Letter to the Editor

The current trend of proximal tibiofibular ganglion cyst: A summary of 7 case series and 61 case reports

Purpose

To review the different types of ganglion cysts surrounding the proximal tibio-fibular joint, their management options, outcomes, and recurrence.

Design

Descriptive analytical review.

Results

7 case series consisting of a total of 159 patients and 61 case reports consisting of 80 patients (with three patients having bilateral pathology) were included in this review. (Total cysts 159 + 83 = 242). The mean age was 41 years, and 71 % of the patients were males. 96.5 % of the cases were managed operatively, out of which 98 % of patients felt improvement in local symptoms and 71.5 % had improvement in neurological symptoms. Complete excision of the cyst is the primary mode of operative management. Many added procedures with complete excision are to mitigate the risk of recurrence. The recurrence rate of aspiration, simple excision alone, simple excision with recurrent articular branch neurectomy, and simple excision with PTFJ procedures were 77 %, 56 %, 11.5 %, and 0 %, respectively. Outcomes beyond recurrence were poorly reported.

Conclusion

There is not enough literature regarding the topic from which any formal systematic review can be done. Our summary suggests that aspiration alone or with steroid injection is associated with the highest recurrence rates among all the procedures. Complete excision with recurrent articular branch neurectomy should be the primary management. Revision cyst excision in isolation is an inadequate treatment option, therefore should be done in conjunction with PTFJ arthrodesis, which reduces the recurrence rates. Better quality studies are needed that report patient-centered outcomes and morbidities following PTFJ procedures.

Intraneural ganglion cysts: a systematic review and reinterpretation of the world's literature

OBJECTIVE The etiology of intraneural ganglion cysts has been controversial. In recent years, substantial evidence has been presented to support the articular (synovial) theory for their pathogenesis. The authors sought to 1) perform a systematic review of the world's literature on intraneural cysts, and 2) reinterpret available published MR images in articles by other authors to identify unrecognized joint connections. METHODS In Part 1, all cases were analyzed for demographic data, duration of symptoms, the presence of a history of trauma, whether electromyography or nerve conduction studies were performed, the type of imaging, surgical treatment, presence of a joint connection, intraneural cyst recurrence, and postoperative imaging. Two univariate analyses were completed: 1) to compare the proportion of intraneural ganglion cyst publications per decade and 2) to assess the number of recurrences from 1914 to 2003 compared with the years 2004-2015. Three multivariate regression models were used to identify risk factors for intraneural cyst recurrence. In Part 2, the authors analyzed all available published MR images and obtained MR images from selected cases in which joint connections were not identified by the original authors, specifically looking for unrecognized joint connections. Two univariate analyses were done: 1) to determine a possible association between the identification of a joint connection and obtaining an MRI and 2) to assess the number of joint connections reported from 1914 to 2003 compared with 2004 to 2015. RESULTS In Part 1, 417 articles (645 patients) were selected for analysis. Joint connections were identified in 313 intraneural cysts (48%). Both intraneural ganglion cyst cases and cyst recurrences were more frequently reported since 2004 (statistically significant difference for both). There was a statistically significant association between cyst recurrence and percutaneous aspiration as well as failure to disconnect the articular branch or address the joint. In Part 2, the authors identified 43 examples of joint connections that initially went unrecognized: 27 based on their retrospective MR image reinterpretation of published cases and 16 of 16 cases from their sampling of original MR images from published cases. Overall, joint connections were more commonly found in patients who received an MRI examination and were more frequently reported during the years 2004 to 2015 (statistically significant difference for both). CONCLUSIONS This comprehensive review of the world's literature and the MR images further supports the articular (synovial) theory and provides baseline data for future investigators.

An inferior alveolar intraneural cyst: a case example and an anatomical explanation to support the articular theory within cranial nerves

The authors describe the case of an intraneural ganglion cyst involving a cranial nerve (V3), which was found to have a joint connection in support of an articular origin within the cranial nerves. An inferior alveolar intraneural cyst was incidentally discovered on a plain radiograph prior to edentulation. It was resected from within the mandibular canal with no joint connection perceived at surgery. Histologically, the cyst was confirmed to be an intraneural ganglion cyst. Reinterpretation of the preoperative CT scan showed the cyst arising from the temporomandibular joint. This case is consistent with the articular (synovial) theory of intraneural ganglion cysts. An anatomical explanation and potential joint connection are provided for this case as well as several other cases of intraneural cysts in the literature, and thus unifying cranial nerve involvement with accepted concepts of intraneural ganglion cyst formation and propagation.

Intraneural pseudocyst (so-called ganglion) in an unusual retroperitoneal periadnexal location?

A case of an unusual unilocular cystic lesion of diameter 7 cm located retroperitoneally in the pelvis in close connection to the right adnexa of a 61 year-old woman is presented. Macroscopically, the lesion had a smooth outer and inner surface and was filled with translucent fluid. Histological examination revealed a fibrous and hyalinized wall which lacked a specific lining. Numerous nerve bundles in the cyst wall constituted the most conspicuous element of its histology possibly with some contribution of perineurial and/or mesothelial components. The morphology and immunohistochemistry speak for an intraneural pseudocyst sometimes called intraneural ganglion cyst which is rare in this location.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1357862917132314.