Haemangiopericytoma of the greater omentum: a rare tumour requiring long-term follow-up.

Haemangiopericytomas (HPC) are highly vascularized tumours located in any part of the body where capillaries can be found. Since 2002, they have been re-classified under the umbrella 'extrapleural Solitary Fibrous Tumour (SFT)' and the term HPC is nowadays used to describe a growth pattern rather than a clinical entity. Their biological behaviour varies and they require a long-term follow-up since they may recur or metastasise several years after successful treatment. We present the case of a gentleman with HPC of the greater omentum initially appeared in 1998. HPC rarely develops in the greater omentum and only 20 cases have been described in the literature till today. Despite complete excision the mass re-appeared in 2011 and 2017, 13 and 19 years after initial treatment. Surgical management included en bloc excision of three lesions along with greater omentum. No further treatment was required.