頸部腫塊

病因分三類:
    Congenital 
       -Branchial cleft cyst,
       -thyroglossal duct cyst,  
       -vascular anormalies(vascular tumor, vascular malformation)
       -laryngocele (喉囊腫)
       -ranula (舌下囊腫)(a mucocele or retention cyst arising from an obstruction in the sublingual glands in the floor of mouth)
       -teratoma
       -dermoid cyst
       -thymic cyst
        
     Inflammatory neck mass:
        Infectious:
          -reactive viral lymphadenopathy (頸部LAD最常見) [URI (adeno-, rino-, entero-); IM (EBV)]
          -bacterial lymphadenopathy
          -paracytic lymphadenopathy
        Non-infectious: (*considered, esp when symptoms and signs involve areas other than head and neck)
          -sarcoidosis,
          -Castleman disease,
          -Rosai-Dorfman disease,
          -Kawasaki disease.
   
    Neoplastic:
        -metastatic head and neck carcinoma
        -thyroid masses
        -salivary gland neoplasm
        -paragangliomas
        -Schwannoma
        -Lymphoma
        -Lipoma, & benign skin cyst

頸部解剖 & 淋巴回流區:

  頸部解剖 
    -中間
    -側面 (前, 後)

 淋巴結分布及回流區域的定位有助於當懷疑有癌症轉移時的找尋

當左右supraclavicular LN腫起, lesion 可能在 thorax
當左    supraclavicular LN腫起, lesion 可能在 腹部 (Virchow's node)。

病因:
淋巴結,
parotid masses,
thyroid lesions,
Vascular anomalies (vascular tumors and vascular malformations)
先天性:
  -Branchial cleft cyst,  
  -Ectopic nonmalignant cervical thyroid tissue
      (1) midline elements including an ectopic thyroid gland and TGDC remnants and 
      (2) lateral elements including 
             -true embryologic rests, 
             -paracytic nodules and 
             -exophytic nodules ("lateral aberrant thyroid") 
  -Laryngocele — A laryngocele is a herniation of the saccule of the larynx.


  -Thyroglossal duct cyst (TGDC), thyroid ectopia, Lingual thyroid,


*頸部最常見的先天囊腫: Thyroglossal duct cyst
*有 TGDC 常有 ectopic thyroid glands.
*Midline mass 合併有甲狀腺低下, 增加ectopic thyroid可能。  
*Lingual thyroid:
   The entire thyroid gland can fail to descend to its normal adult orthotopic site. 
   If the descent is completely arrested at the level of the base of tongue, a lingual thyroid results. Partial descent can result in an ectopic gland in a sublingual or prelaryngeal position.   
   Excessive migration can result in a substernal ectopic gland.

Among ectopic thyroid glands, 90 percent are lingual and 10 percent occur in other sites [21].

Thyroglossal duct remnant
(1) intralingual - 2 %, (2) suprahyoid - 24 %, (3) thyrohyoid - 61 %, (4) suprasternal - 13 %