Glomus tumor is a rare benign tumor of the glomus body that was first described surgically by Wood in 1812.
In pathologic terms,
this tumor is a hamartoma that develops from the neuromyoarterial glomus body,
which was originally described by Masson and Popoff.
The glomus body is a highly specialized arteriovenous anastomosis that is responsible for thermoregulation.
Glomus bodies consist of an afferent arteriole,
a tortuous arteriovenous anastomosis,a system of collecting veins,
and a neurovascular reticulum that regulates the flow of blood through the anastomosis.
Glomus bodies are present in the stratum reticularis of the dermis throughout the body,
but they are highly concentrated in the digits,
palms,
and soles of the feet.
location:
75% occur in hand
50% are subungual
50% have erosions of distal phalanx (primary involvement of bone being very rare)
less common locations: palm,
wrist,
forearm,
foot
Glomus tumours have previously been classified into solitary,
multiple and congenital,
or histologically by the prevailing cell type into glomus tumours (predominant cell – glomus cells),
glomangiomas (blood vessels) and glomangio myomas (smooth muscle cells).
However,
glomangiomas are now probably best considered as a subtype of venous malformation,
rather than as a tumour.
Glomus tumours are typically a solitary,
painful 1-2 cm reddish blue papule or nodule found on a young adult.
They most commonly affect the nail bed or the palm.
They are usually tender to touch,
but may be extremely painful,
particularly following change in temperature or pressure.
Extracutaneous glomus tumours have been reported rarely in the gastrointestinal tract,
mediastinum,
trachea,
mesentery,
cervix and vagina.
Under the microscope (histologically),
there are solid sheets of glomus cells around small blood vessels.
Immuno histochemical studies may be helpful in diagnosis
Glomangiomas,
on the other hand,
are less common glomuvenous malformations,
and are typically found in infancy or childhood.
They have been reported at birth (congenital),
although rarely.
They are usually multiple,
soft,
red-to-blue nodules but may appear as pink to deep blue plaque-like lesions.
They are often widespread,
and can join together to become larger plaque