TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: FC13A    
Factor 13a (FAC13A) Immunostain, Technical Component Only

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

Aids in the identification of acquired digital fibrokeratomas, angiofibromas, and oral fibroma, and a proportion of cells in histiocytomas

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

For the initial technical component only immunohistochemical (IHC) stain performed, the appropriate bill-only test ID will be reflexed and charged (IHTOI). For each additional technical component only IHC stain performed, an additional bill-only test ID will be reflexed and charged (IHTOA).

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

Factor XIIIa, a blood and intracellularly produced coagulation factor, has been found in a variety of cell types, including fibroblast-like mesenchymal cells, and has been shown to stimulate the proliferation of fibroblasts and neoplastic cells in vitro. Immunohistochemical staining for factor XIIIa labels normal dermal dendrocytes, the large stellate fibroblasts found in acquired digital fibrokeratomas, angiofibromas, and oral fibroma, and a proportion of cells in histiocytomas. Factor XIIIa immunostain also produces cytoplasmic staining of dermal dendrocytes in normal skin and of a proportion of cells in histiocytomas.

Interpretation Provides information to assist in interpretation of the test results

This test includes only technical performance of the stain (no pathologist interpretation is performed). Mayo Clinic cannot provide an interpretation of tech only stains outside the context of a pathology consultation. If an interpretation is needed, refer to PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case. All material associated with the case is required. Additional specific stains may be requested as part of the pathology consultation, and will be performed as necessary at the discretion of the Mayo pathologist.

 

The positive and negative controls are verified as showing appropriate immunoreactivity and documentation is retained at Mayo Clinic Rochester. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request. Contact 855-516-8404.

 

Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

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

Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen-dependent. Best practice is for paraffin sections to be cut fresh.

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

1. Goldblum JR, Tuthill RJ: CD34 and Factor-XIIIa immunoreactivity in dermatofibrosarcoma protuberans and dermatofibroma. The American Journal of Dermatopathology 1997;19(2):147-153

2. Gray MH, Smoller BR, McNutt S, Hsu A: Immunohistochemical demonstration of Factor XIIIa expression in neurofibromas. A practical means of differentiating these tumors from neurotized melanocyte nevi and schwannomas. Arch Dermatol 1990;126(4):472-476

3. Zoltan N, Vilmos T: Factor XIIIa and the classic histiocytic markers in malignant fibrous histiocytoma: A comparative immunotochemical study. Human Pathology 1988;19(7):822-829