igin in the scalp, ear, or throat.

If operative interference is called for, the cysts may be tapped and
injected with iodine, or excised; the operation for removal may entail a
considerable dissection amongst the deeper structures at the root of the
neck, and should not be lightly undertaken; parts left behind may be
induced to cicatrise by inserting a tube of radium and leaving it for a
few days.

Lymphangiomas are met with in the abdomen in the form of _omental
cysts_.

DISEASES OF LYMPH GLANDS

#Lymphadenitis.#--Inflammation of lymph glands results from the advent
of an irritant, usually bacterial or toxic, brought to the glands by the
afferent lymph vessels. These vessels may share in the inflammation and
be the seat of lymphangitis, or they may show no evidence of the passage
of the noxa. It is exceptional for the irritant to reach the gland
through the blood-stream.

A strain or other form of trauma is sometimes blamed for the onset of
lymphadenitis, especially in the glands of the groin (bubo), but it is
usually possible to discover some source of pyogenic infection which is
responsible for the mischief, or to obtain a history of some antecedent
infection such as gonorrhoea. It is possible for gonococci to lie latent
in the inguinal glands for long periods, and only give rise to
lymphadenitis if the glands be subsequently subjected to injury. The
glands most frequently affected are those in the neck, axilla, and
groin.

The characters of the lymphadenitis vary with the nature of the
irritant. Sometimes it is mild and evanescent, as in the glandular
enlargement in the neck which attends tonsillitis and other forms of
sore throat. Sometimes it is more persistent, as in the enlargement
that is associated with adenoids, hypertrophied tonsils, carious teeth,
eczema of the scalp, and otorrhoea; and it is possible that this indolent
enlargement predisposes to tuberculous infection. A similar enlargement
is met with in the axilla in cases of chronic interstitial mastitis, and
in the groin as a result of chronic irritation about the external
genitals, such as balanitis.

Sometimes the lymphadenitis is of an acute character, and the tendency
is towards the formation of an abscess. This is illustrated in the
axillary glands as a result of infected wounds of the fingers; in the
femoral glands in infected wounds or purulent blisters on the foot; in
the inguinal glands in gonorrhoea and soft sore; and in the cervic