Dermal lipofibromatosis‐like neural tumor

Abstract

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.

Lipofibromatosis‐like neural tumors: Report of a case and review of 73 reported cases

“…Spindle cells typically have no to mild cytomorphologic atypia and low mitotic activity. Most reported cases with mitotic counts had less than 4 mitotic figures per 10 high‐power fields 1,4,9–11 . In addition to these characteristic findings, lymphocytic infiltrates, pigmented dendritic melanocytes, staghorn vessels, and perivascular hyalinization may be present 9,13,17 …”

“…Since the 2016 publication, the spectrum of morphologic and molecular characteristics observed in these tumors has expanded. To date, at least 73 cases described as LPF-NT have been reported in the literature, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] based on the presence of lipofibromatosis-like morphology and suggestive molecular features. The characteristics of these 73 cases and our case are described in Table 1.…”

“…Most reported cases with mitotic counts had less than 4 mitotic figures per 10 high-power fields. 1,4,[9][10][11] In addition to these characteristic findings, lymphocytic infiltrates, pigmented dendritic melanocytes, staghorn vessels, and perivascular hyalinization may be present. 9,13,17 Due to the diverse histopathological spectrum seen in LPF-NTs, molecular testing is critical for accurate diagnosis and treatment.…”

Dermatofibrosarcoma protuberans of the face: A clinicopathologic and molecular study of 34 cases

“…Although dermatomyofibromas may show limited CD34 expression, they lack the storiform growth pattern and infiltrative growth pattern observed in DFSP. Although dermal lipofibromatosis-like neural tumor (LPF-NT) is a CD34-protein positive spindle-shaped tumor with an infiltrative growth pattern, S100-and NTRK1-negative spindled cells with storiform pattern and a honeycomb pattern of subcutaneous fat infiltration negated a diagnosis of LPF-NT [23]. Plaque-like CD34-positive dermal fibroma resembles plaque-like DFSP in histology, but negative PDG-FB amplification can potentially assist in the differential diagnosis [24].…”

Dermatofibrosarcoma protuberans im Gesicht: Klinisch‐pathologische und molekulare Studie mit 34 Fällen

“…Dermatomyofibrome wiederum können eine gewisse CD34‐Proteinexpression aufweisen, jedoch fehlt das storiforme Wachstumsmuster und die infiltrative Ausbreitung wie es beim DFSP beobachtet wird. Dermale LPF‐NT (lipofibromatosis‐like neural tumors) sind CD34‐Protein‐positive Tumore mit Spindelzellen und infiltrativem Wachstum, jedoch schließen S100‐ und NTRK1‐negative Spindelzellen mit storiformem Muster und einer wabenartigen Infiltration des subkutanen Fettgewebes die Diagnose LPF‐NT aus [23]. Plaque‐artige CD34‐positive dermale Fibrome sehen histologisch ähnlich aus wie plaque‐artige DFSP, aber hier kann die negative PDGFB ‐Amplifizierung möglicherweise bei der Diagnose helfen [24].…”