Although most nevi are benign, malignant transformation may cause melanocytic nevi.
The molecular pathways that distinguish malignant from benign parathyroid transformation remain elusive.
Although it is a benign lesion, malignant transformation has been reported [2].
LPD is rare (<200 cases reported), essentially benign, though malignant transformation has been reported [4].
The decrease or deletion of the expression of E-cadherin leads to the loss of contact inhibition and unrestricted hyperplasia, the loss of intercellular junction with, stronger invasive ability, enhanced tumor cell diffusion and metastasis, as well as benign tumor malignant transformation in some extreme cases [21], [22], [23].
Despite the identification of these key parathyroid tumor suppressor genes, the mechanisms and pathways that distinguish benign from malignant transformation of the parathyroid remain elusive.
Preliminary data using cell lines indicates that KiSS1 expression is lost as melanoma cells convert from radial to vertical growth phase (benign to malignant transformation) [ 22], but more extensive clinical studies have been slowed due to lack of suitable antibodies.
If a similar process takes place in humans and these remnants remain dormant for years, then the transitional atypical tissue seen in our study is likely benign to malignant transformation in progress.
Studies on a larger number of prostate samples, including both neoplastic and non-cancerous prostate, would further clarify this issue and should generate a link between the pathological cascade including infection, inflammatory response and amyloid deposition with benign and malignant transformations in the prostate gland.
Thus, in the chapter on bone tumours, the authors consider pre-existing conditions and aetiologic factors together and the account of soft tissue tumours concerns benign to malignant transformations, progression from low-grade to high-grade malignancies, and specific chromosomal translocations.
