Spontaneous digital arteriovenous malformation in a 28‐year‐old pregnant female

Histological findings were consistent with Becker's naevus in ail three patients. Skeletal survey did not reveal any abnormality. Ipsilateral breast hypoplasia has been reported so far in only eight women with Becker's naevus.^'' It has been explained on the basis of high androgen-receptor activity in pigmented skin and non-detectable receptor activity on contralateral is rare and poorly reported. It was initially diagnosed as a pyogenic granttloma. We would like to draw attention to the development of such lesions in pregnancy. A 28-yeEir-o!d female iO weeks pregnant with twins presented with u 12-week history of a lesion increasing in size over the right index linger iFig. 11. There was no hist{)ry of trauina or a pre-existing vascular niallbrniation at this site. Initially not painful it was becoming uncomfortable at time of presentation. A tense purple pulsatile mass was found over the anteroradial aspect of the right index linger. It was I cm in diameter and ()'5cm elevated. The overlying skin was thin and involved. Distal sensation and perfusion were normal. The lesion was excised under local anaesthetic using a digital tourniquet. The main radial neurovascular bundle was not involved although multiple minor vessels from both sides of the linger were feeding the lesion. It was excised and the defect covered with a full thickness hypothenar Wolfe graft. Histology (Fig. 21 confirmed a vascular lesion with both larger arteries and veins and smaller endothelial lined spaces consistent with an arteriovenous malformation. Arteriovenoas malformations (AV'Ms) may be congenital or acquired. Fistulae can result from penetrating trauma which may be minor and possibly be forgotten by the patient. The development of the areola and nipple at puberty in both sexes is oestrogen-dependent as is the development of breast in females. The hypoplasia of areola in our patient can be explained on the basis of androgen-receptor excess in the region of Becker's naevus. thus disturbing the androgenoestrogen balance at the affected site. Fach of our patients has areolar hypoplasia and Becker's naevus in tbe same area, a linding which has not yet been reported in the literature.