Cystic lesions of peripheral nerves: Are we missing the diagnosis of the intraneural ganglion cyst?

Table 4 Magnetic resonance features differentiating intraneural ganglion cyst from extraneural ganglion cyst

	Intraneural ganglion cyst	Extraneural ganglion cyst
Cyst size	Small	Large
Cyst shape	Tubular beaded configuration	Globular
Cyst pattern and location	It is along the course of the nerve and its branches with no fat plane between the cyst and the nerve	It does not follow the course of the nerve; the nerve is seen separately from the cyst with an intervening preserved fat plane; usually located in between the fibula and peroneus longus muscle, with or without an intramuscular extension
PTF joint connection	Is present and the tail lies anteromedial to proximal fibula between 10-12 o’clock position on axial MR images	Is present but located more superiorly and anterolateral to the proximal fibula at 12-2 o’clock position on axial MR images
Relation with fibula	The extension of the cyst along the articular branch appears to cross the fibula from medial to lateral (“Transverse limb sign”)	The cyst never crosses the fibula and always lies anterior, anterolateral or lateral to the fibula (Absent “Transverse limb sign”)
Muscle denervation	Common	Uncommon

MR: Magnetic resonance; PTF: Proximal tibiofibular.