(6)  Myoma  occurs  as  leiomyoma  (smooth  non-striated  muscle  cells)  or  as
rhabdomyoma  (striated  muscle  elements).  Ij^otnyoma  is  most  common  in
the  uterus  (where,  owing  to  the  quantity  of  fibrous  tissue  present,  it  is  called
fibromyoma),  gastrointestinal  tract,  and  prostate.  It  is  encaiisulatcd,  firm
in  consistency,  a-ddish  on  section,  and  frequently  stratified  or  concentric  in
arrangement.  Among  the  secondary  changes  which  may  occur  are  inflam-
mation, ulceration  or  necrosis,  and  cystic,  fatty,  myxomatous,  or  calcareous
degeneration.  It  may  be  excessively  supplied  with  large  blood  vessels
{myoma  cavemosum).  Rhabdomyoma  is,  as  a  rule,  chiefly  sarcomatous,
the  proportion  of  striped  muscular  fiber  being  small;  it  is  rare,  mostly  con-
genital, and  is  found  in  the  kidney,  ovary,  and  testicle.  The  treatment  is
excision.
(7)  Hemangioinata,  or  tumors  composed  of  blood  vessels,  e.^ist  as  the  (a)
simple  nnms.or  angioma  ttlangitctalieum,  (b)  angioma  cavemosum,  (c)  plexi-
jorm  angioma.
(a)  Simple  neims  consists  of  dilated  capillaries,  arterioles,  and  venules.  When
the  arterioles  are  princi[)ally  involved,  the  gmwth  is  bright  red  (nevus  jlammcus,
or  strawheny  mark);  when  the  venules  predominate,  the  color  is  dark  red
{nei'us  venosus,  or  port  wine  mark).  These  tumors  arc  slightly  elevated,  usu-
ally located  on  the  face  or  neck,  and  are  commonly  congenital,  hence  the
terms  birik  mark,  mother's  mark.  A  nevus  may  remain  unchanged,  may
disappear,  or  it  may  rapidly  increase  in  size.  Violent  hemorrhage  results
from  injury  or  ulceration.
