| PSEUDOSARCOMAS
[Robins pp 1263
- 1264] Types
of lesions
- Nodular fasciitis
also known as infiltrative or pseudosarcomatous
fasciitis
- Proliferative
fasciitis
- Proliferative
myositis
Gross Appearance
Pseudosarcomas are
nodular, gray tumors with poorly defined margins.
Histologic Features
(Robbins Fig 27-53;
p 1263)
These tumors consist
of a cellular proliferation of randomly arranged,
plump, immature fibroblasts. Intercellular collagen
is sparse. There is focal, excessive production of
extracellular matrix. Extravasated red cells may also
be present.
Clinical Correlation
Pseudosarcomas are
rapidly growing lesions that are sometimes painful.
Nodular fasciitis
occurs in young adults. These superficial lesions are
located on the volar aspect of the arm, the chest and
back.
Proliferative
fasciitis and myositis occur in older patients and
the lesions are located in the proximal extremities.
*Note*
Pseudosarcomas are benign,
non-neoplastic, reactive lesions.
Morphologic features that mimic a true sarcoma
are mitotic activity, cellularity and immature
appearance of the proliferating cells.
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