Giant nodular fasciitis originating from the humeral periosteum: A case report

Table 2 Primary differential diagnosis

Tumor type	Epidemiology	Clinical features	Size	Histopathology	Immunophenotype	Genetics
Nodular fasciitis	Young adults, no gender difference	Grows rapidly, painless, recurrence is rare	Median size, ≤ 2 cm (always < 5 cm)	Spindle-shaped fibroblasts, growth in S- or C- shaped, interstitium is loose and myxoid, visible exosmosis of erythrocytes	Positive: SMA, Calponin, CD10; negative: S100, CD34, nuclear β-catenin	MYH9–USP6 gene fusion
Low-grade fibromyxoid sarcoma	Typically affect young adults, no gender difference	Slow growth, no pain, easy recurrence	Median size, 5 cm (1-20 cm)	Original glue and myxoid region are mixed, spindle cell, small blood vessels, early formation of collagen rosettes	EMA positive from focally to 80%, MUC4 positive has high sensitivity and specificity	FUS-CREB3L2 or FUS-CREB3L1 gene fusion
Low-grade myofibroblastic sarcoma	Predominantly in adults, 40-50 yr see more, slight predominance in males	Enlarging mass, painless, easy recurrence	Median size, 4 cm (1.4-17 cm)	Diffusely infiltrative growth, spindle cells arranged in a storiform pattern or fascicles	Positive: actin, desmin, calponin, CD34 (focal); negative: S100, nuclear β-catenin	Only one showed a circular chromosome
Low-grade myxofibrosarcoma	Elderly patients, over 60 yr, slight predominance in males	Slowly enlarging, painless, easy recurrence	Larger volume (range variable)	Spindle cells, mild atypia, curvilinear thin-walled blood vessels, pseudolipoblasts	Positive: SMA, negative: Desmin and histiocyte-specific markers	No specific aberration