“Reactive” implies benign etiology

Acute or chronic; any H&N nodal group

Response to infection/inflammation

Enlarged oval-shaped lymph nodes

± enlargement of lingual, faucial, or adenoidal hypertrophy

± stranding of adjacent fat (cellulitis)

± edema in adjacent muscles (myositis)

± suppurative nodes or abscess

Variable enhancement, usually mild

B-cell origin; histology shows Reed-Sternberg cells

Cervical & mediastinal nodes common

Waldeyer ring or extranodal < 1%

Tumors EBV positive in up to 50%

Cannot distinguish Hodgkin from non-Hodgkin lymphoma

Homogeneous lobulated nodal masses

Single or multiple nodal chain

Variable contrast enhancement

Necrotic center may be present

True vascular neoplasm

Usually not present at birth; typically presents in 1st few months of life

Rapid growth and spontaneous involution typical

Solid, avidly enhancing mass

Intralesional high-flow vessels

Fatty infiltration during involution

PHACES syndrome: Posterior fossa abnormalities, hemangiomas, arterial abnormalities, cardiovascular defects, eye abnormalities, sternal clefts

Carotid space, perivertebral space (brachial plexus) common

Localized, diffuse, or plexiform

Single or multiple

Localized: Well-circumscribed, smooth, solid masses with variable enhancement

Diffuse: Plaque-like thickening of skin with poorly defined linear branching lesion in subcutaneous fat

Plexiform: Lobulated, tortuous, rope-like expansion in major nerve distribution; “tangle of worms” appearance

All nodal chains involved

30% extranodal: Lymphatic (palatine or lingual tonsil and adenoids) or extralymphatic (paranasal sinuses, skull base, and thyroid)

Cannot distinguish non-Hodgkin from Hodgkin lymphoma

Single dominant node or multiple nonnecrotic enlarged nodes

Homogeneous fat density (CT) or signal (MR) without significant enhancement

If enhancement, suspect liposarcoma

Most cervical disease is metastatic

Large lymph nodes, rarely necrotic

Bilateral skull base metastasis common

Enhancing masses with aggressive osseous erosion and intracranial/intraorbital extension

Nodal spread common in papillary, distant spread common in follicular

3x more common in women

Usually 3rd & 4th decade, occasionally in adolescents, rare in young children

Variable: Small to large, “reactive” in appearance or heterogeneous, hemorrhagic, or cystic necrosis

Focal calcifications and solid foci of enhancement may be present

Calcifying epithelioma of Malherbe

Usually benign in children

Enhancing mass in subcutaneous fat

Variable calcification, adherent to skin

< 5% of neuroblastomas are primary cervical lesions

Range from immature neuroblastoma to mature, benign ganglioneuroma

Well-defined solid mass closely associated with carotid sheath

Intraspinal extension rare

Calcifications may be present

Unknown primary SCCa rare in children

Nasopharyngeal carcinoma with adenopathy may occur in teenagers

Enlarged, round nodes

May be heterogeneous ± multiple confluent nodes

Most common location in H&N is parameningeal (middle ear, paranasal sinus, nasopharynx)

Intracranial extension in up to 55% of parameningeal lesions