SKYPE

A

MEDIAL SUPERFICIAL

B

LATERAL SUPERFICIAL

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Oc c i p i t a l N o d e s

The o c c i p i t a l nodes consist of two subgroups: the

super f i c i a l and the deep nodes. The s uperficial nodes usually n u m b e r one or two. They are flat and vary from 0.5 to 1.0 cm in size. T hey are most commonly found b e t w e e n the superficial cervical fascia a n d the splenius muscle, lying b e t ween the

i n s e r t i o n s of the sternomastoid and trapezius muscles at the a p e x of the p o s t e r i o r triangle. They r e c e i v e lymph from the o c c i p i t a l area of the scalp and skin of the upper part of the b a c k of the neck. Their efferent d rainage goes either to the de e p occipital, or to the deep upper spinal acce s s o r y nodes.

There is o n l y u s u a l l y one deep o c cipital node. A

c o n s i s t e n t f i n d i n g is that the node is elongated, measuring up to 0.5 x 0.2 x 0.2 cm. It lies b e l o w the splenius capitis muscle, r e c e i v e s lymph from the superficial occipital nodes and d r ains into the deep spinal a c cessory nodes.

P o s t a u r i c u l a r Nodes

The p o s t a u r i c u l a r nodes may number 1 to 4, although 1 is the most c o m m o n number. They are more p r e v a l e n t in the y o u n g and are o f t e n atrophic or absent in the elderly

(Feind, 1972) . T h e single postauricular node is a flat oval n o d e m e a s u r i n g 0.5 to 0.7 cm or smaller. It is situated

The p o s t a u r i c u l a r nodes are often non-existent, b e i n g absent in one third of foetuses and half the adult and a ged

(Rouviere, 1932) . Their afferent vessels o r i g i n a t e from the post e r i o r p o r t i o n of the parietal and m a s t o i d r e g ions of the scalp, t ogether w i t h the skin over the p o s t e r i o r a s p e c t of the auricle. E f f e r e n t vessels pass either to the infra-

a u ricular p a r otid nodes or to the junctional d eep cerv i c a l nodes.

P a r o t i d Nodes

R o u v i e r e d i v i d e d the p a r otid nodes into e x t r a g l a n d u l a r (or periglandular) and i n t r aglandular (Rouviere, 1932) . The e x t r a g l a n d u l a r g r oup is subdivided into the p r e a u r i c u l a r and i n f r a - a u r i c u l a r nodes. T h ese nodes are c o n t a i n e d in the p a r o t i d sheath or are a d j a c e n t to the p a r o t i d g l a n d w i t h the sheath b l e n d i n g in w i t h the node capsule. The p r e a u r i c u l a r group lies over the superficial aspect of the p a r o t i d gland. There may be 1 to 4 nodes (0.1-0.5 cm in size) in the

p r etragal area, and these are the most s u p e rficial nodes. The r e m a i n i n g nodes, w h e n present, become p a r t of the

intra g l a n d u l a r division. The i n f r a-auricular nodes c o n s i s t of 1-4 nodes. They lie a d j a c e n t to the p o s t e r i o r facial v ein at the lower pole of the p a r o t i d gland. The p r e a u r i c u l a r nodes r e c e i v e affe r e n t v e s s e l s from the lateral and frontal a spects of the scalp and f r o m the cranial vault. T h e y also r ece i v e vessels from the auricle, external a u d i t o r y canal, the lateral half of the lower eyelid, the u p p e r e y e l i d and the root of the nose. The infr a - a u r i c u l a r group r e c e i v e s v e s s e l s

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from the cheek, b u c c a l mucosa, parotid gland, nose and

upper eyel i d (Feind, 1972). There has been some c o n t r o v e r s y about the actual numb e r of lymph nodes w h i c h occur w i t h i n the p a r o t i d gland. R o u v i e r e numbers the intragla n d u l a r nodes 4-10 w ith a m a x i m u m of 14. This has been c o n f i r m e d by others

(Graham, 19 65; Marks, 1984), but others have q u o t e d three times this figure (Conley and Arena, 1963; Pope and Lehman, 1967). F eind found an a v e r a g e of 20 nodes (Feind, 1972) and it is his work, t o g e t h e r w i t h Rouviere's, that is f r e q u e n t l y quoted by others. T h e intragla n d u l a r nodes are found embedded w i t h i n the parotid, a n d lie chiefly in the superficial portion of the g l a n d a l o n g s i d e the posterior facial vein. They

receive a f f e r e n t v e s s e l s from the parotid gland, the skin of the side of the head a bove the parotid gland, the lateral aspect of the eyelids, the c o n j u nctiva, the external a u d i t o r y meatus, the E u s t a c h i a n tube a n d tympanic membrane. They also receive e fferent trunks from the extraglandular p a r o t i d nodes. Both the i n t r a g l a n d u l a r a n d e x t r a g l a n d u l a r lymph nodes should be r egarded as a c o m p l e t e e n t i t y as they function as one unit

(Feind, 1972). E f f e r e n t vessels from the p a r o t i d nodes pass from the p r e a u r i c u l a r e x t r a g l a n d u l a r nodes to b oth the

intragla n d u l a r and i n f r a - a u r i c u l a r nodes, and then on to the upper deep lateral c e r v i c a l nodes.

S u b m a n d i b u l a r

T h e r e are p revascular and p o s t v a s c u l a r , preglandular, r e t r o g l a n d u l a r and intracapsular s u b m a n d i b u l a r nodes

(Rouviere, 1932; Feind, 1972). The prevascular group consists only u s u a l l y of one node (0.4-0.7 c m in size) which sits

in f r o n t of the anterior facial v e i n on the facial artery, and w h i c h is in c o n tact with the m a n d i b u l a r branch of the facial nerve. The p o s t vascular g r o u p may be made up of one

or two nodes s ituated along the edge of the anterior facial vein. The p r e g l a n d u l a r g r oup consists of one or two nodes in front

of the s u b m a n d i b u l a r gland, superficial to the mylohyoid muscle, w h i c h m e a sure 0.2-0.5 cm in size and which are

i n t i m a t e l y r e l a t e d to the submental vein. The retroglandular node is a rare finding w h i c h has b e e n found in surgical

s p e c i m e n s b u t not injected cadaver specimens. It is probably a d e e p l y situ a t e d postvascular node or a laterally placed

" subl i n g u a l " node (Feind, 1972) . The intracapsular submandibular no d e s p r o b a b l y do not exist. Feind stated that he had not

seen a lymph g l a n d completely e n g u l f e d by the submandibular s a l i v a r y g land a l t h o u g h he had seen a node protrude from, or be p a r t i a l l y e m b e d d e d in, an interlobar fissure on the deep side of the gland. He concluded these nodes should be included as the r e t r o g l a n d u l a r group and the i n tracapsular group be

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nodes take origin from the e f f e r e n t vessels of the submental nodes and the facial node. The f o llowing are considered sources of lymphatic drainage: s u b m a n d i b u l a r salivary gland, lower

and upper lip, cheeks, nose, nasal fossae mucosa, gums, teeth, medial parts of eyelids, p o s t e r i o r palatine fossae, anterior faucial pillar, soft palate and m a n y of the collecting vessels of the anterior two thirds of the tongue. E fferent pathways h a v e been described to the u p per deep lateral cervical nodes (Rouviere, 1932; Feind, 1972) , lower internal jugular nodes (Rouviere, 1932), and to the spinal accessory nodes

( S a s s i e r , 1927).

Facial Nodes

R o u v i e r e divided the facial nodes into four main groups: bu c c inator, infraorbital , m alar and inferior maxillary

(Rouviere, 1932). To avoid c o n f u s i o n between maxillary and mandibular, the inferior m a x i l l a r y group has been renamed m a n d i b u l a r (Feind, 1972). T h e r e is only usually one

m a n d i b u l a r facial node (the node of S t a h r ) , but occasionally t h ere may be three. It is the m o s t constant facial node and its usual position is over the mandible, in front of the

facial vessels, superficial to the insertion of the b u c cinator musc l e on the mandible. The m a n d i b u l a r facial nodes are

located on the collecting lymphatics from the medial part of the eyelids, the medial orbit, the nose, the nasolabial

fold, the upper lip, cheek and anterior part of the zygomatic region. The b u c cinator group is o f ten absent. They lie

s u p e r f i c i a l to the buccinator muscle b e l o w the line of

S t e n s o n ' s duct, and lie along the lymphatic v e s sels heading for the mandi b u l a r facial nodes. The infraorbital node is r a r e l y p r e sent (Feind, 1972). It can be anywhere along the n a s o l a b i a l fold from the inner canthus to the alar, and it is situ a t e d on the afferent lymphatic vessels d r a i n i n g this area. The malar node has only b e e n reported twice

(Watzold, 1927; Rouviere, 1932). It was found just b e l o w the o uter canthus on the lymphatic path w a y d raining the upper

lid (Feind, 1972). All the facial nodes d rain into the s u b m a n d i b u l a r group of nodes.

Submental Nodes

There has been much d i s c r e p a n c y in the d e s c r i p t i o n s of the submental lymph nodes (Stahr, 1898 p 444; P o i r i e r and

Cuneo, 1903; Sassier, 1927; Rouviere, 1932). R o u v i e r e divided the submental nodes into three groups: anterior, middle

and p o s t e r i o r and further d i v ided the middle g r o u p into

m e dial and lateral. These nodes may number 2 to 8, the average b e i n g a bout 5. They vary in size from 0.2-0.6 c m and lie in the a d i pose tissue of the submental triangle. The nodes r e c e i v e superficial lymphatics from the chin, m i d d l e of the

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lower lip and the cheeks. The deeper afferent path w a y s drain the gums, a n t e r i o r floor of the mouth and anterior t h i r d of the tongue. The nodes themselves are interconnected and give

e f f e r e n t path w a y s to ipsilateral or c o ntralateral neck nodes. T h e s e e f f e r e n t p a t h w a y s go to either the subma n d i b u l a r nodes or to the upper d e e p lateral cervical nodes via v e s sels which a c c o m p a n y the v e n a e comitans nervi hypoglossi (Feind, 1972).

Sublingual N o d e s

A l t h o u g h R o u v i e r e included these nodes w i t h i n his

c l a s s i f i c a t i o n , s u b s e q u e n t workers have failed to d e m o n s t r a t e their p r e s e n c e in clinical specimens (Feind, 1972). They c o n s i s t of i n t e r r u p t i n g nodules along the c o l l e c t i n g trunks of the tongue and sublingual salivary gland. They proba b l y should not be g r o u p e d as head and neck nodes (Feind, 1972) , and are not d i s c u s s e d further.

R e t r o p h a r y n g e a l Nodes

T h ese nodes lie b e h i n d the pharynx and in front of the p r e v e r t e b r a l fascia. M o s t and Rouviere r e p o r t e d t hem only to the level of t h e grea t e r cornu of the h yoid bone

(Most, 1900? Rouvi e r e , 1932), although others have shown they can occur f r o m the skull base to the t horacic inlet

The lateral g r o u p is invariably present in the infant, but a b s e n t in the adult. They are true nodes, and u s u a l l y three