issue ▁via ▁col lagen ▁fib ros is . ▁The ▁decrease ▁in ▁h emat opo iet ic ▁t issue ▁imp airs ▁the ▁patient ' s ▁ability ▁to ▁generate ▁new ▁blood ▁cells , ▁resulting ▁in ▁progress ive ▁p ancy t open ia , ▁a ▁short age ▁of ▁all ▁blood ▁cell ▁types . ▁However , ▁the ▁pro l ifer ation ▁of ▁fib ro bl asts ▁and ▁de position ▁of ▁col lagen ▁is ▁a ▁secondary ▁phenomen on , ▁and ▁the ▁fib ro bl asts ▁themselves ▁are ▁not ▁part ▁of ▁the ▁ab normal ▁cell ▁clone . ▁ ▁In ▁primary ▁my el of ib ros is , ▁progress ive ▁sc arring , ▁or ▁fib ros is , ▁of ▁the ▁b one ▁mar row ▁occurs , ▁for ▁the ▁reasons ▁out lined ▁above . ▁The ▁result ▁is ▁extr amed ull ary ▁h emat opo ies is , ▁i . e . ▁blood ▁cell ▁formation ▁occurr ing ▁in ▁sites ▁other ▁than ▁the ▁b one ▁mar row , ▁as ▁the ▁ha em opo etic ▁cells ▁are ▁forced ▁to ▁migr ate ▁to ▁other ▁areas , ▁particularly ▁the ▁li ver ▁and ▁s ple en . ▁This ▁causes ▁an ▁en larg ement ▁of ▁these ▁org ans . ▁In ▁the ▁li ver , ▁the ▁ab normal ▁size ▁is ▁called ▁he pat om eg aly . ▁En larg ement ▁of ▁the ▁s ple en ▁is ▁called ▁spl en om eg aly , ▁which ▁also ▁cont ributes ▁to ▁causing ▁p ancy t open ia , ▁particularly ▁th rom b oc yt open ia ▁and ▁an emia . ▁Another ▁comp