Acral Cutaneous Intraneural Pseudoperineurioma

Area of Science:

• Dermatopathology
• Histopathology
• Oncology

Background:

• Cutaneous neurovascular stromal lesions are poorly defined, leading to misdiagnosis.
• Existing literature lacks comprehensive data on their prevalence and classification.

Purpose of the Study:

• To elucidate the histopathologic, histochemical, and immunohistochemical characteristics of acral nodular tumors with perineuriomatous differentiation.
• To establish a potential distinct clinicopathologic entity for these lesions.

Main Methods:

• Analysis of 3 cases of hand nodules in teenagers from a larger cohort of 1331 patients.
• Histopathologic examination using Masson trichrome, Alcian blue staining.
• Immunohistochemical analysis with CD31, ERG, smooth muscle actin, CD34, S100, SOX10, neurofilament, EMA, and GLUT1.

Main Results:

• Nodules showed dermal-based growths with tortuous neurovascular bundles and collagenous stroma.
• Distinct perineurial differentiation (EMA, GLUT1 positive) within neurovascular bundles and onion-bulb structures.
• Sparse neural components (S100, SOX10, neurofilament positive) were observed.

Conclusions:

• The findings suggest cutaneous intraneural pseudoperineurioma nodules may be a distinct entity.
• These lesions resemble cutaneous intraneural perineurioma but may differ.
• Further validation and molecular studies are needed due to the small sample size.