Brain sellar

Question 1

DD CYSTIC lesions in the sella

Answer 1

-Empty sella

-Intracranial hypertension: usually female obese. Papilledema. Intraoptic protrusion of optic nerve head, enlarged optic nerve sheaths, ventricle slit like, narrowed subarachnoid, cistern and surface sulci.

-Cystic pituitary adenoma.

-Arachnoid cyst: bony sella might be expanded.

-Pituitary apoplexy

-Epidermoid cyst: usually extension from cerebellopontine angle.

-Rathke cleft cyst: 75% have intracystic nodule + claw sign of surrounding pituitary gland.

-Craniopharyngioma: rare. Ca+ Cyst. 90% rule for adamantinomatous: 90% Ca+, 90% cystic, 90% enhances.
-Epidermoid: restricted diffusion, T2 hyper.

-Pars intermedia cyst: bening cyst in between adenhypophysis and neurohypophysis.

-Saccular aneurysm.

Question 2

DD sellar mass

Answer 2

-Adenoma

-Rathke’s cleft cyst: no enhancement.

-Craniopharyngioma: Ca+ and cystic common. Usually present larger. Adamantinomatous cranipharingiomas are most frequent in children.

-Mets: rare.

-Pituitary hyperplasia.

-Pituitary carcinoma: indistinguishable. May have CSF seeding.

-Infection/abscess: as complication of sinus inflammatory disease

-Aneurysm, medial from cavernous ICA

-Meningioma: rare. Vivid enhancement.

-Hypophysitis (lymphocytic or granulomatous)

-Sarcoidosis.

-Lymphoma

-CNS siderosis

Question 3

Hypophysitis,
pathological classification?

Answer 3

Lymphocitic
More frequently: peripartum women w/headache and visual disturbance.
much less common: Old man w/end organ insufficiency.
Autoimmune, inflammatory, idiopathic.
Most cases self limiting. Could be fatal.

Granulomatous
TB, syphilis, sarcoid, Wegner

Plasmocytic
IgG4 related

Question 4

Hypophysitis,
Dx

Answer 4

-Thick stalk (> 2 mm + loss of normal “top to bottom” tapering)

± enlarged pituitary gland

75% show loss of posterior pituitary “bright spot”

Enhances intensely, uniformly

May have adjacent dural or sphenoid sinus mucosal thickening

Question 5

Pituitary hyperplasia,
Causes

Answer 5

Physiological - pregnancy related

Pathologica: end organ insufficiency related, neuroendocrine tumor:

-Growth hormone cell hyperplasia occurs with neuroendocrine tumors
Pancreatic islet cell tumor, pheochromocytoma, and bronchial and thyroid carcinoid tumors
Associated with McCune-Albright syndrome, multiple endocrine neoplasia syndrome, and Carney complex

-Prolactin cell hyperplasia:
May be seen with pregnancy and lactation, estrogen treatment, primary hypothyroidism, Cushing disease

-Corticotroph hyperplasia
Associated with Cushing disease, neuroendocrine tumors, untreated Addison disease

-Thyrotroph hyperplasia
Longstanding primary hypothyroidism, may have associated prolactin hyperplasia

-Gonadotroph hyperplasia (e.g., Turner, Klinefelter syndromes)

Question 6

Pituitary hyperplasia,
Dx.

Answer 6

enlarged homogenously enhancing pituitary gland w/convex superior margin.

Question 7

Rathke Cleft cyst,
Definition

Answer 7

Congenital. Benign cyst arising from remnant of embryonic rathke cleft (non-regression)

Question 8

Rathke Cleft cyst,
Dx

Answer 8

Nonenhancing, noncalcified, intrasellar &/or suprasellar cyst with** nonenhancing intracystic nodule**

Usually completely intrasellar (40%), suprasellar extension (60%)

Density/signal intensity varies with cyst content (serous vs. mucoid most commonly)

Ca+ rare, 10-15%

No internal enhancement

Most symptomatic RCCs: 5-15 mm in diameter; Occasionally RCCs can become very large

Claw sign = enhancing rim of compressed pituitary surrounding nonenhancing cyst

Question 9

type of wall cell? internal content?

Rathke Cleft cyst,
Path

Answer 9

-wall: **single layer of ciliated cuboidal/columnar epithelium +/- globet cells. **

-May have squamous metaplasi
recurrencea = increase squamous metaplasi
recurrence .

-Variable cyst content: most frecuently mucoid, also clear, serous, haemorrhage, hemosiderin, etc.

Question 10

Diabetes insipidus
Definition?

Answer 10

Def: ADH (anti diuretic hormone) deficiency or resistance which results in polyuria and polydipsia,
Path:

Question 12

Diabetes insipidus,
Causes

Answer 12

-Central/neurogenic/hypothalamic: ADH deficiency, reduced production(more common). Anomaly of the pituitary gland/hypothalamus can be seen: tumor, inflammation, infection, etc.
Trauma, neurosurgery
Malignancy, e.g. craniopharyngioma, germinoma, metastases
Autoimmune disease, e.g. lymphocytic hypophysitis
Inflammatory disease, e.g. sarcoidosis, Langerhans cell histiocytosis, IgG4-related
Infection, e.g. tuberculosis
Other: pregnancy
Familial (rare)
Idiopathic

-Peripheral/Nephrogenic: Renal tubular unresponsiveness to ADH (vasopressin resistance)
Chronic kidney disease
Pregnancy
Long term lithium use (15%)
Metabolic: hypokalaemia, hypercalcaemia

Question 13

SIADH,
Definition

Answer 13

Inappropriate release of ADH - Excessive resorption of free water - dilutional hyponatremia, cerebral oedema.

Question 15

SIAD, causes

Answer 15

Malignancy:
SCLC (paraneoplastic syndrome), NSCLC, H&N tumor, lymphoma, Ewin, GI and GU.

**Lung disease: **
Infection: pneumonia, abscess, TB, aspergillosis,
Asthma,
CF

Drugs
Antidepressants, NSAIDs, antiepileptic,

CNS disorders: infection (meningitis, encephalitis), haemorrhage, miscellaneous, trauma