Cerebral tumor embolism from thyroid cancer treated by mechanical thrombectomy: illustrative case.

BACKGROUND: Development in mechanical thrombectomy is progressing dramatically. Tumor embolism has been rarely reported on the basis of pathological study of the retrieved thrombus. Herein, the authors report a case of cerebral tumor embolism from advanced thyroid cancer, which was successfully treated with mechanical thrombectomy. OBSERVATIONS: A 57-year-old man was diagnosed with thyroid cancer with multiple lung metastases and chemotherapy was planned. He experienced left hemiparesis and was bought to the emergency section of the authors' hospital. Magnetic resonance angiography revealed right internal carotid artery occlusion and endovascular treatment was performed. Using a combination of aspiration catheter and stent retriever, white jelly-like embolus was retrieved. The pathological study demonstrated thyroid cancer embolism. Pulmonary vein invasion following lung metastasis of thyroid cancer was most presumably the cause of the tumor embolism. LESSONS: Lung metastasis invading the pulmonary vein may be a cause of tumor embolism. Mechanical thrombectomy using a combination of stent retriever and aspiration catheter is effective in removing the tumor embolus and the pathological examination of the embolus is essential.

Factors associated with the location of perivascular space enlargement in middle-aged individuals undergoing brain screening in Japan.

OBJECTIVE: In elderly populations, the enlargement of the perivascular space is related to small vessel disease and the glymphatic system. Enlarged perivascular spaces (EPVS) in the basal ganglia (EPVS-BG) and EPVS in the centrum semiovale (EPVS-CSO) are associated with different pathophysiological processes. However, the prevalence of EPVS and the factors associated with EPVS location in healthy middle-aged individuals are still unclear. We aimed to determine the prevalence of EPVS and the factors associated with EPVS location among healthy individuals in their 40 s METHODS: This study included 5000 consecutive healthy individuals who underwent screening for brain diseases in Japan from August to December 2018. Of them, the data of individuals in their 40 s were extracted and analyzed. The associations of age, sex, body mass index, smoking and drinking history, and medical history with EPVS location were investigated. Similar analyses were performed for the other age groups. A literature review on the factors associated with EPVS location was also performed. RESULTS: A total of 1720 individuals in their 40 s were finally included. The prevalence of EPVS-BG and EPVS-CSO was 7.7% and 9.2%, respectively. Age (years), smoking history, and hypertension were associated with EPVS-BG; none of the studied factors were found to be associated with EPVS-CSO. In the elderly, the factors previously reported to be associated with EPVS-BG included atherosclerosis change, while the factors associated with EPVS-CSO were cerebral amyloid angiopathy-related formation. CONCLUSION: Both EPVS-BG and EPVS-CSO occurred among healthy individuals in their 40 s, but they did so rarely, and less prevalently than in older age groups. EPVS-BG and EPVS-CSO may represent early imaging signs of the atherosclerotic and cerebral amyloid angiopathy processes, respectively. DATA AVAILABILITY: The anonymized data for this study will be shared upon any qualified investigator's request to the corresponding author. Primary data from this study will be made available upon reasonable request in accordance with the review board of the research institute.

Recent Declining Trend of Incidence Rate of Subarachnoid Hemorrhage in Shimane, Japan: The Japan Incidence of Subarachnoid Hemorrhage (JIS) Study.

The "Izumo Study" revealed the incidence rate of subarachnoid hemorrhage (SAH) in Izumo City, Shimane Prefecture, Japan, from 1980 to 1998. However, no study has been published regarding the incidence of SAH in Shimane Prefecture after 1998. Most studies reporting the incidence of SAH in Japan have been conducted before 2000, although a few have been reported after 2000. This study aimed to assess the estimated age-adjusted incidence rate (AAIR) of SAH in Shimane Prefecture after 1998, following the Izumo Study. A retrospective study was conducted to identify the estimated AAIR of SAH in Shimane Prefecture, using the age-adjusted SAH mortality rate for this population from 1999 to 2017 and assuming that the case-fatality rate of SAH decreased by 0.7% annually from 45% in 1999 to 32.4% in 2017. We used linear regression analysis for trend to the estimated AAIR of SAH. Sensitivity analyses were also conducted by various case-fatality rates of SAH using assuming case-fatality rate based on previous reports. The estimated AAIR of SAH in Shimane Prefecture declined from 33.6 (95% confidence interval [CI]: 29.7-37.9) per 100,000 person-years in 1999, by 26.5%, to 24.7 (95% CI: 21.4-28.5) in 2017 (p < 0.01, r = 0.58). Declining trend of incidence rate of SAH in Shimane Prefecture from 1999 to 2017 was confirmed in this study.

Metastatic Brain Tumor in the Cerebellopontine Angle from Gastric Cancer: A Case Report.

Cerebellopontine angle (CPA) tumors are a common type of benign tumors, which are similar to vestibular schwannomas; however, the incidence of CPA metastasis is rare. Moreover, brain metastasis from gastric tumors is a rare occurrence, with an incidence of less than 1% in clinical cases. In this study, we report the case of a 71-year-old man who was admitted to our hospital with symptoms of nausea and gait instability for the past 1 week. He had no remarkable medical history. Magnetic resonance imaging revealed a tumor in the left CPA. Intraoperative diagnosis indicated the presence of metastatic papillary carcinoma. Postoperatively, gastric endoscopy revealed a protruding mass on the cardia of the stomach, which was histopathologically similar to that of the resected brain tumor. The patient underwent adjuvant cyberknife radiotherapy and chemotherapy. A prompt biopsy of the brain tumor is essential if any findings suggest malignancy.

Frameless Free-Hand Navigation-Guided Biopsy for Brain Tumors: A Simpler Method with an Endoscope Holder.

CONTEXT/AIMS: Given the limitations of current navigation-guided brain biopsy methods, we aimed to introduce a novel method and validate its safety and accuracy. SETTING AND DESIGN: This was a retrospective study of twenty consecutive patients who underwent brain biopsy at Shimane University Hospital, Japan. SUBJECTS AND METHODS: Clinical records of 13 and 7 patients who underwent brain biopsy with the novel frameless free-hand navigation-guided biopsy (FFNB) method or a framed computed tomography-guided stereotactic biopsy (CTGB) method, respectively, were retrospectively reviewed. We compared age, sex, tumor location, histological diagnosis, maximum size of the tumor (target), depth from target to cortical surface on the same slice of CT or magnetic resonance imaging, operative position, anesthesia method, setup time for biopsy, incision-to-closure time, trial times for puncture, success rate, and complications in the two groups. STATISTICAL ANALYSIS: Fisher's exact test and the Wilcoxon rank-sum test were performed. RESULTS: Clinical characteristics and lesion size did not differ significantly between the FFNB and CTGB groups. The depth of the target lesion was significantly greater in the CTGB group (P < 0.05). All FFNB and CTGB procedures reached and obtained the target tissue. The number of punctures and the average incision-to-closure time did not differ between the FFNB and CTGB groups. However, the preoperative setup time was significantly shorter using FFNB (P = 0.0003). No complications were observed in either group. CONCLUSIONS: FFNB was comparable with CTGB in terms of safety, accuracy, and operative duration. The preoperative setup time was shorter using FFNB. Therefore, FFNB is a feasible method for brain tumor biopsy.

Takotsubo cardiomyopathy following mechanical thrombectomy for acute ischemic stroke: illustrative case.

BACKGROUND: Excess neurological stress by hemorrhagic stoke induces cardiomyopathy, namely takotsubo cardiomyopathy. Here, the authors report a case of takotsubo myopathy following mechanical thrombectomy for acute large vessel occlusion. OBSERVATIONS: A 73-year-old man was emergently brought to the authors' hospital because of left hemiparesis and consciousness disturbance. An ischemic lesion of the right cerebral hemisphere and the right internal carotid artery occlusion was revealed. Emergently, endovascular treatment was performed, and occlusion of the artery was reanalyzed. However, he suffered from hypotension with electrocardiogram abnormality. Subsequently, coronary angiography was performed, but the arteries were patent. The authors made a diagnosis of takotsubo cardiomyopathy. LESSONS: Endovascular recanalization for large cerebral artery occlusion is so effective that it is becoming widely used. Even in the successful recanalization, we need to care for the takotsubo cardiomyopathy.

Aggressive Intraoperative Cisternal Clot Removal After Clipping Aneurismal Subarachnoid Hemorrhage in Elderly Patients.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (aSAH) in the elderly often has a poor prognosis even after surgical treatment in the acute phase. Additionally, subarachnoid clots are the strongest predictors of cerebral vasospasm and tend to be thicker and heavier due to cerebral atrophy. We aimed to compare the conventional surgical treatment in such patients and identify the independent predictors of a favorable outcome after aggressive surgical clot removal. METHODS: We included 40 patients with aSAH aged 70 or older. Each patient underwent aneurysmal clipping. We used the modified Rankin Scale to assess the primary outcome of neurologic status at discharge. We performed univariate analysis using the following factors: sex, age, neurologic, and general medical condition, radiographic data, aneurysm location, treatment approach, and timing of the aneurysm surgery. We divided the patients into irrigation and nonirrigation groups. We focused mainly on subarachnoid clots and analyzed them semiquantitatively using computed tomography. RESULTS: Clot removal was significantly greater in the irrigation group (n = 21) than in the nonirrigation group (n = 19). The period of intrathecal drainage was significantly shorter in the irrigation group (P = 0.002). The rate of occurrence of new low-density areas on CT scans was higher in the nonirrigation group. Outcomes were better in the irrigation group (P = 0.010). CONCLUSIONS: In elderly patients with aSAH in the acute phase, aggressive surgical clot removal after clipping showed favorable outcomes by facilitating early out-of-bed mobilization.

Aging Changes of Aneurysmal Subarachnoid Hemorrhage: A 35-year, Hospital-Based Study.

BACKGROUND: The etiology and background factors which cause decreases in the size of ruptured intracranial aneurysms remain unclear. OBJECTIVE: To clarify the age- and sex-related differences in aneurysmal subarachnoid hemorrhage (SAH) based on a 35-year-old hospital database and demographic data. METHODS: A database of patients admitted to our hospital with aneurysmal SAH from 1983 to 2017 was split into 5-year intervals and analyzed. Demographic data of the general population were also analyzed for reference. RESULTS: Altogether, 1,523 aneurysmal SAH events were enrolled in the analysis. Age (p<0.001), proportion of elderly patients ≥ 65 years old (p<0.001), female sex (p=0.005), very small aneurysms less than 5 mm (p<0.001), and the yearly-averaged number of fatal events showed increasing trends. The proportion of aneurysm size of 10 mm or more (p = 0.011) and the yearly-averaged population of Shimane prefecture (p < 0.001) showed declining trends. In the subgroup analyses, the proportion of very small aneurysms was found to increase significantly in the non-elderly male and elderly female subgroups. The proportion of large aneurysms (10 mm or more) decreased in the non-elderly subgroup (p<0.05). As for the elderly subgroups, the yearly-averaged number of events did not show a significant tendency, although the yearly-averaged population of Shimane prefecture showed an increasing trend. CONCLUSION: We found an increasing trend in the prevalence of very small aneurysms in elderly females. Recent aging may contribute to this trend. The number of aneurysmal SAH events was confirmed to not increase, despite the increased aging population of Shimane prefecture.

Propensity Score Matching Analysis for the Patients of Unruptured Cerebral Aneurysm from a Post Hoc Analysis of a Nationwide Database in Japan.

BACKGROUND: This study aimed to compare the functional outcome at discharge for unruptured cerebral aneurysms (UCAs) between surgical clipping and endovascular coiling in total, nonelderly (<65 years), and elderly (≥65 years) patients by nonbiased analysis based on a national database in Japan. METHODS: A total of 15,671 patients with UCA were registered in the Diagnosis Procedure Combination, the nationwide database, from 2010 to 2015 in Japan. The outcome of the Barthel Index (BI) at discharge was investigated, and propensity score-matched analysis was conducted in total, nonelderly, and elderly patient groups. RESULTS: Propensity score-matched analysis found no significant difference for in-hospital mortality between the 2 treatment methods in the total and both age-groups. The rate of morbidity of BI <90 at discharge was higher after surgical clipping than after endovascular coiling in the total (4.9% vs. 3.9%; P = 0.040; risk difference, -1.0%; 95% confidence interval, -3.6 to 2.3%) and the elderly age-group (8.1% vs. 5.0%; P < 0.001; risk difference, -3.1%; -4.8% to 1.5%), however, no significant association between the 2 treatment methods (2.4% vs. 2.6%; P = 0.67; risk difference, 0.22%; -0.79 to 1.22%) was found in the nonelderly group. CONCLUSIONS: In elderly patients with UCA, a better outcome at discharge after endovascular coiling was found. However, no significantly different functional outcome at discharge between surgical clipping and endovascular coiling for UCA in nonelderly patients was confirmed by propensity score-matched analysis from a nationwide database in Japan.

Risk Management of Aneurysmal Subarachnoid Hemorrhage by Age and Treatment Method from a Nationwide Database in Japan.

OBJECTIVE: There has been no precise guide for treatment management of aneurysmal subarachnoid hemorrhage (aSAH) based on the patient's age and treatment method. This study clarifies each risk management for aSAH according to age and treatment method listed in a nationwide database. METHODS: We compared 2 groups of patients (nonelderly, <65 years; elderly, ≥65 years) who underwent surgical clipping or endovascular coiling and were registered in a nationwide database in Japan from 2010 to 2015. The odds ratio (OR) and 95% confidence interval (CI) of each risk factor were calculated through multivariate logistic regression analysis for poor outcome according to a modified Rankin Scale score >2 at discharge for each group. RESULTS: In all groups, the risk factors for poor outcome were older age, male sex, neurologic grade on admission, diabetes mellitus, and use of anticoagulation drugs. Inverse risk factors were a high-volume hospital, academic hospital, hypertension, and use of an antiplatelet drug (OR, 0.63-0.81; 95% CI, 0.56-0.88). Chronic heart disease was also a risk factor, but use of a statin drug (OR, 0.85-0.87; 95% CI, 0.76-0.97) and location other than on the anterior communicating artery (OR, 0.74-0.80; 95% CI, 0.67-0.91) were inverse risks in both the elderly and the endovascular coiling groups. CONCLUSIONS: Management for patients with aneurysmal subarachnoid hemorrhage was recommended in high-volume and academic institutes with the administration of antiplatelet drugs and consideration of several risk factors. Elderly patients undergoing endovascular coiling might be better given a statin drug, and patients with chronic heart failure or an anterior communicating artery aneurysm should be treated more carefully.

Treatment Risk for Elderly Patients with Unruptured Cerebral Aneurysm from a Nationwide Database in Japan.

BACKGROUND: This study aimed to clarify the risk factors of treatment for unruptured cerebral aneurysms (UCAs) in elderly patients by comparing the morbidity at discharge between surgical clipping and endovascular coiling in nonelderly (<65 years) and elderly (≥65 years) patients based on a national database in Japan. METHODS: A total of 36,017, including 15,671 patients with UCA after exclusion of unknown location, were registered in the Diagnosis Procedure Combination, the nationwide database, from 2010 to 2015 in Japan. Outcome of Barthel Index at discharge was investigated and multivariate logistic regression analysis identified risk factors for morbidity of Barthel Index <90 at discharge in nonelderly and elderly patient groups. RESULTS: Risk factors for morbidity at discharge were basilar artery aneurysm compared with internal carotid artery (ICA), diabetes mellitus (odds ratio [OR], 2.0-2.5; 95% confidence interval [CI], 1.6-3.7), antiplatelet drug, and anticoagulation drug; however, highest hospital volume compared with lowest was an inverse risk factor in both age groups. Endovascular coiling (OR, 0.4; 95% CI, 0.3-0.5) was a significantly inverse risk in the elderly group. Anterior communicating artery aneurysm compared with ICA was a significant risk (OR, 1.6; 95% CI, 1.0-2.6) in the nonelderly group; on the other hand, anterior communicating artery aneurysm (OR, 0.7; 95% CI, 0.5-0.95) and middle cerebral artery aneurysm (OR, 0.6; 95% CI, 0.5-0.8) compared with ICA were significantly inverse risks in the elderly group. CONCLUSIONS: Endovascular coiling after control of diabetes mellitus was recommended for the treatment of UCA in elderly patients. The ICA location of aneurysm in the elderly should be paid attention as the treatment risk.

Fatal Postpartum Hemorrhage in Diffuse Midline Glioma with H3-K27M Mutation.

Management of pregnant women with brain tumors necessitates difficult decision-making especially for estimating or preventing its intratumoral hemorrhage. A 26-year-old, 19-week pregnant woman complaining of headache and vomiting was admitted to our hospital. Magnetic resonance imaging (MRI) revealed hydrocephalus and a mass lesion without contrast enhancement extending from the left thalamus. To resolve severe symptoms, a ventriculoperitoneal shunt was inserted, and a biopsy was taken via the right ventricle. Pathological examination suggested diffuse or pilocytic astrocytoma, but subsequent genetic analysis revealed the diagnosis of midline glioma with H3-K27M mutation. The patient opted not to terminate the pregnancy, and MRIs conducted every four weeks revealed no change in tumor aspect. The patient delivered a healthy baby by cesarean section, and postpartum day 1 was uneventful. However, she was found in a coma due to a massive intratumoral hemorrhage on postpartum day 2 and died 3 weeks after the hemorrhage. This is the first case report of diffuse midline glioma with H3-K27M mutation in a pregnant woman followed by fatal hemorrhage. It highlights the necessity of careful clinical management and frequent neuroimaging during the entire perinatal period, even if the tumor has hypovascularity or low proliferative potential on radiological or pathological findings.

Ten-Year Follow-Up of Collision Tumors Composed of Craniopharyngioma and Pituitary Adenoma: A Case Report and Literature Review.

Although craniopharyngioma (CP) and pituitary adenoma (PA) are common tumors of the parasellar lesions, the coexistence of CP and PA is very rare. A 48-year-old male visited our hospital because of consciousness disturbance. The neuroimaging revealed a sellar tumor contact with a massive suprasellar cyst including calcification. Preoperative diagnosis was CP, and the patient underwent craniotomy to resolve the suprasellar mass effect. The histological examination disclosed adamantinomatous CP, and subsequently a transsphenoidal approach was chosen for the residual intrasellar tumor. Against expectations, the histological diagnosis was not CP but PA. The patient underwent gamma knife surgery for the residual tumor, and the postoperative course was good. After a 10-year follow-up, both lesions were still completely controlled. If we had suspected and diagnosed the tumor involved as not only CP but also PA at the first operation, the second operation could have been avoided because we would have chosen gamma knife surgery for the residual tumor. We should draw attention to this rare situation for differential diagnosis of parasellar tumor to avoid unnecessary surgery and to decide the best strategy for treatment. In addition, the biological behavior of collision tumors composed of CP and PA is probably the same as solitary CP or PA based on a long-term follow-up of our case.

[A Case of Metastatic Peripheral T-cell Lymphoma of the Central Nervous System During the Perinatal Period].

The diagnosis of malignant tumors during pregnancy is not uncommon; the incidence is one per six thousand pregnancies. However, the diagnosis of malignant lymphoma-especially T-cell lymphoma-during pregnancy is extremely rare. Thus, the early detection and management of T-cell lymphoma necessitates difficult decision-making. A 30-year-old woman developed consciousness disturbance on postpartum day three. Because brain MRI showed multiple edematous lesions in both hemispheres, vasculitis or encephalitis was initially suspected, and diagnostic therapy was initiated with the administration of steroids. One month later, the patient suddenly developed a subarachnoid hemorrhage followed by acute hydrocephalus. Emergent ventricular drainage and lesion biopsy were simultaneously performed. Based on the findings, the patient was diagnosed with peripheral T-cell lymphoma not otherwise specified(PTCL-NOS). Laboratory findings indicated Epstein-Barr virus(EBV)infection. Moreover, the same diagnosis was supported by breast and bone marrow biopsies. Thus, the brain lesions were presumed to be metastatic in nature. The prognosis of PTCL-NOS is severely poor in pregnant women as diagnosis is delayed owing to limitations of radiological examinations and because symptoms can be confused with those of other diseases or hyperemesis gravidarum. Additionally, the alteration of immunotolerance in association with pregnancy and EBV infection might have influenced the aggressive features of this case. When a pregnant woman presents with neurological symptoms, malignant lymphoma should be considered when making a differential diagnosis.

Pyothorax-associated Angiosarcoma Metastasized to the Brain with Multiple and Progressively Expanding Hematomas: Case Report and Literature Review.

The brain metastasis of angiosarcoma is very rare, and little is known about its clinical features or therapeutic strategy. A 74-year-old male was hospitalized for disturbance of consciousness. Radiological examination revealed multiple cerebral hematomas. Gadolinium contrast-enhanced magnetic resonance imaging showed no significant enhancement at any of the lesions. To detect a suspected metastatic brain tumor or abscess, a full-body scan was performed but revealed only a poorly enhanced mass in the removal cavity caused by thoracoplasty in the left upper chest. After admission, a cascade of expansion of those hematomas occurred in the right frontal, left parietal, and right temporal lobes, and each lesion thus had to be sequentially removed by craniotomies. The pathological diagnosis of the right frontal lesion was an abscess with hematoma. However, a malignant vascular tumor was highly suspected because of many CD31(+)/Ki-67(+) cells in the left parietal lesion. A mass in the scar caused by thoracoplasty was suspected to be the primary lesion, and brain metastasis of angiosarcoma was finally diagnosed. Whole-brain irradiation and systemic paclitaxel administration were performed, and a complete response for the brain lesions was obtained for 22 months; the patient then died of an intratracheal hemorrhage. This case represents the first report of multiple brain metastases from pyothorax-associated angiosarcoma accompanied by sequentially and gradually expanding hematomas, as well as the first case with the control of metastatic brain lesions for over 1 year after the onset of neurological symptoms. Control of the lesions could be achieved by their total removal with complete hemostasis, as well as additional radio- and chemotherapy.

A Case of De Novo Anterior Condylar Dural Arteriovenous Fistula Long after Curative Transvenous Embolization of Contralateral Anterior Condylar Arteriovenous Fistula.

We report on a 55-year-old man who developed a de novo DAVF in left ACC 5 years after curative transvenous embolization for DAVF in right ACC. Angiography revealed that the de novo lesion demonstrated more aggressive arteriovenous shunt flow than the initial lesion. Successful transvenous embolization was performed for also the second lesion. The authors describe the possible pathophysiological mechanisms and management strategies for this rare occurrence.

[A case of repeated shunt malfunctions with eosinophilic meningitis caused by silicone allergy].

The ventricular-peritoneal shunt for hydrocephalus is a well-known and established method but is sometimes complicated by shunt malfunction due to several causes. Eosinophilic meningitis is a rare disease, but has occasionally been reported as a cause of shunt malfunction. Here, we report the case of a 74-year-old woman with repeated shunt malfunction and eosinophilic meningitis due to a silicone allergy. Originally, the patient received a ventricular-peritoneal shunt for normal pressure hydrocephalus secondary to subarachnoid hemorrhage. However, shunt malfunction was identified 6 weeks later, and the first shunt revision was performed using a new shunt system from a different company. Further evaluation to identify the cause of the shunt malfunction revealed no abnormal findings, except for eosinophilia in the serum and cerebrospinal fluid. A second shunt malfunction was identified 16 weeks after the first shunt revision. We therefore concluded that eosinophilic meningitis caused by a silicone allergy might be the real culprit and a second shunt revision was performed using a silicone "extracted" tube. Since then, the patient's course has been free from shunt malfunction. In this case, the serum and cerebrospinal fluid eosinophilia were useful markers for identifying the cause of repeated shunt malfunctions. The silicone "extracted" tube may be helpful for diagnosis and therapy.

Primary brain abscess caused by Nocardia otitidiscaviarum.

Diagnosing primary cerebral nocardiosis is difficult. This case report describes a 79-year-old immunocompetent Japanese woman with a primary brain abscess caused by Nocardia otitidiscaviarum (IFM 11321) and reviews the findings of 11 previous patients with N. otitidiscaviarum-induced brain abscesses. Four patients survived, including ours. Beta-lactams were not effective in our patient, and the diagnosis required a pathologic analysis of the surgical specimen. Sulfamethoxazole/trimethoprim (ST) was administered to the patient. On antibiotic susceptibility testing, N. otitidiscaviarum (IFM11321) was found to be resistant to amoxicillin-clavulanic acid, ceftriaxone, cefotaxime, cefepime, imipenem and clarithromycin, but sensitive to amikacin, gentamicin, ST and linezolid. Antimicrobial susceptibility patterns differ among Nocardia species, making species identification important for treatment. Patients with suspected Nocardia infection should therefore be treated empirically with ST and/or amikacin and considered for surgical management.

Rathke's cleft cyst with non-hemorrhagic rupture resulting in alteration of signal intensity for a short period: a case report.

In a case of 23-year-old female with Rathke's cleft cyst (RCC), unusual changes with size and morphology on computed tomography (CT) and magnetic resonance images (MRI) were noted in a short period of 3 weeks after spontaneous rupture. The CT noted that the intracystic isodensity was changed to hyperdensity. And MRI showed not only a decrease in size of the lesion but also changing from hypo- and hyperintensity in T1- and T2-weighted images to hyperintensity in both T1- and T2-weighted images. The intraoperative findings disclosed that the cyst content was milky-like, but not hemorrhagic. We considered that the leakage of cyst content to the cerebrospinal fluid pathway caused not only inflammatory reaction but also waxing and waning of both the cyst size and intralesional protein concentration, which resulted in unusual changing CT and MR appearance. We should take into consideration that the nature of RCC can be altered by not only intracystic hemorrhage but also non-hemorrhagic rupture even for a short period.