Neural neoplasms Flashcards
Traumatic neuroma
- Reactive proliferation of nerve fibres at sites if trauma -> arises from attempted regeneration of nerve
- Flesh-coloured firm papule or nodules
- Painful
- Histology: variably sized/shaped, haphazardly distributed small nerve bundles (resemble normal nerves, in that Schwann cells and axonal components are present in a 1:1 ratio
- Background scar
- S100+ and neurofilents (stains axons)
Palisaded enscapsulated neuroma (solitary circumscribed neuroma)
Schwannoma (neurilemmoma)
Neurofibroma
Nerve sheath myxoma (“neurothekeom”)
Cellular neurothekeoma
- Benign neoplasm: uncertain histiogenesis
- Firm, pink papules on face of young adults (20-30y old), F>M
- Histology: dermal prolif, nests and fasicles of epithelioid cells (cells resemble spitz nevus cells or sarcoidal histiocytes)
- Boards favourite: always S100 negative (vs classic ‘neurothekeoma’), but S100A6+, NKI/C3+ and PGP 9.5+
Granular cell tumor
Malignant peripheral nerve sheath tumor
- Presents as a rapidly growing nodule within a plexiform neurofibroma (lifetime risk: 2-13%), may have large overlying CALM
- Histology: densely cellular proliferation of atypical spindle cells often with large areas of necrosis (“geographic necrosis”) and high mitotic rate
Merkel cell carcinoma
Neuroblastoma
Heterotopic meningeal tissue
Perineuriomas - key features of extraneural variants of interest to dermatologist
Histologic differential diagnostic features of common cutaneous neural neoplasms
Classification of cutaneous neural and neuroendocrine tumors
Clinical features of benign neural neoplasms
Primary cutaneous merkel cell carcinoma (MCC): simplified evaluation and treatent
Merkel cell carcinoma - 8th AJCC Staging system
Immunohistochemical staining of cutaneous neural neoplasms and the major tumors in the differential diagnosis
picture of solitary schwannkma
Picture of cellular neurothekeoma
