Test Catalog

Test ID: USPF    
USP6 (17p13), Aneurysmal Bone Cyst and Nodular Fasciitis, FISH, Tissue

Useful For Suggests clinical disorders or settings where the test may be helpful

Supporting the diagnosis of aneurysmal bone cyst or nodular fasciitis

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

This test does not include a pathology consultation. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered and the appropriate FISH test will be ordered and performed at an additional charge.


This test includes a charge for application of the first probe set (2 FISH probes) and professional interpretation of results.


Additional charges will be incurred for all reflex probes performed. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cells are available for analysis, no analysis charges will be incurred.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Aneurysmal bone cyst (ABC) is a multicystic and expansile bone tumor of uncertain line of differentiation. USP6 rearrangements are detectable in approximately 70% of primary ABC and not in other conditions that may simulate ABC histologically, including giant cell tumor of bone, osteosarcoma, osteoblastoma, brown tumor, cherubism, and vascular neoplasms.


Nodular fasciitis (NF) is a self-limited mesenchymal lesion of myofibroblastic differentiation. NF’s rapid growth, rich cellularity, and brisk mitotic activity may lead to a misdiagnosis of sarcoma.


USP6 rearrangements are detectable in 90% of NF but not in other conditions that may simulate NF, including dermatofibroma, cellular fibrous histiocytoma, fibromatosis, and a large variety of sarcomas.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Interpretation Provides information to assist in interpretation of the test results

A neoplastic clone is detected when the percent of cells with an abnormality exceeds the normal reference range for the USP6 FISH probe (positive result).


A positive result is consistent with rearrangement of the USP6 gene locus on 17p13 and supports the diagnosis of aneurysmal bone cyst (ABC) or nodular fasciitis (NF).


A negative result is consistent with no rearrangement of the USP6 gene locus on 17p13.


However, this result does not exclude the diagnosis of ABC or NF. Rearrangement varies in individual tumors and among different cells in the same tumor.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test is not approved by the FDA and it is best used as an adjunct to existing clinical and pathologic information.


Fixatives other than formalin (eg Prefer, Bouin) may not be successful for FISH assays, however nonformalin-fixed samples will not be rejected.


Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing.

Supportive Data

FISH analysis was performed on 101 samples including 14 primary aneurysmal bone cyst (ABC), 48 nodular fasciitis (NF), and 39 control formalin-fixed paraffin-embedded tissue samples. The normal controls were used to generate a normal cutoff for this assay. A rearrangement of USP6 was identified in 11 of 14 (77%) and 44 of 48 (92%) NF samples.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Oliveira AM, Hsi B, Weremowicz S, et al: USP6 (Tre2) fusion oncogenes in aneurysmal bone cyst. Cancer Res 2004 Mar 15;64(6):1920-1923

2. Oliveira AM, Perez-Atayde AR, Inwards CY, et al: USP6 and CDH11 oncogenes identify the neoplastic cell in primary aneurysmal bone cysts and are absent in so-called secondary aneurysmal bone cysts. Am J Pathol 2004 Nov;165(5):1773-1780

3. Fletcher CDM, Unni KK, Mertens F: World Health Organization Classification of Tumours. Pathology and Genetics of Tumours of Soft Tissue and Bone. IARC Press, Lyon, France, 2005, pp 48-49

4. Erickson-Johnson MR, Chou MM, Evers BR, et al: Fusion of Non-Muscle Myosin MYH9 to USP6 Oncogene in Nodular Fasciitis, USCAP Abstract #39, 2011