Ganglion cyst of the temporomandibular joint with intradural extension: case report

Aaron P. Kamer Departments of Radiology and Imaging Sciences, and

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Jose M. Bonnin Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, Indiana;

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Robert J. Spinner Department of Neurologic Surgery, Mayo Clinic and Mayo Foundation, Rochester, Minnesota; and

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Aaron A. Cohen-Gadol Goodman Campbell Brain and Spine, Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana

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Intracranial extension of temporomandibular joint (TMJ) ganglion cysts is very rare. Two previously reported cases presented clinically due to effects on cranial nerves and had obvious association with the TMJ on imaging. To the authors’ knowledge, intracranial extension of a TMJ ganglion cyst presenting with seizures and mimicking a primary brain tumor has not been previously reported. The patient underwent resection of a presumptive primary cystic temporal lobe tumor, but the lesion had histopathological features of a nonneoplastic cyst with a myxoid content. He was followed with serial imaging for 5 years before regrowth of the lesion caused new episodes of seizures requiring a repeat operation, during which the transdural defect was repaired after the adjacent segment of the TMJ was curetted. A thorough review of all imaging studies and the histopathological findings from the repeat operation led to the correct diagnosis of a TMJ ganglion cyst. This case highlights an unusual presentation of this rare lesion, as well as its potential for recurrence. TMJ ganglion cysts should be included in the differential diagnosis of cystic tumors involving the anterior temporal lobe, presenting with or without seizures. Focused imaging evaluation of the TMJ can be helpful to rule out the possible role of associated TMJ lesions.

ABBREVIATIONS

GFAP = glial fibrillary acidic protein; TMJ = temporomandibular joint.

Intracranial extension of temporomandibular joint (TMJ) ganglion cysts is very rare. Two previously reported cases presented clinically due to effects on cranial nerves and had obvious association with the TMJ on imaging. To the authors’ knowledge, intracranial extension of a TMJ ganglion cyst presenting with seizures and mimicking a primary brain tumor has not been previously reported. The patient underwent resection of a presumptive primary cystic temporal lobe tumor, but the lesion had histopathological features of a nonneoplastic cyst with a myxoid content. He was followed with serial imaging for 5 years before regrowth of the lesion caused new episodes of seizures requiring a repeat operation, during which the transdural defect was repaired after the adjacent segment of the TMJ was curetted. A thorough review of all imaging studies and the histopathological findings from the repeat operation led to the correct diagnosis of a TMJ ganglion cyst. This case highlights an unusual presentation of this rare lesion, as well as its potential for recurrence. TMJ ganglion cysts should be included in the differential diagnosis of cystic tumors involving the anterior temporal lobe, presenting with or without seizures. Focused imaging evaluation of the TMJ can be helpful to rule out the possible role of associated TMJ lesions.

Ganglion cysts arise from the capsule of synovial joints throughout the body, most typically in the dorsum of the hands and wrists,7 where ganglion cysts represent approximately 60% of tumors.8 In the temporomandibular joint (TMJ), ganglion cysts are much less common and usually manifest clinically by the presence of swelling and sometimes pain in the preauricular region or in the parotid gland.5 Unusual ganglion cysts associated with the TMJ have been reported, including “intraneural cysts” resulting in compression of the trigeminal nerve, hypoglossal nerve, and auriculotemporal nerve at the level of the skull base.3 A review of the literature also disclosed 2 previous case reports of TMJ ganglion cysts extending through the bony glenoid fossa into the middle cranial fossa and causing symptoms other than the typical swelling and pain.4,9 No previous reports describe TMJ ganglion cysts presenting with seizures or mimicking a cystic brain tumor.

We reviewed previously reported cases of intracranial TMJ cysts and present the case of an intracranial ganglion cyst presenting with seizures. The patient, a 49-year-old man, initially harbored a cystic lesion in the left temporal lobe that was suspected to be a cystic primary brain neoplasm. The lesion was resected, and histopathological examination revealed a nonneoplastic cystic lesion with myxoid content. Five years later, he suffered from recurrence of his seizures and underwent a reoperation.

Case Report

History and Examination

A previously healthy 49-year-old man presented to the emergency department with a new onset of tonic-clonic seizures. The initial workup included contrast-enhanced head CT that demonstrated a 2.5-cm-diameter, round, low-density lesion in the inferior left temporal lobe (Fig. 1). Follow-up MRI (Fig. 2) showed a cystic lesion, apparently within the inferoanterior left temporal lobe, with surrounding FLAIR hyperintensity. Only a small focus of enhancement was present, along the floor of the middle cranial fossa at the inferior aspect of the cystic lesion.

FIG. 1.
FIG. 1.

A: After initial seizure, axial contrast-enhanced CT demonstrated a low-density, nonenhancing lesion in the left middle cranial fossa, apparently within the left temporal lobe. B: Unobserved at the time, a small region of bony rarefaction (arrow) was present in the floor of the left middle cranial fossa along the roof of the TMJ.

FIG. 2.
FIG. 2.

Initial coronal FLAIR (A) and postcontrast T1-weighted (B) images demonstrate the cystic lesion in the left temporal lobe with surrounding FLAIR hyperintensity (black arrow) that likely represents reactive temporal lobe gliosis. The small cystic/solid nodule at the inferior margin demonstrates enhancement (open arrow) that is nonspecific but typical of granulation tissue. This tissue has apparent communication with the glenoid fossa.

First Operation and Histopathology

A left temporal craniotomy led to gross-total resection of the cystic lesion. The discolored, calcified dura along the floor of the middle fossa was also biopsied. The cyst was intradural and intraparenchymal. The wall of the cyst was entirely removed and consisted of dense fibrous tissue and contained some small mononuclear cells and histiocytes. It was adherent to the nervous tissue, which showed intense immunopositivity for synaptophysin and glial fibrillary acidic protein (GFAP). Fingerlike projections of the fibrous tissue extended from the outer surface of the cyst wall and were closely intermingled with the nervous tissue (Fig. 3). The cyst cavity did not reveal an epithelial lining, and it contained a thin myxoid material that stained positive for Alcian blue. Prominent reactive gliosis (Fig. 4A and B), microglial cells, histiocytes, and occasional small mononuclear cells were noted in the nervous tissue but there was no evidence of a neoplastic process. Occasional islands of hyaline cartilage were also observed in the midst of the dense fibrous tissue (Fig. 4C). In retrospect, a small defect was likely present in the floor of the left middle cranial fossa (Fig. 1B).

FIG. 3.
FIG. 3.

Ganglion cyst from the left TMJ. Note the dense fibrous tissue wall of the cyst and the absence of epithelial lining (A and D), rich mucinous content of the cyst cavity (B and E), and the profuse reactive glial proliferation associated with the cyst wall (C and F). H & E (A and D), Alcian blue pH 2.5 (B and E), and GFAP (C and F). Original magnification ×20 (A–C), ×100 (D–F). Figure is available in color online only.

FIG. 4.
FIG. 4.

Gliotic tissue in white matter of the anterior left temporal lobe (A) and the complex interface between the gliotic white matter and the fibrous outer surface of the cyst wall (B). Island of hyaline cartilage, presumably from the TMJ surface (C). GFAP (A and B), H & E (C). Original magnification ×200 (A), ×100 (B and C). Figure is available in color online only.

Seizure Recurrence

The postoperative course was uncomplicated. The patient was followed with serial MRI examinations over almost 5 years without evidence of recurrence. Late in the 4th postoperative year and almost 1 year since his last unremarkable MRI, the patient suffered from another episode of generalized seizures associated with postictal right-sided weakness after an unrelated medical procedure. MRI obtained at that time demonstrated similar findings to the original MRI, with a recurrent cystic lesion in the left temporal lobe (Fig. 5).

FIG. 5.
FIG. 5.

The patient’s sagittal postcontrast preoperative MR image (patient’s anterior on the right) demonstrates recurrence of the cystic lesion in the left middle cranial fossa, with unusual enhancement and thickening of the bony roof of the glenoid fossa (arrow). A small amount of nodular enhancement representing granulation tissue is also present along the floor of the middle cranial fossa.

Although the histopathological findings would eventually prove the cysts to be extraaxial, the appearance of the 3-cm temporal lobe cyst on the new MRI was strongly suggestive of an intraaxial process, without any identifiable intervening gray matter or CSF between the lesion and the adjacent white matter. A small amount of FLAIR-hyperintense edema or gliosis was present in the white matter of the left temporal lobe.

Detailed evaluation of the new and previous imaging studies revealed partial fragmentation, abnormal density, and possibly erosive changes of the bony temporomandibular glenoid fossa in the floor of the left middle cranial fossa adjacent to the cystic lesion. Thin-slice CT images through the TMJs (Fig. 6) demonstrated thickening and a ground-glass rarefactive appearance of the bony glenoid fossa with regions of possible bone defect. The TMJ itself showed a few small peripheral calcifications, raising suspicion for pseudogout with TMJ involvement. In addition to the standard images, small field-of-view postcontrast images through the TMJ revealed abnormal enhancement in the bony glenoid fossa and a 3-mm nodule of adjacent intracranial soft-tissue density along the floor of the left middle cranial fossa (Fig. 5).

FIG. 6.
FIG. 6.

After 5 years of postresection stability and MRI-evident recurrence, a soft-tissue algorithm coronal CT image (A) also demonstrates recurrence of the middle cranial fossa ganglion cyst. Bone algorithm coronal CT image (B) demonstrates abnormal thickening and rarefaction of the bony roof of the left glenoid fossa (white arrow), through which the ganglion cyst entered the middle cranial fossa. Small calcific fragments around the mandibular condyle (open arrow) likely represent findings of calcium pyrophosphate deposition disease (pseudogout), which commonly occurs in the TMJ and may have predisposed this patient to the degeneration of the joint capsule leading to the ganglion cyst. Changes of previous left temporal craniotomy are also visible.

Second Operation and Histopathology

A cystic process arising from the TMJ was suspected and re-resection of the left temporal lobe lesion was undertaken. The cyst contained clear fluid. The nodule along the floor of the middle cranial fossa (the location of the biopsy during the first operation) was removed and found to clearly communicate with the TMJ (Fig. 7, Video 1).

VIDEO 1. Clip showing a ganglion cyst of the TMJ with intradural extension. Copyright Aaron Cohen-Gadol. Published with permission from Neurosurgical Atlas by Aaron Cohen-Gadol. Click here to view.

FIG. 7.
FIG. 7.

A: Intraoperative view with demonstration of the direct connection (arrow) between the cyst cavity and the TMJ. B: Artist’s rendering of the TMJ origin of this ganglion cyst with erosion through the floor of the middle cranial fossa and mass effect upon the temporal lobe, ultimately leading to seizures in our patient. Copyright Aaron Cohen-Gadol. Published with permission from Neurosurgical Atlas by Aaron Cohen-Gadol. Figure is available in color online only.

After resection of the abnormal tissue over the TMJ, a piece of dural allograft was used to cover the floor of the middle cranial fossa where the connection to the joint was apparent. The patient recovered from surgery without any complication and remains seizure free.

Histopathological evaluation of the last resected lesion revealed changes similar to those observed in the first sample and were compatible with a ganglion cyst. Reactive gliosis was observed in the nervous tissue adherent to the cyst wall.

Discussion

A variety of TMJ lesions can erode the bony structures that comprise the joint, including a number of tumors and pseudotumors.6 TMJ cysts, however, are nearly always extracranial. A previous review of the literature revealed that these cysts typically present with swelling and sometimes pain.5 TMJ cysts have been reported to exhibit intracranial extension in only 2 previous case reports (Table 1). In each of these cases, the patients presented with cranial neuropathy, and neither presented with seizure. One of these cysts was described as a ganglion cyst arising from the TMJ,4 while the other report generically designated the lesion as a TMJ cyst.4,9

TABLE 1.

Intracranial TMJ cysts reported in the literature

Authors & YearAge (yrs), SexPresenting ComplaintHistologySideInitial TxRecurrenceSize at Resection (cm)
Mumert et al., 201263, FCN VII palsyGanglion cystLtDrainageYes (2.5 mos)4
Vender et al., 200650, FFacial pain, maxillary division of CN VCyst w/ fibrous tissue (unspecified)RtResectionNo (2 yrs)1 × 2 (estimated from provided images)
Present case49, MSeizuresGanglion cystLtResectionYes (5 yrs)3

CN = cranial nerve; Tx = treatment.

TMJ cysts arise directly from the joint space or from the wall of the TMJ. These “cysts” are actually pseudocysts lacking a true epithelial lining, typically characterized by central myxoid content and a wall of dense fibrous tissue, with or without synovial cells. The 2 primary types of cysts arising from the TMJ are ganglion and synovial cysts, identical to similar cysts that develop in the hands and wrists. The nomenclature for these 2 cyst types has been used interchangeably in much of the literature, causing difficulty in assessing their relative frequency. Despite historically generic nomenclature, these 2 cyst types may be distinguished from each other based on their histological characteristics, including a lack of synovial cells in the wall of a ganglion cyst.2,5

The pathogenesis of TMJ ganglion cysts is thought to be the result of myxoid degeneration of the connective tissue in the capsule of the synovial joint.1,7 As a result, small cysts may form in the capsule and coalesce to form a larger, myxoid fluid-containing cyst. Over time, either through a ball-valve mechanism communicating with the joint space or through continued myxoid matrix accumulation, the cyst expands. In the hands and wrists, these cysts most commonly expand into the adjacent soft tissues, but can extend into adjacent bone, eroding and remodeling the surrounding osseous tissue but otherwise appearing histopathologically identical to extraosseous ganglion cysts.8 When associated with the TMJ, intraosseous extension of these lesions can lead to eventual involvement of the middle cranial fossa, as in our case.

A previous reported case of intracranial extension of a ganglion cyst demonstrated transdural extension,4 a finding also present in our case. We propose that the pressure from the cyst upon the dura and even cerebral parenchyma may eventually contribute to microvascular circulation compromise and relative ischemia, leading to disruption and chronic inflammation of the compressed structures, allowing continued intradural expansion of the cyst. These same changes quite likely contributed to the development of the reactive gliosis and mild chronic inflammatory cell infiltration seen in our patient. The resulting pathophysiological scenario of significant mass effect and microvascular compromise could have predisposed this patient to ultimately developing seizures.

Our initial lack of suspicion regarding the possibility of a ganglion cyst in the differential diagnosis led us to overlook the correct diagnosis during the initial evaluation in this patient. This report attempts to highlight the occurrence of this type of nonneoplastic lesion and to prevent such an event for future patients. The diagnosis of ganglion cyst should be included in the differential diagnosis of an anterior temporal lobe cystic lesion in close association with the TMJ. In addition, if the transdural defect is not appropriately repaired, these cysts can recur,10 and surveillance imaging is appropriate. However, we cannot assess the efficacy of our repair as we do not have long-term outcome data from the second operation. Continual follow-up imaging is necessary.

Intracranial extension of TMJ cysts is a rare entity that may traverse the dura mater and predispose a patient to seizures. A small but growing number of case reports reveal that bony and intracranial extension of TMJ cysts, although rare, may present with a variety of location-based symptoms, including seizures. The available literature and the current case suggest that recurrence of these cysts is common. A high index of suspicion and careful attention to the glenoid fossa on imaging evaluation of middle cranial fossa cysts will enable detection of this unusual mass. Preoperative planning for adequate management of glenoid fossa disruption is essential for purposes of appropriate repair and recurrence prevention.

Disclosures

Dr. Spinner reports being a consultant for Mayo Medical Ventures.

Author Contributions

Conception and design: Cohen-Gadol, Kamer. Acquisition of data: Bonnin, Spinner. Analysis and interpretation of data: all authors. Drafting the article: Cohen-Gadol, Kamer. Critically revising the article: Cohen-Gadol, Kamer. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Cohen-Gadol.

Supplemental Information

References

  • 1

    Ackerman LV, Rosai J: Surgical Pathology, ed 5. St. Louis, MO: Mosby, 1974

  • 2

    Bonacci CE, Lambert BJ, Pulse CL, Israel HA: Inflammatory synovial cyst of the temporomandibular joint: a case report and review of the literature. J Oral Maxillofac Surg 54:769773, 1996

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3

    Capek S, Koutlas IG, Strasia RP, Amrami KK, Spinner RJ: An inferior alveolar intraneural cyst: a case example and an anatomical explanation to support the articular theory within cranial nerves. J Neurosurg 122:14331437, 2015

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4

    Mumert ML, Altay T, Shelton C, Harnsberger HR, Couldwell WT: Ganglion cyst of the temporomandibular joint with intracranial extension in a patient presenting with seventh cranial nerve palsy. J Neurosurg 116:310312, 2012

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5

    Nahlieli O, Lewkowicz A, Hasson O, Vered M: Ganglion cyst of the temporomandibular joint: report of case and review of literature. J Oral Maxillofac Surg 58:216219, 2000

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 6

    Poveda-Roda R, Bagán JV, Sanchis JM, Margaix M: Pseudotumors and tumors of the temporomandibular joint. A review. Med Oral Patol Oral Cir Bucal 18:e392e402, 2013

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 7

    Rosai J: Rosai and Ackerman’s Surgical Pathology, ed 10. New York: Mosby, 2011, pp 20702071

  • 8

    Thornburg LE: Ganglions of the hand and wrist. J Am Acad Orthop Surg 7:231238, 1999

  • 9

    Vender JR, Hughes BD, Figueroa R, Jensen MA: Temporomandibular joint cyst presenting as trigeminal neuropathy and middle fossa mass: case report. Neurosurgery 59:E938, 2006

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10

    Wu CI, Liu KW, Hsu YC, Chiang IP, Chang SC: Treatment of temporomandibular joint ganglion cyst. J Craniofac Surg 22:19351937, 2011

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An artists depiction of a proposed method to deliver endovascular care via a teleoperated robot in space. A patient located on a satellite orbiting the Earth is undergoing a telesurgical endovascular intervention via the CorPath device. Real-time angiography images are beamed back to Earth, where an operator (in this case, a humanoid robot) is controlling the robot over a long distance. Copyright Gavin W. Britz. Published with permission. See the article by Panesar et al. (pp 971–978).

  • FIG. 1.

    A: After initial seizure, axial contrast-enhanced CT demonstrated a low-density, nonenhancing lesion in the left middle cranial fossa, apparently within the left temporal lobe. B: Unobserved at the time, a small region of bony rarefaction (arrow) was present in the floor of the left middle cranial fossa along the roof of the TMJ.

  • FIG. 2.

    Initial coronal FLAIR (A) and postcontrast T1-weighted (B) images demonstrate the cystic lesion in the left temporal lobe with surrounding FLAIR hyperintensity (black arrow) that likely represents reactive temporal lobe gliosis. The small cystic/solid nodule at the inferior margin demonstrates enhancement (open arrow) that is nonspecific but typical of granulation tissue. This tissue has apparent communication with the glenoid fossa.

  • FIG. 3.

    Ganglion cyst from the left TMJ. Note the dense fibrous tissue wall of the cyst and the absence of epithelial lining (A and D), rich mucinous content of the cyst cavity (B and E), and the profuse reactive glial proliferation associated with the cyst wall (C and F). H & E (A and D), Alcian blue pH 2.5 (B and E), and GFAP (C and F). Original magnification ×20 (A–C), ×100 (D–F). Figure is available in color online only.

  • FIG. 4.

    Gliotic tissue in white matter of the anterior left temporal lobe (A) and the complex interface between the gliotic white matter and the fibrous outer surface of the cyst wall (B). Island of hyaline cartilage, presumably from the TMJ surface (C). GFAP (A and B), H & E (C). Original magnification ×200 (A), ×100 (B and C). Figure is available in color online only.

  • FIG. 5.

    The patient’s sagittal postcontrast preoperative MR image (patient’s anterior on the right) demonstrates recurrence of the cystic lesion in the left middle cranial fossa, with unusual enhancement and thickening of the bony roof of the glenoid fossa (arrow). A small amount of nodular enhancement representing granulation tissue is also present along the floor of the middle cranial fossa.

  • FIG. 6.

    After 5 years of postresection stability and MRI-evident recurrence, a soft-tissue algorithm coronal CT image (A) also demonstrates recurrence of the middle cranial fossa ganglion cyst. Bone algorithm coronal CT image (B) demonstrates abnormal thickening and rarefaction of the bony roof of the left glenoid fossa (white arrow), through which the ganglion cyst entered the middle cranial fossa. Small calcific fragments around the mandibular condyle (open arrow) likely represent findings of calcium pyrophosphate deposition disease (pseudogout), which commonly occurs in the TMJ and may have predisposed this patient to the degeneration of the joint capsule leading to the ganglion cyst. Changes of previous left temporal craniotomy are also visible.

  • FIG. 7.

    A: Intraoperative view with demonstration of the direct connection (arrow) between the cyst cavity and the TMJ. B: Artist’s rendering of the TMJ origin of this ganglion cyst with erosion through the floor of the middle cranial fossa and mass effect upon the temporal lobe, ultimately leading to seizures in our patient. Copyright Aaron Cohen-Gadol. Published with permission from Neurosurgical Atlas by Aaron Cohen-Gadol. Figure is available in color online only.

  • 1

    Ackerman LV, Rosai J: Surgical Pathology, ed 5. St. Louis, MO: Mosby, 1974

  • 2

    Bonacci CE, Lambert BJ, Pulse CL, Israel HA: Inflammatory synovial cyst of the temporomandibular joint: a case report and review of the literature. J Oral Maxillofac Surg 54:769773, 1996

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 3

    Capek S, Koutlas IG, Strasia RP, Amrami KK, Spinner RJ: An inferior alveolar intraneural cyst: a case example and an anatomical explanation to support the articular theory within cranial nerves. J Neurosurg 122:14331437, 2015

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4

    Mumert ML, Altay T, Shelton C, Harnsberger HR, Couldwell WT: Ganglion cyst of the temporomandibular joint with intracranial extension in a patient presenting with seventh cranial nerve palsy. J Neurosurg 116:310312, 2012

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 5

    Nahlieli O, Lewkowicz A, Hasson O, Vered M: Ganglion cyst of the temporomandibular joint: report of case and review of literature. J Oral Maxillofac Surg 58:216219, 2000

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 6

    Poveda-Roda R, Bagán JV, Sanchis JM, Margaix M: Pseudotumors and tumors of the temporomandibular joint. A review. Med Oral Patol Oral Cir Bucal 18:e392e402, 2013

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 7

    Rosai J: Rosai and Ackerman’s Surgical Pathology, ed 10. New York: Mosby, 2011, pp 20702071

  • 8

    Thornburg LE: Ganglions of the hand and wrist. J Am Acad Orthop Surg 7:231238, 1999

  • 9

    Vender JR, Hughes BD, Figueroa R, Jensen MA: Temporomandibular joint cyst presenting as trigeminal neuropathy and middle fossa mass: case report. Neurosurgery 59:E938, 2006

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10

    Wu CI, Liu KW, Hsu YC, Chiang IP, Chang SC: Treatment of temporomandibular joint ganglion cyst. J Craniofac Surg 22:19351937, 2011

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