Concurrent PTEN and PDGFRB Alterations Characterize Storiform Collagenoma

Area of Science:

• Dermatology
• Oncology
• Molecular Biology

Background:

• Storiform collagenoma is a rare mesenchymal skin tumor characterized by specific collagen patterns and CD34-positive spindle cells.
• While often sporadic, it can be associated with Cowden syndrome, linked to PTEN gene alterations.
• The molecular underpinnings of storiform collagenoma require further investigation.

Purpose of the Study:

• To investigate the molecular pathogenesis of storiform collagenoma.
• To identify genetic alterations in both sporadic and Cowden syndrome-associated cases.
• To explore the roles of PTEN and PDGFRB in tumor development.

Main Methods:

• Targeted next-generation DNA sequencing was employed.
• Analysis included five sporadic cases and one case associated with Cowden syndrome.
• PTEN and PDGFRB genes were specifically examined.

Main Results:

• Recurrent PTEN alterations were found in all investigated cases.
• Biallelic PTEN inactivation was observed in one Cowden syndrome-associated and one sporadic case.
• Activating mutations in PDGFRB were identified in all cases, including a D5 Ig-like domain mutation in the Cowden syndrome case and juxtamembrane domain mutations in 80% of sporadic cases.

Conclusions:

• The study confirms the neoplastic nature of storiform collagenoma.
• It expands the known spectrum of PDGFRB alterations in mesenchymal tumors.
• PTEN and PDGFRB alterations likely play collaborative roles in the pathogenesis of storiform collagenoma.