DP25 Spindle cell haemangioma: when extensive clinical disease belies benign histology

Abstract

Spindle cell haemangioma (SCH) is a rare benign vascular tumour typically presenting as multiple nodules on the distal extremities. Although histologically benign, SCH may be locally recurrent and multifocal, posing diagnostic and management challenges. A 32-year-old Bangladeshi woman presented with a 4-year history of progressive nodules on the left hand and forearm, with tenderness over digital lesions. Examination revealed multiple purple nodules on the pulp of the left ring and little fingers, volar fourth web space, ulnar border of the hand, volar wrist and dorsoulnar distal forearm, extending proximally towards the elbow. The multi­focal distribution and proximal progression raised clinical concern for an aggressive vascular process. Magnetic resonance imaging (MRI) demonstrated multiple subcutaneous vascular lesions with incomplete contrast enhancement, suggestive of thrombosis within several lesions. Excision biopsies from the left index finger showed a well-circumscribed vascular proliferation composed of thick-walled vessels admixed with small, thin-walled vascular channels and spindle cells. A secondary population of vacuolated cells resembling adipocytes was noted. Immunohistochemistry was positive for CD31, with patchy CD34 staining; smooth muscle actin and desmin highlighted thick-walled vessels. Human herpesvirus-8 was negative, excluding Kaposi sarcoma and confirming the diagnosis of spindle cell haemangioma. Given the extensive, multifocal nature of the lesions and potential for recurrence, a conservative approach was adopted. The patient was referred for further evaluation with MRI and duplex imaging from shoulder to fingertip and multidisciplinary vascular team discussion. This case illustrates the diagnostic complexity and management considerations of multifocal spindle cell haemangioma, emphasizing the importance of imaging, histopathological correlation and multidisciplinary input in achieving optimal outcomes. Awareness of its characteristic but heterogeneous histological pattern, supported by targeted immunohistochemistry, is essential to avoid misdiagnosis as malignant vascular neoplasia and to guide appropriate management.