Transformation Of Schwannoma Research Articles

A mechanistic mathematical model of initiation and malignant transformation in sporadic vestibular schwannoma

BackgroundA vestibular schwannoma (VS) is a relatively rare, benign tumour of the eighth cranial nerve, often involving alterations to the gene NF2. Previous mathematical models of schwannoma incidence have not attempted to account for alterations in specific genes, and could not distinguish between nonsense mutations and loss of heterozygosity (LOH).MethodsHere, we present a mechanistic approach to modelling initiation and malignant transformation in schwannoma. Each parameter is associated with a specific gene or mechanism operative in Schwann cells, and can be determined by combining incidence data with empirical frequencies of pathogenic variants and LOH.ResultsThis results in new estimates for the base-pair mutation rate u = 4.48 × 10−10 and the rate of LOH = 2.03 × 10−6/yr in Schwann cells. In addition to new parameter estimates, we extend the approach to estimate the risk of both spontaneous and radiation-induced malignant transformation.DiscussionWe conclude that radiotherapy is likely to have a negligible excess risk of malignancy for sporadic VS, with a possible exception of rapidly growing tumours.

Lobular Breast Carcinoma Metastasis to a Superficial Plexiform Schwannoma as the First Evidence of an Occult Breast Cancer

Tumor to tumor metastasis is a rare phenomenon, in which one, benign or malignant, tumor is involved by metastatic deposits from another. Most documented tumor to tumor metastases have been located intracranially, in which, in the majority of cases, either a breast or a lung carcinoma metastasized to a meningioma. Only 7 cases of metastases to schwannoma have so far been reported in the English literature, in 6 cases to an intracranial acoustic schwannoma and in a single case to a subcutaneous schwannoma. We present a case of dermal/subcutaneous plexiform schwannoma containing metastatic deposits of an occult lobular breast carcinoma, creating a unique schwannoma with epithelioid cells. Differential diagnosis of schwannoma with epithelioid cells includes malignant transformation of schwannoma and metastasis of a carcinoma or melanoma to schwannoma, epithelioid schwannoma, and schwannoma with glandular or pseudo glandular elements.