Adjacent epidermoid cyst and primary central nervous system lymphoma: case report

Intracranial Dermoid in Patients With Fibrous Dysplasia

OBJECTIVES

Intracranial epidermoid cyst (EC) and craniofacial fibrous dysplasia (CFD) were histogenetically different rare congenital benign diseases. The coexistence of intracranial EC and CFD was extremely rare and had not been reported yet.

MATERIALS AND METHODS

We retrospectively reviewed the clinical and radiologic information of 3 patients diagnosed with concomitant EC and CFD at Beijing Tiantan Hospital from January 2003 to January 2021 and summarized their clinicopathological features, treatment modalities, and outcomes. In addition, we performed a systematic review of cases of the coexisting intracranial EC and other intracranial abnormalities to explore the potential connections.

RESULTS

There were 2 women and 1 man with the mean age of 31 years old. Satisfactory resection was fulfilled for all the 3 ECs. CFD, however, was managed with watchful waiting. During the mean follow-up time of 58 months, all the ECs showed no sign of recurrence, and all the CFD lesions remained stable. Two EC specimens underwent genetic study, showing no GNAS mutations and negative Gsα protein expression. In the literature review of concomitant intracranial EC and other intracranial abnormalities, 23 studies were included. With 5 reported cases, the intracranial aneurysm was found to be the most common intracranial disease that coexisted with EC.

CONCLUSIONS

The coexistence of intracranial EC and CFD was extremely rare. However, no convincing mechanism and evidence underlying such coexistence had been found. To provide more profound understanding about these 2 diseases and improve diagnosis and treatment strategy, further research and verification should be considered.

Brain lymphoma development related to a long lasting epidermoid cyst

INTRODUCTION

Epidermoid cysts (EC) are benign and slow growing lesions. A primary brain lymphoma development related to a EC is presented, second case described in literature.

CASE PRESENTATION

A woman 40 years old, harbouring a EC for more than 20 years, develops a fast growing brain lesion next to the EC. Surgery was performed and diagnosis was primary diffuse B cells lymphoma.

DISCUSSION

Malignant transformation of EC has been described, usually to squamous cells carcinoma, and much less frequently, to another tumours. Inflammatory mechanisms have been advocated to explain this evolution. Chronic inflammation and lymphoma genesis are related, and this could be the mechanism behind this rare evolution of an EC.

CONCLUSIONS

Even being benign lesions, EC can develop malignant tumours due to the chronic inflammation secondary to them.

Brain lymphoma development related to a long lasting epidermoid cyst

INTRODUCTION

Epidermoid cysts (EC) are benign and slow growing lesions. A primary brain lymphoma development related to a EC is presented, second case described in literature.

CASE PRESENTATION

A woman 40 years old, harbouring a EC for more than 20 years, develops a fast growing brain lesion next to the EC. Surgery was performed and diagnosis was primary diffuse B cells lymphoma.

DISCUSSION

Malignant transformation of EC has been described, usually to squamous cells carcinoma, and much less frequently, to another tumours. Inflammatory mechanisms have been advocated to explain this evolution. Chronic inflammation and lymphoma genesis are related, and this could be the mechanism behind this rare evolution of an EC.

CONCLUSIONS

Even being benign lesions, EC can develop malignant tumours due to the chronic inflammation secondary to them.

Primary central nervous system lymphomas associated with chronic inflammation: diagnostic pitfalls of central nervous system lymphomas

In recent years, the features of lymphomas associated with chronic inflammation, referred to as diffuse large B-cell lymphoma (DLBCL) associated with chronic inflammation (DLBCL-CI), have been elucidated. DLBCL-CI is an aggressive lymphoma occurring in the context of long-standing chronic inflammation and showing an association with Epstein-Barr virus. Fibrin-associated diffuse large B-cell lymphoma (F-DLBCL) was suggested as a new and unusual form of DLBCL-CI in the most recent version of the World Health Organization classification. From the perspective of genetics, DLBCL-CI was associated with frequent TP53 mutation, MYC amplification and complex karyotypes, but cases of F-DLBCL behaved indolently and showed a relatively lower genetic complexity. In the central nervous system (CNS), several examples of DLBCL-CI and F-DLBCL have been reported. As with DLBCL-CI outside the CNS, DLBCL-CI in the CNS is an aggressive lymphoma. However, the clinical outcome of F-DLBCL in the CNS is good. Immunohistochemistry for p53 and c-Myc in DLBCL-CI and F-DLBCL in the CNS showed similar findings of those outside the CNS. However, one aggressive case showed transitional genetics and morphology between F-DLBCL and DLBCL-CI. These findings suggest that some cases of F-DLBCL in the CNS might have the potential to progress to DLBCL-CI.

Malignant transformation of an epidermoid cyst in the temporal and prepontine region: Report of a case and differential diagnosis

Malignant transformation of an epidermoid cyst is rare. The current report presents a case of a 55-year-old female patient with squamous cell carcinoma arising from a benign epidermoid cyst in the left temporal region and prepontine area. She had undergone subtotal resection of an epidermoid cyst 7 months previously. Preoperative imaging findings included a focal enhancing area adjacent to the lesion. Postoperative computed tomography demonstrated an increase in the size of the enhancing area. The patient underwent removal of the lesion and postoperative histological examination revealed a squamous cell carcinoma possibly arising from the epidermoid cyst. Accurate diagnosis of malignant transformation prior to operation is difficult; however, the possibility of an intracranial epidermoid cyst must be considered if a focally enhancing area is visible. Postoperative histological examinations may be used to determine a definite diagnosis, and accurate diagnosis is important for planning a rational therapeutic strategy.

MR imaging features of intracranial primary CNS lymphoma in immune competent patients

We aimed to characterize specific MRI findings seen in immune competent patients with intracranial primary CNS lymphoma (PCNSL) and to determine their value in the management of such patients. Pre-treatment MRI examinations of 21 immunocompetent patients with biopsy-proven PCNSL were retrospectively evaluated. T1 and T2 signal characteristics as well as contrast enhancement features are described in all patients. Diffusion, perfusion and proton-MR-spectroscopy features are described in a subset of these patients. In the proper clinical and radiologic setting, suggesting the diagnosis of PCNSL can help institute proper treatment in a timely fashion and avoid unnecessary attempts at surgical resection and the associated morbidity.

Cyst with a mural nodule tumor of the brain

The purpose of this article is to illustrate the imaging findings of lesions that present as cyst with a mural nodule tumor (CMNT). CMNT is a subtype pattern of intra-axial enhancement in central nervous system tumors, typical of a variety of brain neoplasms, including, as the most common, hemangioblastoma, pilocytic astrocytoma, ganglioglioma and pleomorphic xanthoastrocytoma and as less common tanycytic ependymoma, intraparenchymal schwannoma, desmoplastic infantile ganglioglioma and cystic metastasis. A retrospective design was chosen given the rarity of CMNT. Relevant cases were obtained retrospectively to review the different lesions that can present with the appearance of CMNT.