NUCHAL-TYPE FIBROMA: A CASE REPORT Scibetta Nunzia, Marasà Lorenzo C.O.U. of Pathologic Anatomy, ARNAS-Civico Hospital, Palermo, Italy.

Nuchal-type fibroma (NTF) is a rare, tumorlike proliferation typically located in the subcutaneous tissues of the posterior neck and interscapular regions of patients between ages 25 and 60 years. The lesion has a low recurrence following excision, not metastatize and has a strong association with diabetes and Gardner’s syndrome.

Materials and methods A 72-year old man presented with a mass in the posterior neck region. It was locally excised. Gardner’s syndrome and diabetes mellitus has not been documented. Specimens had been fixed in 4% formaldehyde and embedded in paraplast. Sections 4 micron thick were stained with H&E and Van Gieson stain. Immunohistochemistry was performed.

Results The poorly circumscribed, whitish, subcutaneous, 2 cm in the greatest diameter excised mass, microscopically was paucicellular and composed of thick, irregularly arranged bundles of collagen, and scattered fibroblast, with island of trapped adipose tissues, and a localized proliferation of nerve twigs, similar to that seen in traumatic neuroma. A delicate network of elastic fibres is observed between the collagen fibres. The fibroblast-like cells were positive for vimentin and CD34, negative for actin, desmin, S100, GFAP.

H&E x 100 Van Gieson staining x 200 NTF contain thick, haphazardly arranged collagen fibers

H&E x 100 S100 protein x100 Irregularly arranged bundles of collagen with scattered island of trapped adipose tissue and small nerves with haphazardly arranged fascicles

S100 protein x200 S100 protein x400 Entrapped peripheral nerve exhibiting a splayed appearance similar to that of traumatic neuroma

Entrapped peripheral nerve exhibiting a splayed appearance similar to that of traumatic neuroma (S100 protein, x 400)

NTFs, typically present in the posterior neck region, appear to represent a localized accentuation of the collagenous connective tissue that normally resides in these sites. NTF represents a peculiar, non neoplastic tumorlike reactive process and should be distinguished from other fibrous tumors and tumor like conditions, especially the desmoids-type fibromatosis, circumscribed storiform collagenoma, collagenous fibroma, lipoma. Local recurrence probably reflects the persistence of local or systemic factor related to its pathogenesis. Conclusions

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