First, I know..it's kind of frustrating to not have the actual diagnosis, but at the same time is a challenging excercise because one has to search almost all variables in a pathological entity in order to conclude in a definite diagnosis. Therefore, every possibility is valid in first instance. Now let's take a quick review..
The mass has a suprasellar origin, with a regular outlined border and almost entirely cystic component, has a blood-fluid level inside with a peripheral rim calcification.
Ok differentials regarding a suprasellar mass are contained in the acronym SATCHMO wich is a mnemonic wich stands for:
S: sarcoid, sellar tumour (pituitary adenoma)
A : aneurysm
T : teratoma
C : craniopharyngioma, cleft cyst (Rathke) , chordoma
H : hypotalamic glioma, hamartoma of tuber cinereum, hystiocitosis
M : meningioma, mets
O : optic nerve glioma
Some prefer adding an E at the end and moving 'histiocytosis' to this last letter as
E : eosinophilic granuloma
Over all, we have to choose those with cystic (or almost cystic) component and with the clinical presentation here are the most likely --> pituitary adenoma (macroadenoma and pituitary apoplexy), aneurysm, craniopharyngioma, rathke's cleft cyst.
1) Pituitary Macroadenoma
Pituitary macrocadenomas are the most common suprasellar mass in adults, and responsible for the majority of transsphenoidal hypophysectomies. They are defined a as pituitary adenomas greater than 10mm in size and are approximately twice as common as microadenomas.
Patients typically present with symptoms of local mass effect on adjacent structures (especially optic chiasm). Some may present hormal imbalance, with symptoms of hypopituitarism (from compression) or secretion. Hormonal imbalance due to overproduction tends to present earlier and tumours are thus usually small at presentation.
CT
No contrast attenuation can vary depending on haemorrhagic, cystic and necrotic components. Adenomas which are solid, without haemorrhage, typically have attenuation similar to brain (30-40HU) and demonstrates moderate contrast enhancement; less marked than one typically sees in meningiomas. Calcification is rare.
1.1) Pituitary apoplexy
Is the sudden enlargement of a pituitary adenoma, is difficult to diagnose. Sudden infarction, necrosis, or hemorrhage into a pituitary adenoma may be threatening to both vision and life if not treated promptly. Is characterized by the abrupt appearance of severe headache, nausea and vomiting, stiff neck, agitation, mental changes, visual loss and/or diplopia.
Click image to enlarge
2) Craniopharyngioma
A craniopharyngioma is a type of relatively benign (WHO grade I) neoplasm which typically arises in the sellar / suprasellar region. They account for ~ 1 - 5 % primary brain tumours. Craniopharyngiomas are typically very slow growing tumors. They arise from the cells along the pituitary stalk. They are classified by histology as benign; however, as with many brain tumors, their treatment can be difficult, and significant morbidities are associated with both the tumor and treatment.
There is a bimodal distribution, with the first peak between the ages of 10 - 14 years and a second peak in the 5th to 7th decades. There appears to be a similar incidence in both males and females.
There are two main (quite different) pathological types :
This type is seen predominantly in children. It consists of reticular epithelial cells which have appearances reminiscent of the enamel pulp of developing teeth.
There may be single or multiple cysts filled with thick oily fluid high in protein, blood products, and/or cholesterol, creating the so called "machinery oil". "Wet keratin nodules" are a characteristic histological feature. Calcification is usually present : ~ 90%.
On imaging a Rathke’s cleft cyst is seen as a well defined non enhancing midline cyst within the sella arising between the anterior and intermediate lobes of the pituitary. 40% are purely intrasellar and 60% have suprasellar extension. Purely suprasellar location, although reported, is rare.
Post contrast : Typically non enhancing although the cyst wall may enhance in some cases.
Click image to enlarge 
Aneurysm and Cystic Astrocytoma was originaly thought also but as we peer reviewed them was discharched for lack of clinical and imaging foundation.
So to conlude now we have a 75% confident that is a Rathke Cleft Cyst. The only thing that doesn't favor is the calcified rim wich is unusual. Craniopharyngioma is infrecuent as a cystic component (adamantinomatous) on adulthood but I presented a case of a 39 y/o with cystic characteristics, so that's why has to be on the differential.
Thank's to all who participated in the discussion, specially Dr. Wael Nemattalla, Dr. Imran Jindani, Dr. Lijesh Kumar, Dr. Anhuba Pandey (who reminded me to take in consideration Rathke's), Dr. Naweed Ashraf, Dr. Samuel Inbaraja.
A craniopharyngioma is a type of relatively benign (WHO grade I) neoplasm which typically arises in the sellar / suprasellar region. They account for ~ 1 - 5 % primary brain tumours. Craniopharyngiomas are typically very slow growing tumors. They arise from the cells along the pituitary stalk. They are classified by histology as benign; however, as with many brain tumors, their treatment can be difficult, and significant morbidities are associated with both the tumor and treatment.
There is a bimodal distribution, with the first peak between the ages of 10 - 14 years and a second peak in the 5th to 7th decades. There appears to be a similar incidence in both males and females.
There are two main (quite different) pathological types :
- adamantinomatous (paediatric)
- papillary (adult)
This type is seen predominantly in children. It consists of reticular epithelial cells which have appearances reminiscent of the enamel pulp of developing teeth.
There may be single or multiple cysts filled with thick oily fluid high in protein, blood products, and/or cholesterol, creating the so called "machinery oil". "Wet keratin nodules" are a characteristic histological feature. Calcification is usually present : ~ 90%.
Papillary
The papillary sub type is seen in adults and is formed of masses of metaplastic squamous cells. "Wet keratin" is absent. Cysts do form, but these are less of a feature, and the tumour is more solid. Calcification is uncommon.
CT
Typically seen as a heterogeneous mass in the suprasellar region. Calcification (except for the papillary type) and cysts are very common:
Calcification
overall 80 - 87% of craniopharyngiomas are calcified, they occur in a stippled pattern
adamantinomatous : 90%
papillary : rare 4
Cysts : Seen in 70 - 75% of cases (more frequently in the adamantinomatous type)
The papillary sub type is seen in adults and is formed of masses of metaplastic squamous cells. "Wet keratin" is absent. Cysts do form, but these are less of a feature, and the tumour is more solid. Calcification is uncommon.
CT
Typically seen as a heterogeneous mass in the suprasellar region. Calcification (except for the papillary type) and cysts are very common:
Calcification
overall 80 - 87% of craniopharyngiomas are calcified, they occur in a stippled pattern
adamantinomatous : 90%
papillary : rare 4
Cysts : Seen in 70 - 75% of cases (more frequently in the adamantinomatous type)
Click image to enlarge
3) Rathke Celft Cyst
Rathke’s cleft cysts are derived from or are remnants of Rathke’s pouch. Sellar and juxtasellar epithelial cysts comprise a spectrum of lesions that range from craniopharyngioma (aggressive and complex) to Rathke’s cleft cyst (simple and indolent).Intra- and suprasellar in location, Rathke’s cleft cysts have welldefined margins and midline location. The thin walls are lined by a single layer of epithelium. Mucin-secreting goblet cells may be present. Depending on the activity of the goblet cells and the rate of epithelial desquamation, the material within the cyst ranges from serous to mucoid. This variation in content is reflected on CT, where the attenuation is low (serous) to intermediate (mucoid).
On imaging a Rathke’s cleft cyst is seen as a well defined non enhancing midline cyst within the sella arising between the anterior and intermediate lobes of the pituitary. 40% are purely intrasellar and 60% have suprasellar extension. Purely suprasellar location, although reported, is rare.
CT
Non contrast : it is typically non-calcified and of homogenous low attenuation. Uncommonly it may be of mixed iso- and low attenuation, or contain small curvilinear calcifications in the wall (seen in 10 - 15% of cases)Post contrast : Typically non enhancing although the cyst wall may enhance in some cases.
So to conlude now we have a 75% confident that is a Rathke Cleft Cyst. The only thing that doesn't favor is the calcified rim wich is unusual. Craniopharyngioma is infrecuent as a cystic component (adamantinomatous) on adulthood but I presented a case of a 39 y/o with cystic characteristics, so that's why has to be on the differential.
Thank's to all who participated in the discussion, specially Dr. Wael Nemattalla, Dr. Imran Jindani, Dr. Lijesh Kumar, Dr. Anhuba Pandey (who reminded me to take in consideration Rathke's), Dr. Naweed Ashraf, Dr. Samuel Inbaraja.
No hay comentarios:
Publicar un comentario