Subdural hygroma after spontaneous rupture of an arachnoid cyst in a pediatric patient: A case report

Abstract

Arachnoid cysts are benign masses that represent a relatively small percentage of intracranial lesions. Spontaneous rupture of an arachnoid cyst resulting in a subdural hygroma is a very rare event. We report a case of a pediatric patient with a history of an arachnoid cyst and chronic headaches presenting with bilateral papilledema, worsening headaches, and no history of head trauma. Magnetic resonance imaging of the brain revealed an extra-axial cystic lesion in the right middle cranial fossa, similar to an arachnoid cyst seen on previous imaging. A new right subdural collection similar to the cerebral spinal fluid signal causing mass effect on brain parenchyma was determined to represent a subdural hygroma. Craniotomy was performed to evacuate the subdural hygroma as well as cyst fenestration. We report this case to emphasize the importance of considering spontaneous rupture of an arachnoid cyst as a differential diagnosis despite absence of head trauma.

Ruptured Sylvian arachnoid cysts: an update on a real problem

“…The majority of these cases were described as isolated cases or small series, apart from 3 series of 32 [ 18 ], 44 [ 19 ], and 60 cases [ 20 ], respectively. The main characteristics of these patients are reported in detail in Table 1 [ 6 – 8 , 10 – 16 , 18 – 129 ]. The results are summarized in Table 2 and analyzed in the “Discussion” section.…”

“…As mentioned, a traumatic event is reported “only” in a half of the patients but the relatively high rate of “spontaneous” ruptures might depend on misdiagnosed, mild traumas, or on events that are not considered traumatic (e.g. cough, Valsalva maneuver, physical exercise) [ 16 , 30 , 39 ]. Actually, even an abrupt movement of the head could cause the impact of the cyst against the sphenoid wing, thus causing its rupture.…”

“…It is a common experience, in the clinical practice, to find a variable amount of blood diluted in the hygroma of a ruptured pediatric SAC. Actually, hygroma is thought to originate from the laceration of the cyst wall after contact with the sphenoidal wing as well, with subsequent CSF escape into the subdural space [7,16,23]. Such a communication between the intracystic and the subdural space was detected during surgery by some authors in the past [39,40,100].…”

“…This event seems to be peculiar of SACs where the risk of rupture is higher compared with intracranial arachnoid cysts located elsewhere [6,7]. The cyst rupture raises a great interest among the scientific community because of the possible emergency implications and the variable clinical presentation and course, as demonstrated by the large number of reports published even in recent years [8][9][10][11][12][13][14][15][16]. Moreover, the management of ruptured SACs still represents a controversial problem for neurosurgeons as far as the surgical indication and the type of treatment are concerned.…”

Spontaneous rupture of arachnoid cyst

“…Arachnoid cysts (ACs) are benign collections of cerebrospinal fluid (CSF), which represent a relatively small percentage of intracranial lesions. [ 1 ] Their incidence is reported at about 1% of all intracranial masses and is generally detected incidentally or on investigating symptoms after rupture. [ 1 , 2 ] With advancing imaging techniques such as magnetic resonance imaging (MRI) and increased availability of imaging, the reporting of ACs has increased in the past two decades.…”