Dermal lipofibromatosis-like neural tumor.

BACKGROUND

Lipofibromatosis-like neural tumor (LPF-NT) is a rare soft tissue typically occurring in the subcutis, characterized by a cellular proliferation of CD34- and S100-protein positive spindle-shaped tumor cells with an infiltrative growth pattern.

OBJECTIVE

To describe five cases arising mainly in the dermis in order to expand their morphologic spectrum.

METHODS

H&E slides were reviewed, and all cases were stained for CD34, SOX10, S100, ALK, and NTRK1 and some of them with additional staining.

RESULTS

Patients were three males and two females with a mean age of 44.8 years (14-68 years). Histopathologically, all cases were characterized by a dense dermal infiltration by monomorphous, mildly atypical, plump to spindle-shaped tumor cells, staining diffusely positive for CD34, S100, and NTRK1 but were negative for S100, EMA, NKIC3, MNF116, SMA, ALK, and desmin.

LIMITATIONS

Limited clinical information.

CONCLUSION

LPL-NT can be located mainly in the dermis. Sixty percent of our cases showed typical areas of LPL-NT intermingled with more plump cells like the ones in fibrous hamartoma of infancy. We recommend a panel of CD34, S100, and NTRK1 antibodies not only in subcutaneous spindle cell neoplasms but also in the ones predominantly involving the dermis in order to make an accurate diagnosis.