Spontaneous Involution of a Rathke Cleft Cyst

MRI-Based Classification of Rathke's Cleft Cyst and Its Clinical Implication

BACKGROUND

Rathke's cleft cysts (RCCs) are benign tumors of the pituitary gland. Small, asymptomatic RCCs do not require surgical treatment, whereas surgical treatment is required for symptomatic RCCs.

METHODS

We retrospectively reviewed medical records of patients with an RCC who were diagnosed and managed in our institution between April 2004 and April 2020 and generated two different cohorts: the observation (n=114) and the surgical group (n=99). Their initial MRI signal characteristics were analyzed. The natural course focusing on cyst size was observed in the observation group and postoperative visual and endocrine outcomes were evaluated in the surgical group.

RESULTS

The characterization of MRI signals of cyst contents in both T1-weighted (T1W) and T2-weighted (T2W) images revealed nine combinations for our 213 patients. Among 115 patients with a high T2W signal, the cysts showed hypo-, iso-, and hyper-intensity on T1W images in 72, 39, and 44 patients, respectively; Type S-low, Type S-iso, and Type S-high. One more major group of 35 patients showed RCCs with hyperintensity on the T1W images and hypointensity on the T2W images named as Type M. In the comparison between observation and surgical groups, we identified only two major groups in which the number of patients in the surgical and observation groups was statistically different: more Type S-low in a surgical group (p<0.001) and more Type M in an observation group (p=0.007). In subgroup analysis, the range of change in the cyst size was the highest in Type S-high in the observation group (p=0.028), and intergroup differences in visual and endocrine outcomes were not evident in the surgical group.

CONCLUSION

MRI characteristics help to predict the natural course of RCCs. We identified subgroups of RCCs which are more or less likely to require surgical intervention.

Natural course of Rathke's cleft cysts and risk factors for progression

OBJECTIVE

Rathke's cleft cysts (RCCs) are relatively common and often detected incidentally. They are usually asymptomatic and managed conservatively. However, little is known about their natural history. Thus, the authors aimed to examine the natural course of RCCs and identify the risk factors for their progression.

METHODS

This retrospective study examined 229 patients (median age 43.0 years) diagnosed with RCCs by MRI and followed up without surgery (median period 36.6 months). The median cyst height on the initial MRI was 10 mm. Progression or regression of RCC was defined as cyst height changes of ≥ 1 mm.

RESULTS

In total, 23 (10.0%) RCCs progressed, whereas 73 (31.9%) RCCs spontaneously regressed. The remaining 133 were noted to be stable throughout the follow-up period. Patients with progressed RCCs were significantly older than those with stable RCCs. In patients with acute headache as an initial symptom, RCCs were significantly more likely to spontaneously regress. New symptoms occurred in 6 patients, 5 of whom underwent surgery for RCC progression. Of these 6 patients, 1 patient had persistent adrenocorticotropic hormone deficiency and 1 patient developed diabetes insipidus. Kaplan-Meier analysis results showed RCC progression and new symptom development rates to be 12.0% and 4.1% at 5 years and 13.7% and 5.7% at 10 years, respectively.

CONCLUSIONS

RCCs rarely progress or cause new symptoms in the long term. Patients with asymptomatic RCC should be followed up for at least 5 years to ensure RCC inactivity. RCCs in older adults may require greater surveillance.

Spontaneously Regressed Rathke's Cleft Cyst

We report two rare cases of spontaneously regressed Rathke's cleft cyst (RCC). A 52-year-old woman presented with headache. A pituitary hormone study was normal. Brain magnetic resonance imaging (MRI) showed a 0.45-cm3 cystic sellar lesion. The cyst was hyperintense on T1-weighed imaging and hypointense on T2-weighted imaging without rim enhancement, comparable to a RCC. Six months later, brain MRI showed no change in the cyst size. Without any medical treatments, brain MRI 1 year later revealed a spontaneous decrease in cyst volume to 0.05 cm3. A 34-year-old woman presented with headache and galactorrhea lasting 1 week. At the time of the visit, the patient's headache had disappeared. Her initial serum prolactin level was 81.1 ng/mL, and after 1 week without the cold medicine, the serum prolactin level normalized to 11.28 ng/mL. Brain MRI showed a RCC measuring 0.71 cm³. Without further treatments, brain computed tomography 6 months later showed a spontaneous decrease in cyst volume to 0.07 cm³. Another 6 months later, brain MRI revealed that the cyst had remained the same size. Neither patient experienced neurological symptoms, such as headache or visual disturbance, during the period of cyst reduction. The RCCs in both patients underwent spontaneous regression without any medical treatment during a period of 6 months to 1 year. Although spontaneous regression of a RCC is rare, it is still possible and a sufficient follow-up period should be considered.

Natural history of Rathke's cleft cysts: A retrospective analysis of a two centres experience

OBJECTIVE

Rathke's cleft cyst (RCC) is a common sellar lesion which may cause visual impairment, hypopituitarism and headaches from mass effect. The natural history of these lesions is currently unclear. We investigated the natural history of RCCs and compared surgically treated patients with those treated conservatively.

METHODS

We performed a retrospective cohort study of patients diagnosed with a RCC between 1996 and 2016 at Stanford University and Ospedale Maggiore Policlinico di Milano.

RESULTS

Patients were divided into 2 cohorts: Group A, 72 subjects who underwent surgical resection of a symptomatic RCC, and Group B, 62 subjects managed conservatively. Compared to Group B, Group A subjects had larger RCCs (79% vs 22% had a largest diameter >10 mm, P < .001) and were more likely (41.5% vs 16%, P < .001) to present with hypopituitarism and diabetes insipidus (DI) (18% vs 1.6%, P = .002). In Group A, after a mean follow-up of 53.7 months, 12.5% of patients had recurrence and a second surgery. After surgery, 35% of patients recovered pituitary function. Hyperprolactinemia (26.6%) and hypogonadism (66.6%) resolved more commonly that did DI (20.1%). New pituitary deficits appeared in 16.6% of patients after surgery. In Group B, with a mean follow-up of 41 months, only 6.4% had cyst enlargement, none underwent surgery, and none developed a pituitary deficit.

CONCLUSION

Our data offer guidance in decision-making regarding the management of RCC patients and confirm the safety of conservative treatment in asymptomatic patients.