Rapid spontaneous resolution of lumbar ganglion cysts: A case report

Abstract

BACKGROUND

To discuss the rare event of spontaneous resolution of a lumbar ganglion cyst, a personal case report and 25 cases culled from the literature were described in detail. We focused on demographic, classification, clinical and radiological findings, treatment, outcome and radiological resolution.

CASE SUMMARY

A 51-year-old man presented to our observation with complaints of low back and right leg pain. Lumbar magnetic resonance imaging (MRI). showed a L4-L5 ganglion cyst. The patient was referred to medical therapy and bracing. After 4 wk, he showed a complete resolution of pain. The complete spontaneous resolution of the cyst was demonstrated by the followed-up MRI.

CONCLUSION

Spontaneous resolution of lumbar ganglion is very rare and only 26 cases, including ours, were reported in literature. Different degrees of biomechanical impairment seem to play a fundamental role in the pathogenesis. Related symptoms are essentially represented by low back and/or radicular pain, without significant neurological disorders. Anti-inflammatory drugs, light unloading exercises and brace could be recommended to administrated pain and decrease facet loads. Mean time for clinical improvement was 7 mo, while MRI disappearance occurred in an average time of 11 mo. Therefore, surgery should be applied when conservative treatment, prolonged at least 6 mo, fails.

Key Words: Lumbar ganglion cyst; Spontaneous resolution; Conservative treatment; Radiological disappearance; Case report

Core tip: Our paper is an original study that analyzes in detail and for the first time, on the basis of a personal observation, the clinical and radiological scenario related to the rare spontaneous resolution of a lumbar ganglion cyst. The term “ganglion cyst” was used according to the recent our morphological classification. Discussing natural history and biomechanical features of this pathology, we propose some recommendations that could be adopted in cases with a propensity to spontaneous resolution.

INTRODUCTION

Spinal articular cysts are more frequently found in the lumbar spine and often they are treated by surgical cystectomy, with or without spinal instrumentation. Recently, the term “ganglion” was proposed to identify the pathological entity, together with an original morphological classification to define possible localizations[1]. Remission of this type of cyst after conservative treatment was not so frequently reported in literature[2]. We report a case of clinical and radiological resolution of a symptomatic lumbar ganglion cyst (LGC) after conservative treatment, discussing mechanisms that could have led to its disappearance.

CASE PRESENTATION

Chief complaints

A 51-year-old man presented to our observation with complaints of low back and right leg pain with a L5 dermatomeric distribution.

History of past illness

His disorders persisted from 10 d.

Personal and family history

Personal and family history were negative for medical or surgical diseases.

Laboratory examinations

Lasègue test was highly positive, without neurological deficits. Tendon reflexes were normal. Laboratory tests were normal.

Imaging examinations

Lumbar MRI showed a cystic lesion in the L4-L5 spinal canal, medial and adjacent to the right internal facet joint, iso-hypointense in T1 and hyperintense in T2-weighted images, compatible with a ganglion cyst.

FINAL DIAGNOSIS

Final diagnosis was: A symptomatic right L4-L5 LGC.

TREATMENT

After discussion on treatment options, the patient was referred to medical therapy, based on NSAID, SAID for 10 d and lumbar bracing. Clinical follow-up was instituted after 4 wk, advising the patient to call us in case of neurological worsening. Surprisingly, 4 wk later, the patient showed complete resolution of the symptoms. We scheduled a new lumbar MRI after 2 d, in order to evaluate the evolution of the lesion. T1 and T2 sequences demonstrated the complete resolution of the LGC as well as compression of the right L5 nerve root (Figure 1).

Figure 1 Radiological detection of the spontaneous disappearance of our right L4-L5 ganglion cyst, comparison of magnetic resonance imaging findings at observation (time 0) and follow-up (1 mo). A: Sagittal T2 images; B: Sagittal STIR T2 images; C: Axial T2 images: note the decrease of interfacet fluid amount at 1 mo follow-up.

We conducted a PubMed research on literature published until October 2018. The search was undertaken using the keywords ‘‘lumbar cyst”, “ganglion cyst’’, ‘‘synovial cyst’’, “juxtafacet cyst”, “facet joint cyst”, and “resolution”. References from the retrieved reports were checked to identify other possible results. We enrolled cases with radiological documented remission of LGC and/or clinical improvement after conservative treatment based on rest, lumbar bracing, drugs and/or kinesiotherapy, excluding all those treated by surgery or deep percutaneous procedures (e.g. radiofrequency, epidural injection etc). For every case collected, we analyzed age, sex, symptoms, neurological deficits and treatment received. When radiological data were available, we classified the localization of the LGC following our previous original classification[1] and we searched for the presence of instability signs, even in the follow-up images. Outcome clinical data were classified in 4 categories: (1) Excellent; (2) Good; (3) Fair; or (4) Poor, according to Macnab[3] (Table 1).

Table 1 Macnab[3] criteria used for measuring outcome.

Grade	Criteria
Excellent	No pain; no restriction of activity
Good	Occasional back or leg pain of sufficient severity to interfere with the patient’s ability to do his normal work
Fair	Improved functional capacity, but handicapped by intermittent pain of sufficient severity to curtail or modify work or leisure activities
Poor	No improvement or insufficient improvement to enable increase in activities; further operative intervention required

OUTCOME AND FOLLOW-UP

Demographic, clinical and radiological data were summarized in Table 2. The total number of cases, including ours, was 26. Male: Female ratio was 1.6 (16 males and 10 females) and the mean age was 56 (range 15-75). Most of localizations were in L4-L5 (17; 65%), followed by L5-S1 (6; 23%) and L3-L4 (3; 12%). In 1 case LGCs were bilateral. All classified LGCs (21; 81%) were in the spinal canal and medium: Medium-external in 9 cases (33%), medium-internal in 4 (15%), purely medium in 7 (26%); 1 case (4 %) was purely external (intra-foraminal); in 6 cases (22%) there were no data available to classify the LGC. In all papers the radiological diagnosis was made by MRI, except for 2 cases published before year 2000 in which diagnosis was made by CT scans. Associated spondylolisthesis was detected in 5 (19%) cases, while increased interfacet fluid in 9 (33%). Clinical presentation was constantly characterized by single or double radiculopathy due to irritation of exiting and/or traversing nerve roots. Low back pain accompanied radicular pain 11 times (42%), while pure low back pain was the only symptom in 2 cases (8%). Sensory radicular deficits were identified in 4 cases (15%). There were no cases of motor deficits. Before observation, the mean duration of symptoms was 6.8 mo (range 5 d - 36 mo). When reported (18 cases; 70%), among conservative treatments, a lumbar brace was used in 5 cases (28%), nonsteroidal anti-inflammatory drugs in 13 (72%), corticosteroids in 2 (11%) as well as gabapentin. Rest was recommended in 10 cases (55%), while kinesiotherapy (especially unloading exercises) in 8 (44%). Chiropractic manipulation was performed on 4 patients (22%). Radiological reduction or resolution of the lesion were evaluated by CT or MRI in 21 cases (81%), but in 4 cases images were not available in papers. The mean time for radiological resolution was 11 mo (range 2 d - 48 mo). Signs of instability remained unchanged, except in 2 cases (13%) for reduction of interfacet fluid amount. The mean time for clinical improvement was 7 mo (range 2 d - 24 mo). Final clinical condition was good or excellent in all cases.

Table 2 Regression of lumbar ganglion cyst: Our case and 25 from literature.

	Author/Yr	Age	Sex	Level/ Side	Classification1	Imaging	Instability	Symptoms	Duration	Deficit	Treat-ment	Imag-ing control/Time	Instability control	Control	Out-come2
1	Mercader et al[2], 1985	65	F	L4-L5/ right	Med-Int	CT	SPL	Rad	8 mo	\	Rest-NSAID-KT-brace	CT reduction/3 mo	SPL	3 mo	Good
2	Coulier et al[4], 1998	47	F	L4-L5/bilat	Med/ Med	CT	NR	LBP	NR	\	Brace	CT/20 mo: left resolution, right reduced	NR	20 mo	Excel-lent
3	Maezawa et al[5], 2000	15	M	L4-L5/left	Med	MRI	NR	LBP + Rad	2 mo	\	Brace	MRI resolution/3 mo	NR	3 mo	Excel-lent
4	Houten et al[6], 2003	64	M	L4-L5/ right	NA	MRI	NR	LBP + Rad	7 mo	\	Conservative (na)	MRI resolution/1 mo (na images)	NR	1 mo	Good
5		57	F	L4-L5/left	NA	MRI	NR	Rad	5 mo	\	NSAID-gabap-entin	MRI resolution/8 mo (na images)	NR	8 mo	Good
6		58	F	L4-L5/left	Med-Ext	MRI	NR	LBP + Rad	18 mo	\	Conservative (na)	MRI resolution/4 mo	NR	4 mo	Good
7	Swartz et al[7], 2003	58	F	L5-S1/ right	Med-Ext	MRI	SPL	Rad	1 mo	\	Rest-NSAID-KT-brace	MRI resolution/18 mo	SPL	12 mo	Good
8	Cox[8], 2005	71	M	L3-L4/ right	NA	MRI	NR	Rad	6 mo	\	Rest-NSAID- chiropractic	MRI reduction/9 mo	NR	9 mo	Good
9		59	F	L4-L5/left	Med-Ext	MRI	IFFa	Rad	NR	\	Rest-NSAID-chirop-ractic	Not performed	NR	2 mo	Excellent
10	Ewald et al[9], 2005	65	F	L4-L5/ right	Med-Ext	MRI	SPL	Rad	5 mo	\	Rest-NSAID-KT	MRI reduction/3 mo	SPL	3 mo	Good
11	Illerhaus et al[10], 2005	50	M	L4-L5/ right	Med-Int	MRI	IFFa	LBP + Rad	12 mo	\	NSAID-KT	MRI resolution/7 mo	IFFa	7 mo	Good
12	Beukelaar et al[11], 2010	59	M	L4-L5/ right	Med	MRI	IFFa	LBP + Rad	2 mo	L5 S	Conservative (na)	MRI reduction/3 mo	IFFb	3 mo	Excellent
13	Bashir et al[12], 2012	47	M	L4-L5/ right	NA	MRI	NR	Rad	6 mo	\	Rest-NSAID-KT	Not performed	NR	24 mo	Excellent
14		58	M	L4-L5/left	Med	MRI	IFFa	Rad	3 mo	\	Rest-NSAID-KT	MRI resolution/2 mo (na images)	NR	2 mo	Excellent
15		41	M	L5-S1/ right	NA	MRI	NR	Rad	12 mo	\	Rest-NSAID-KT	Not performed	NR	24 mo	Excellent
16	Barazi et al[13], 2012	48	F	L4-L5/ right	NA	MRI	NR	Rad	NR	\	Conservative (na)	MRI resolution/8 mo (na images)	NR	8 mo	Good
17	Cox et al[14], 2012	75	M	L3-L4/left	Med-Int	MRI	NR	Rad	36 mo	\	Chiropractic	Not performed	NR	2 mo	Good
18	Tepe et al[15], 2012	64	M	L5-S1/left	Ext	MRI	SPL	Rad	2 mo	L5 S	Conservative (na)	MRI reduction/1 yr, resolu-tion/4 yr	SPL	12 mo	Good
19	Mattei et al[16], 2012	56	M	L5-S1/ right	Med	MRI	IFFa	Rad	NR	S1 S	NSAID-KT	MRI resolution/13 mo	IFFa	1 mo	Excellent
20	Pulhornet al[17], 2012	72	M	L4-L5/ right	Med-Ext	MRI	IFFa	LBP	NR	\	Conservative (na)	MRI resolution/18 mo	IFFa	18 mo	Excellent
21	Ngo et al[18], 2013	58	F	L4-L5/ right	Med-Ext	MRI	NR	LBP + Rad	5 d	\	SAID-chiropractic	Not performed	NR	3 mo	Excellent
22	Kim et al[19], 2015	58	M	L3-L4/left	Med-Ext	MRI	SPL	LBP + Rad	4 mo	\	Conservative (na)	MRI resolution/4 yr	SPL	1 mo	Excellent
23	Delen et al[20], 2015	63	M	L5-S1/left	Med	MRI	IFFa	LBP + Rad	1 mo	S1 S	NSAID-gabapentin	MRI resolution/1 mo	↑IFF	1 mo	Excellent
24	Sinha et al[21], 2016	66	M	L5-S1/left	Med-Int	MRI	NR	LBP + Rad	12 mo	\	Conservative (na)	MRI resolution/12 mo	NR	12 mo	Good
25	Ucler et al[22], 2017	36	F	L4-L5/ right	Med-Ext	MRI	IFFa	LBP + Rad	10 d	\	Rest	MRI resolution/2 d	IFFa	2 d	Excellent
26	Our case	51	M	L4-L5/ right	Med-Ext	MRI	IFFa	LBP + Rad	10 d	\	Rest-NSAID-SAID-brace	MRI resolution/1 mo	IFFb	1 mo	Excellent

¹Domenicucci et al[1];

²Macnab[3]; SPL: Spondylolisthesis; IFF: Interfacet fluid; LBP: Low back pain; Rad: Radiculopathy; S: Sensory deficits; NSAID: Nonsteroidal anti-inflammatory drug; SAID: Steroidal anti-inflammatory drug; KT: Kinesiotherapy; NR: Not reported; NA: Not available data; med: Medial; int: Internal; ext: External; MRI: Magnetic resonance; CT: Computed tomography;

^aIncrease;

^bDecrease.

DISCUSSION

The number of reported synovial cysts of the lumbar spine have been increasing probably due to the availability of magnetic resonance imaging technique. Recently, the term “ganglion” and a new morphological classification were introduced to identify the pathological entity and its localization[1].

LGCs are usually associated with osteoarthritis of the adjacent facet joint, degenerative spondylosis and/or spondylolisthesis, particularly in middle aged or elderly patients. The majority of such cysts require surgical resection due to persistent radicular symptoms and/or occasional paresis[4], that could be associated to fusion if pre-operative instability is detected[1]. While ganglion cysts elsewhere (e.g. the wrist) spontaneously resolve in 40% of patients, the spontaneous resolution of root compression with radiological disappearance of LGC were rarely reported in literature.

We collected 24 cases from the literature[2,4,5] that affected the adult lumbar spine in adults and one more in the adolescent spine (Table 2)[6-22]. All ganglia, detected by CT or MRI and classified according to Domenicucci et al[1], were in the spinal canal and in medium position (95% of cases), except one reported by Tepe et al[15] that was purely external. Most were associated to indirect signs of segmental hypermobility (e.g. increase of synovial fluid) or proper instability. They were able to give, exiting and/or transiting nerve roots, irritation and compression, with prevalently single radiculopathy but without significant neurological deficits. Their resolution, demonstrated by radiological follow-up in 17 cases (68%), was always associated to substantial clinical improvement or full recovery. Indirect radiological signs of segmental instability remained unchanged after resolution, except in one case[10] in which occurred the reduction of interfacet synovial fluid amount, similar to our MRI follow-up findings.

Explaining the spontaneous resolution of LGC is complicated, in part because of the high prevalence of surgical removal. Some authors have supported the thesis that progressive degenerative changes of the facet joint lead to fixation of the previously hypermobile facets, so that intra-articular pressure decreases and the cyst shrinks[6]. The cyst may also undergo degenerative changes, losing connection with the facet joint and resolving because of a lack of supply[9]. Other possible causes for resolution include rupture, as seen in other different articular districts of the human body, with the extrusion of its contents, followed by reabsorption of the cystic wall[7]; or reduction of the local intra-articular forces that contributed to synovial herniation through the facet joint capsule. The last hypothesis could be supplied by the antigravitary lumbar bracing or unloading exercises usage in most cases described, including ours (11/19; 58%). Also chiropractic manipulations seemed clinically effective[14,18], though only one paper[8] showed the radiological resolution of the cyst. So, in our patient, who underwent treatment with NSAIDs, corticosteroids and lumbo-sacral bracing, LGC probably resolved because of the association between decreased inflammatory fluid production and microtraumatic loads.

An early clinical and radiological remission as ours is referred in only 2 cases[20,22]. Two fast clinical resolutions were previously reported, but without radiological confirmation of the cyst reabsorption[6,18]. Other two early clinical improvement were described, but radiological resolution was achieved after over one year[16,19]. Generally, clinical improvement and radiological remission occurred on average respectively in 7 and 11 mo.

CONCLUSION

The natural history of spinal ganglion cysts is unknown and there is scant literature involving their non-surgical therapy. In the lumbar spine, different degrees of biomechanical impairment seem to play a fundamental role in their pathogenesis, but LGCs should be considered as dynamic entities. In other words, formation and resolution appear strictly influenced by event and regression of inflammatory and mechanical phenomena.

Although rarely, the symptoms related to LGC, essentially represented by low back and/or radicular pain, could regress spontaneously, if cystic evolution (enlargement, hemorrhage, worsening of spondylolisthesis) with associated worsening of neurological status does not occur.

Our case is the twenty-sixth in literature. Based on our experience and reviewing data, we can suggest that in case of absence of neurological deficits and in selected compliant patients, percutaneous procedures or surgery should be considered when conservative treatment, consisting of rest, pharmacological therapy, kinesiotherapy and/or lumbar bracing, prolonged at least for 6 mo, fails to produce symptoms control. We recommend, anti-inflammatory drugs and light unloading exercises to control pain and reduce intra-cystic fluid, but also rest and lumbar bracing to achieve the decrease of loads on arthritic facets. We also recommend MRI confirmation of cyst resolution, which can be helpful to understand mechanisms responsible of resolution.