What's the problem when a vein in palm get swollen? Since 6 Months i can feel it pulsing every now and then. (photos)

It is unusal to have an enlarged vein in the palm. It could be a bruise but bruises dont pulsate. It could be a vein aneurism or venous malformation. I would consult a venous or vascular specialist. Wishing your father a the best.

You need a doppler ultrasound of the palm of the hand and this will tell if it is a venous structure, arterial structure (aneurysm) or AV malformation. I suppose if you have a job with repetitive injury to the hand (construction) work, this could form.Nevertheless, it is very important to get this looked at by a vascular surgeon or hand surgeon. Hand surgeons are orthopedic specialists and may not know how to deal with vascular structures in the hand other than reimplanting amputated hands.You live in Lebanon and I am sure there are 'war trained and experienced' vascular surgeons who can very easily deal with this issue. 

I would do an ultrasound of the hand vein to make sure that it is just a vein and does not have a communication with an artery.  If it is a vein that is pulsating because it is over an artery then it can be treated by sclerotherapy preferably or microphlebectomy. If it communicates with an artery then ligation may be necessary.  Either way, it can be treated.