No abstract

Among intracranial cystic lesions, dermoid cysts and epidermoid cysts are relatively common benign tumors. In a small number of these tumors, it is known that squamous cell carcinomas arise in the lining epithelium of the cysts. Among tumors derived from the appendage, only one case of hidradenoma within a dermoid cyst and no cases of sebaceous tumor have been reported previously. In the present case, a protruding lesion was present in the cystic wall, and it was composed of two cell types: sebaceous cells (sebocytes) and basaloid/germinated cells, being characteristic of this tumor. It is essential to distinguish it from other sebaceous lesions such as hyperplasia, sebaceoma, sebaceous carcinoma, and basal cell carcinoma with sebaceous differentiation derived from the epidermis. The critical distinguishing points in making a differential diagnosis among these lesions are the ratio of the two cell types and the presence or absence of other components such as hair sacs, invasion or cellular atypia. Immunohistochemical examination revealed that the tumor cells were positive for the epithelial markers, such as cytokeratin (CK)14, p63, p40, high‐molecular CK, and adipophilin; these findings are peculiar to sebaceous adenoma. Although there have been several similar case reports of sebaceous tumors associated with dermmoid cysts in the ovaries, most of the intracranial lesions were squamous cell carcinomas that developed within the cysts, and there has been no precedent showing an association with a sebaceous tumor. The present report describes the first case of sebaceous adenoma that occurred in an intracranial dermoid cyst.

Background: A patient presented with a spinal subarachnoid hemorrhage (SAH) and subdural hematoma (SDH) attributed to a spinal schwannoma at the T12-L1 level. Case Description: A 67-year-old male acutely presented with severe back pain and L1 paraparesis/sensory loss, with urinary incontinence. CT/MR studies showed a spinal SAH and SDH within a likely T12-L1 schwannoma. At surgery, the hemorrhage within the tumor was continuous through the lower pole of the tumor into the subarachnoid and subdural spaces; tumor was dissected away from the surrounding tissues and totally removed. The postoperative course was uneventful, and the preoperative neurological deficits gradually resolved. Histopathologically, the lesion was a schwannoma with intratumoral hemorrhage. Conclusion: This case demonstrates the rare acute presentation of a T12-L1 schwannoma with an accompanying intratumoral hemorrhage resulting in both a SDH/SAH.

Background: Blake’s pouch cyst (BPC) is a posterior fossa cystic malformation that commonly occurs in children with rare adult onset. Herein, we report a case of adult onsets BPC. Case Description: A 61-year-old man presented with gait and cognitive disturbance. Preoperative magnetic resonance imaging (MRI) revealed scarring in the prepontine cistern, and cine phase-contrast MRI revealed no pulsation. Endoscopic third ventriculostomy (ETV) was performed with opening the scarring in the prepontine cistern. Postoperative cine phase-contrast MRI revealed that cerebrospinal fluid (CSF) flow in the prepontine cistern improved, resolving the patient’s symptoms. Conclusion: We report a case of adult-onset BPC. The mechanism by which is becomes symptomatic is still unclear. We opened the scar in prepontine cistern in addition to ETV with good results. In this report, we discussed the importance of the improvement in CSF dynamics in the prepontine cistern.