine crisis if pheochromocytoma cannot be excluded.

Management strategies for adrenal incidentalomas are largely based on tumor size, functional status, and suspicion of malignancy. Current literature and clinical practice guidelines suggest surgical resection for adrenal masses larger than 4 cm or those with indeterminate imaging features. Even for smaller lesions, surgery is often pursued when malignancy cannot be confidently excluded. Histopathological examination remains the gold standard for diagnosis, typically demonstrating dilated vascular channels lined by endothelial cells with positive staining for vascular markers such as CD31 and CD34.

Conclusion