Sellar/suprasellar mass

Question 1

Differential diagnoses for sellar/suprasellar mass in child

Answer 1

1. Craniopharyngioma
2. Germ cell tumor
3. Rathke Cleft Cyst
4. Optic nerve/hypothalamic glioma
5. Hypothalamic hamartoma

Question 2

Imaging features of craniopharyngioma

Answer 2

• most common suprasellar masses in children. They are benign
  tumors which arise from Rathke pouch epithelium.
• TWO subtypes, each with varying age peaks and imaging features: adamantinomatous (peak age: 5–15 years) and
  papillary (peak age: >50 years).
• Pediatric adamantinomatous
  craniopharyngiomas present as multicystic suprasellar masses which may extend into the sella, anterior and middle cranial fossae, and retroclival regions. CT
  demonstrates amorphous calcifications in more than 90% of cases. There is often sellar expansion and clival remodeling or erosion. Both CT and MRI reveal a mixed cystic and solid
  suprasellar mass with enhancement of the solid components and cyst walls. The cystic content may be hyperdense on CT,
  hyperintense on T1, and variable on T2 sequences due to increased
  protein content, which is described as “crank case oil”
  on gross pathologic examination.
• In contrast, the adult variant (papillary) most commonly presents as a solid enhancing
  suprasellar mass without calcifications.

Question 3

Imaging features of Germ Cell tumor

Answer 3

• Most common in the paediatric population
• Occurs most commonly in the pineal region, then followed by suprasellar region.
• Typically midline.
• Germinomas are most common subtype, presenting as infiltrating sellar and/or suprasellar masses which typically follow gray matter signal and homogeneously enhance. With
  sellar involvement, there is often absence of the posterior pituitary
  bright spot on precontrast T1 images.
• Teratomas are
  more heterogeneous and usually have regions of macroscopic fat and calcification.
• Dermoid cysts may follow cerebrospinal fluid (CSF) signal on T2-weighted sequences but are often
  slightly hyperintense to CSF on T1 and may have wall calcification. When present, fat–fluid levels are characteristic.
• GCTs
  may seed the CSF due to direct extension (germinomas) or
  rupture (dermoid cysts)

Question 4

Imaging features of Rathke Cleft Cyst

Answer 4

• Nonneoplastic lesions
  which arise from remnants of Rathke cleft.
• The lesions are often
  intrasellar; many will have suprasellar extension.
• Roughly 10 to 15% will
  have curvilinear wall calcification.
• MRI: the cystic fluid may have variable signal intensity
  based on mucinous content. Lesions with high mucin content will be hyperintense on T1 sequences.
• An intracystic nodule
  is commonly seen, which is a useful discriminator. There is no internal enhancement, but a rim of enhancing pituitary gland
  is often seen.

Question 5

Imaging features of optic nerve/hypothalamic glioma

Answer 5

• Optic nerve gliomas are
  low-grade tumors that often occur between 5 and 15 years of age. They may be sporadic or associated with NF-1; bilateral
  optic nerve gliomas are pathognomonic for NF-1.
• Tumors cause enlargement, elongation, and “buckling” of the optic nerve.
• Enhancement is variable. The tumor may extend along
  the optic pathway. Non-NF-1 cases tend to involve the optic chiasm and/or hypothalamus, are typically larger and more
  masslike, commonly have cystic degeneration, and often extend beyond the optic pathways.
• Hypothalamic gliomas are
  similar in appearance but centered in the hypothalamus.

Question 6

Imaging features of hypothalamic hamartomas

Answer 6

benign lesions that occur in children with gelastic seizures or
precocious puberty.

The hamartomas are isointense to gray
matter on T1 and iso- to hyperintense on T2 sequences. No
enhancement should be seen; the presence of enhancement
suggests a hypothalamic glioma rather than hamartoma. Clinical
features combined with imaging findings are key to making the diagnosis.

Question 7

e differentials for pituitary region masses (in addition to macroadenoma)

Answer 7

SATCHMO/STOMACH
S: sarcoid
A: aneurysm
T: teratoma or tuberculosis (and other granulomatous diseases)
C: craniopharyngioma, cleft cyst (Rathke), chordoma
H: hypothalamic glioma, hamartoma of tuber cinereum, histiocytosis
M: meningioma, metastasis
O: optic nerve glioma

Some prefer adding an E at the end and moving ‘histiocytosis’ to this last letter as:
E: eosinophilic granuloma or epidermoid/dermoid/teratoma

Question 7

What are the differentials for pituitary region masses (in addition to macroadenoma)? SATCHMO

Answer 7

SATCHMO/STOMACH
S: sarcoid
A: aneurysm
T: teratoma or tuberculosis (and other granulomatous diseases)
C: craniopharyngioma, cleft cyst (Rathke), chordoma
H: hypothalamic glioma, hamartoma of tuber cinereum, histiocytosis
M: meningioma, metastasis
O: optic nerve glioma

Some prefer adding an E at the end and moving ‘histiocytosis’ to this last letter as:
E: eosinophilic granuloma or epidermoid/dermoid/teratoma