Case Of the Week (COW) 30 Mar 2014
Answer:
ENDOLYMPHATIC SAC TUMOUR LEFT
Findings:
Focal mildly expansile lytic lesion noted in the region of the left endolymphatic sac with central calcific spiculations. MRI of inner ear reveals a predominatly T2 hyperintense lesion showing heterogenous contrast enhancement. The above features are fairly typical of ENDOLYMPHATIC SAC TUMOR.
Discussion:
The endolymphatic sac is located at end of endolymphatic duct. The typical CT findings of endolymphatic sac tumors are: Lesions centered over the endolymphatic sac, retrolabyrinthine, and presigmoid regions of the temporal bone. Central calcific spiculation(intramural bone spicules) and posterior rim calcification is a characteristic feature seen in almost all cases. .T1-weighted MRI scans showed hyperintense foci . T1-weighted post-gadolinium scans showed heterogeneous enhancement . T2-weighted images showed heterogeneous signals . Angiography (traditional or magnetic resonance angiography [MRA]) exclusive external carotid supply for lesions less than 3 cm. Tumors greater than 3 cm were supplied by external carotid, internal carotid, and posterior fossa circulation arteries. Bilateral Endolymphatic sac tumors are pathognomonic of Von Hippel Lindau Disease. The lesion can be differentiated from 1.Cholesterol Granuloma (lesion centred over petrous apex ; smooth expansion with bony dehiscence ; Typical T1 hyperintensity and peripheral hypointense rim in T2W1) 2. Glomus Juglare –epicentre over Jugular foramen.
Ref: The Laryngoscope - Volume 116, Issue 1, pages 40–46,January 2006 The Radiologic Diagnosis of Endolymphatic Sac Tumors Nirmal P. Patel
Contributed By:
Dr. Babu Peter MD, DNB
Associate Professor, Barnard Institute of Radiology
Senior Consultant Radiologist, Aarthi Scans, Chennai
Answer:
ENDOLYMPHATIC SAC TUMOUR LEFT
Findings:
Focal mildly expansile lytic lesion noted in the region of the left endolymphatic sac with central calcific spiculations. MRI of inner ear reveals a predominatly T2 hyperintense lesion showing heterogenous contrast enhancement. The above features are fairly typical of ENDOLYMPHATIC SAC TUMOR.
Discussion:
The endolymphatic sac is located at end of endolymphatic duct. The typical CT findings of endolymphatic sac tumors are: Lesions centered over the endolymphatic sac, retrolabyrinthine, and presigmoid regions of the temporal bone. Central calcific spiculation(intramural bone spicules) and posterior rim calcification is a characteristic feature seen in almost all cases. .T1-weighted MRI scans showed hyperintense foci . T1-weighted post-gadolinium scans showed heterogeneous enhancement . T2-weighted images showed heterogeneous signals . Angiography (traditional or magnetic resonance angiography [MRA]) exclusive external carotid supply for lesions less than 3 cm. Tumors greater than 3 cm were supplied by external carotid, internal carotid, and posterior fossa circulation arteries. Bilateral Endolymphatic sac tumors are pathognomonic of Von Hippel Lindau Disease. The lesion can be differentiated from 1.Cholesterol Granuloma (lesion centred over petrous apex ; smooth expansion with bony dehiscence ; Typical T1 hyperintensity and peripheral hypointense rim in T2W1) 2. Glomus Juglare –epicentre over Jugular foramen.
Ref: The Laryngoscope - Volume 116, Issue 1, pages 40–46,January 2006 The Radiologic Diagnosis of Endolymphatic Sac Tumors Nirmal P. Patel
Contributed By:
Dr. Babu Peter MD, DNB
Associate Professor, Barnard Institute of Radiology
Senior Consultant Radiologist, Aarthi Scans, Chennai