Lipofibromatosis-like neural tumor

Lipofibromatosis-like neural tumor (LPF-NT) is an extremely rare soft tissue tumor first described by Agaram et al in 2016. As of mid-2021, at least 39 cases of LPF-NT have been reported in the literature. LPF-NT tumors have several features that resemble lipofibromatosis (LPF) tumors, malignant peripheral nerve sheath tumors, spindle cell sarcomas, low-grade neural tumors, peripheral nerve sheath tumors, and other less clearly defined tumors; Prior to the Agaram at al report, LPF-NTs were likely diagnosed as variants or atypical forms of these tumors. The analyses of Agaram at al and subsequent studies uncovered critical differences between LPF-NT and the other tumor forms which suggest that it is a distinct tumor entity differing not only from lipofibromatosis but also the other tumor forms.

LPF-NTs are locally invasive, are commonly treated by surgical excision, and have a relatively high rate of local recurrence if their surgical excisions are incomplete. They are generally considered to be benign, non-metastasizing (i.e. not spreading to other parts of the body) tumors. However, one case of LFT-NT reported by Agaram et al was associated with metastasis, apparently as a result of the tumor's cells transformation into a malignant sarcoma. Further studies are needed to determine the frequency of such cases and the overall metastatic potential of LPF-NT.

LPF-NTs were given the "neural tumor" terminology because in at least some cases: 1) their tumor cells express S100 and CD34 but not SOX10 proteins, a pattern that is often found in neural and neuroectodermal tumor cells; and 2) their histopathology consists of tumor cell infiltrations into adipose tissues in a pattern that is very similar to that found in some low grade malignant peripheral nerve sheath tumors.