Takuma Hara, Hiroyoshi Akutsu, Shingo Takano, Hiroyoshi Kino, Eiichi Ishikawa, Shuho Tanaka, Hidetaka Miyamoto, Noriaki Sakamoto, Keiichiro Hattori, Mamiko Sakata-Yanagimoto, Shigeru Chiba, Takashi Hiyama, Tomohiko Masumoto and Akira Matsumura
The Wnt/β-catenin signaling pathway is strongly implicated in the pathogenesis of adamantinomatous craniopharyngioma (adaCP). However, there is no evidence that the CTNNB1 mutation activates the target gene of Wnt/β-catenin signaling, and it is unknown whether it affects the tumorigenesis of adaCP. To assess the effect of the CTNNB1 mutation of adaCP, the authors analyzed the correlation between the mutation and clinical, radiological, pathological, and biological findings.
Between 2003 and 2015, 42 patients (24 male and 18 female, median age 42 years) with either papillary craniopharyngioma (papCP) or adaCP underwent tumor resection at the authors’ institution. BRAF V600E and CTNNB1 in papCP and adaCP samples were sequenced by next-generation sequencing and the Sanger method, and mRNA expression levels of Axin2 and BMP4 were evaluated by RT-PCR. Axin2, BMP4, β-catenin, and BRAF expression were evaluated by immunohistochemistry. Other data were collected from clinical reports.
The BRAF V600E mutation was detected in all 10 cases of papCP (100%). CTNNB1 exon 3 mutations were detected in 21 of 31 (68%) cases of adaCP, excluding 1 case for which there were no available sequence data. The mRNA expression level of Axin2 was significantly higher in adaCPs with a CTNNB1 mutation than in those without (p < 0.05). The immunohistochemical findings of Axin2 and BMP4 did not correlate with CTNNB1 mutation positivity. When patients who received adjuvant radiation therapy were excluded, progression-free survival was shorter in the mutation-positive group than in the mutation-negative group (log-rank test, p = 0.031). Examination of clinical characteristics and immunohistochemical findings of adaCPs showed that there was no significant correlation between CTNNB1 mutation positivity and age, sex, tumor volume, gross-total resection, optic tract edema, calcification, or T1 signal intensity of cyst fluid on MRI, β-catenin, and MIB-1 index.
These results raise the possibility that the CTNNB1 mutation in adaCP may be associated with disease recurrence, and genes related to the Wnt/β-catenin signaling pathway might represent a therapeutic target.
Hiroyoshi Kino, Hiroyoshi Akutsu, Shuho Tanaka, Takuma Hara, Hidetaka Miyamoto, Noriaki Sakamoto, Shingo Takano, Tomohiko Masumoto, Masanari Shiigai, Eiichi Ishikawa and Akira Matsumura
Rathke’s cleft cyst (RCC) is a benign cystic lesion with a relatively high incidence of local recurrence that occasionally requires repeat surgery. To prevent recurrence, simple cyst fenestration and drainage of the cyst contents to the sphenoid sinus is recommended, but it occasionally recurs. The authors postulated that obstruction of fenestration is a main cause of recurrence, and they developed a method, named the “mucosa coupling method (MC method),” that maintains persistent drainage. In this method, the RCC epithelium and the mucosa of the sphenoid sinus are connected, which promotes re-epithelialization between the two epithelia, maintaining persistent drainage. The outcome of this method was compared with that of conventional cyst fenestration.
In a consecutive series of 40 patients with RCC, the surgical strategy was changed during the study period: from December 2009 to September 2014 (the conventional period), 24 patients were scheduled to be treated using the conventional fenestration method, whereas from September 2014 to September 2017 (the MC period), 16 patients were scheduled to be treated using the MC method. However, because of an intraoperative CSF leak, the fenestration was closed during surgery in 3 patients in the conventional period and 2 in the MC period; therefore, these 5 patients were excluded from the analysis. Twenty-one patients treated with the conventional fenestration method (conventional group) and 14 patients treated with the MC method (MC group) were analyzed. All patients regularly underwent MRI after surgery to detect reaccumulation of cyst contents. The rate of reaccumulation with and without reoperation, visual outcomes, endocrinological outcomes, and postoperative complications were compared between these two groups.
The median follow-up period in all 35 patients was 48.0 months (range 1–96 months), 54.0 months (range 1–96 months) in the conventional group and 35.5 months (range 12–51 months) in the MC group. No reaccumulation was detected on MRI in the 14 patients in the MC group, whereas it was noted in 9 (42.9%) of 21 patients in the conventional group, and 2 of these 9 patients required repeat surgery. There were no significant differences in visual and endocrinological outcomes and complications between these two groups.
The MC method for RCC is effective for preventing obstruction of cyst fenestration, which contributes to preventing cyst reaccumulation. Furthermore, this method is equivalent to the conventional fenestration method in terms of visual and endocrinological outcomes and the complication rate.