Prerequisites for sample material

A small biopsy (e.g., ultrasound-guided puncture, CT-guided puncture) may be sufficient to make a histologic diagnosis of a vascular tumor or vascular malformation. A larger sample obtained surgically is not always necessary. The samples should be fixed in buffered formalin and sent to the pathology department without delay. Overlong fixation in formalin may result in DNA fragments that are not long enough for any additional molecular pathological investigations that may be necessary (e.g., PIK3CA mutation analysis). The processing of samples in pathology is standardized.

Hematoxylin- and eosin stain and an Elastica van Gieson staining should be performed routinely first.