Thyroid Tumours - Approach

Classification:

1.Epithelial -

• Papillary
• Follicular
• Anaplastic (old patient, rapidly growing, no Rx, median survival 3-6/12)

2. "C" cells -

• Medullary (Sporadic, Familial, MEN II)

3. Others -

• Lymphoma
• Sarcoma
• Mets

* Well differentiated Thyroid CA:

Papillary

a. Standard

b. Solid variant (post irradiation)

c. Follicular variant


Follicular

a. Minimally invasive

b. Widely invasive


*Anaplastic

a. Squamoid variant

b. Small cell variant - can look like lymphoma, medullary Ca)



Poorly differentiated Ca

a. Tall cell

b. Insular cell

Invx & Mx

Careful hx paying attention to

1. Lump factors

2. Risk factors for Thyroid Ca (Radiation - occupational, Chernobyl, lymphoma RxT to thymus & FHx - medullary Ca)

3. Cx of Ca (RLN invasion, LN, SVC compression, retrosternal extension - stridor, fixity to str. - skin/strap muscles, haemoptysis, mets - lung, bone)

Biochemical assessment

• Thyroid functional status - Free T4 and TSH
• Thyroid Antibodies - anti-thyroglobulin and anti-microsomal
• If positive family history an possibility of medullary carcinoma - calcitonin
• If suspicion of MEN2 Syndrome will need 24 hr urinary catecholamine estimations to exclude phaeochromocytoma prior to surgery
  

Standard radiography
Chest radiography and thoracic inlet views if obstructive symptoms

Isotope scanning

• 131I , 123I or 99Tch scanning provides functional assessment of thyroid
• Nodules classified as cold, warm or hot
• Unable to differentiate benign and malignant nodules
• Most solitary thyroid nodules are cold
• Most cancers arise in cold nodules
• Risk of cancer in a cold nodule is 10-15%
• Risk of tumour in a hot nodule is negligible
• Scintigraphy of minimal use in evaluation of solitary thyroid nodules
• Useful in recurrent thyroid swellings and retrosternal goitres

Ultrasound

• Will define solitary and dominant nodules
• Will distinguish solid and cystic lesions
• Most sonographically solid lesions are benign
• Cancer can occur in the wall of a cystic lesion
• No reliable criteria to distinguish benign and malignant lesions
  

Fine needle aspiration cytology

• Should be first line investigation of the solitary thyroid nodule
• With experienced cytologist diagnostic accuracy can be >95%
• Possible cytopathological diagnoses are:
  Benign
  Malignant
  Indeterminate
  Inadequate
• Can distinguish benign and malignant tumours except follicular neoplasms
• Diagnosis of follicular carcinoma depends on the visualisation capsular
• If follicular neoplasm on FNA lesion will require surgical excision
• False negative rate less than 5% in most institutions
• Definitive FNA cytology allows:
  Non-operative treatment with benign disease
  Appropriate surgical treatment of thyroid cancers at initial operation
  Surgery can be avoided in anaplastic tumours and lymphomas
  Reduces total number of thyroid lobectomies
  Increases yield of thyroid cancers
• Brown fluid - thyroid cyst
• Thick brown fluid - MNG
• Scanty, bloody, cellular material - papillary/follicular
  

Indications for surgery after FNA cytology

• All proven malignant nodules
• All cytologically diagnosed follicular neoplasms
• All lesions exhibiting an atypical but non-diagnostic cellular pattern on cytology
• Cystic nodules which recur after aspiration
• When on clinical grounds the index of suspicion of malignancy is high even if the cytology report suggests it is benign

Facial Nerve Palsy

Facial Nerve

Anatomy
· Facial nerve arises at junction of pons and medulla
· Traverses the following structures
o Posterior cranial fossa
o Internal auditory meatus
o Temporal bone in the facial canal
o Stylomastoid foramen
o Parotid gland
· The terminal motor branches are:
o Temporal
o Zygomatic
o Buccal
o Marginal mandibular
o Cervical

Function
· Motor to the muscles of facial expression

· Parasympathetic secretomotor to the lacrimal gland
o via the greater petrosal nerve

· Parasympathetic secretomotor to the submandibular and sublingual salivary glands
o via the Chorda tympani

· Taste to the anterior two-thirds of the tongue
o via the Chorda tympani and lingual nerve

· Somatic sensory to an area of skin around the external auditory meatus
o via fibres from the geniculate ganglion

Facial nerve palsy
· Lower motor neurone affects whole of one side of face
· Upper motor neurone spares the forehead
· Bell's palsy accounts for 40% of facial nerve palsies
· Idiopathic and usually self-limiting
· May result from viral infection

Causes (Intracranial, Intratemporal, Infratemporal)

· Intracranial
o Brainstem lesions
o Cerebrovascular accident
o Multiple sclerosis
o Acoustic neuroma
o Cholesteatoma

· Intratemporal
o Otitis media
o Ramsay Hunt syndrome - herpes zoster oticus
o Trauma - temporal bone fracture
o Iatrogenic

· Infratemporal
o Parotid tumours
o Trauma
o Surgery

Management
· Protection of eye
· Tarsorrhaphy may be required if palsy persists
· Surgery
· Bell's palsy - steroids may be beneficial
· Ramsey Hunt syndrome - acyclovir

Breast Cancer: Imaging

Breast imaging

The breast can be imaged with
1) mammography
2) ultrasound
3) MRI
Mammography is the most sensitive of breast imaging modalities
Sensitivity is reduced in young women due to the presence of increased glandular tissue
For symptomatic patients, imaging always be performed as part of triple assessment

Mammography
Abnormalities detected on mammography are classified as:
1) Spiculated masses
2) Stellate lesions
3) Circumscribed masses
4) Microcalcification

Spiculated masses
Soft tissue mass with spicules extending into surrounding tissue
95% of spiculated masses are due to invasive cancer
Other causes of spiculated masses include:
Ductal carcinoma in-situ (DCIS)
Radial scar / complex sclerosing lesion
Fat necrosis
Fibromatosis
Granular cell myoblastoma

Stellate lesions
Localised distortion of the breast parenchyma with no perceptible mass lesion
Differential diagnosis of stellate lesions includes:
Radial scar
Invasive cancer
DCIS
Surgical scar

Circumscribed masses
Circumscribed masses should be analysed according to density, outline and size
Differential diagnosis of circumscribed masses includes:
Fibroadenoma
Cyst
Mucinous or medullary carcinoma
Lipoma
Abscess

Microcalcification
Microcalcification is due to debris within the duct wall or lumen
Sole feature of 33% of screen-detected cancers
Malignant microcalcification is usually linear or branching
Benign microcalcification is usually rounded and punctate
Differential diagnosis of microcalcification includes:
DCIS
Invasive cancer
Papilloma
Fibroadenoma
Fat necrosis

Breast ultrasound
Ultrasound is useful in the assessment of breast lumps
Complements mammography and is able to differentiate solid and cystic lesions
Also able to guide fine needle aspiration and core biopsies
Can be used to assess tumour size and response to therapy
In the diagnosis of malignancy it has a sensitivity and specificity of 75% and 97% respectively
Cysts and solid lesions have typical appearances

Cysts
On ultrasound examination cysts have:
1) Smooth walls
2) Sharp anterior and posterior borders
3) Black hypoechoic centres without internal echoes

Solid lesions
Solid lesions have internal echoes
Malignant tumours have:
1) Hypoechoic areas interspersed between brighter echoes
2) Irregular edges
3) Cast hypoechoic shadows
Benign tumours have:
1) Isoechoic or hypoechoic patterns
2) Smooth well defined borders
3) Cast no hypoechoic shadows