[40] Karyotyping Myofibroblastic/Fibroblastic Tumors: Continuing Usefulness of Standard Cytogenetic Methods in Detecting Novel Genetic Findings and Confirming the Histologic Diagnosis

Megan Fitzpatrick, Francine Leech, David Meredith, Robert Quinn, Therese Bocklage. University of New Mexico School of Medicine, Albuquerque, NM; UNM SOM, Albuquerque, NM

Background: Myofibroblastic/Fibroblastic tumors encompass a broad variety of benign to borderline to malignant tumors. The category continues to undergo change as tumors are more accurately classified. Because this is a large, diverse category, karyotypic information is limited. Classic cytogenetics is still helpful in providing first leads to uncover molecular level abnormalities. However, artifacts of long term in-situ culture must be recognized and threshed from the harvest of findings.
Design: Karyotypes of myofibroblastic/fibroblastic tumors (M-FT) according to W.H.O. 2002 classification and recently proposed M-FT were searched for in the cytogenetics database at our institution for 2001-2011 (to October 1). Twelve categories of tumors were identified. Tumors were stratified according to: 1) successful culture, 2) normal karyotype (possible fibroblast overgrowth), 3) abnormal clonal karyotype expected for the histologic diagnosis, and 4) novel abnormal karyotype. Percent successful karyotype per tumor type and percent non-clonal cell lines were calculated. Length in time in culture and type of specimen (biopsy, resection, re-exision) were noted in conjunction with tumor diagnosis, location, size, grade, and stage.
Results: The results are provided in table form.

MYOFIBRO-FIBROBLASTIC TUMOR KARYOTYPES
TUMORNUMBERNUMBER SUCCESSFULLY KARYOTYPEDNUMBER WITH NORMAL KARYOTYPENUMBER WITH EXPECTED KARYOTYPENUMBER WITH NOVEL ABNORMAL KARYOTYPEPERCENT WITH ABNORMAL KARYOTYPE
NODULAR FASCIITIS8640233%
DESMOID TUMOR2319163016%
CALCIFYING APONEUROTIC FIBROMA21001100%
DFSP5530260%
FIBROSARCOMA ARISING IN DFSP22002100%
INFLAMMATORY MYOFIBROBLASTIC TUMOR2211050%
LOW GRADE FIBROMYXOID SARCOMA9722371%
SCLEROSING EPITHELIOID FIBROSARCOMA11010100%
MYOFIBROSARCOMA32002100%
MYXOFIBROSARCOMA2321813062%
DESMOPLASTIC FIBROBLASTOMA11001100%
MYOFIBROBLASTIC/FIBROBLASTIC TUMOR NOS9630350%


Fifty percent of cases exhibited secondary non-clonal abnormalities; 28% of these "non-clonal" changes were closely related to the clonal change, reproduced in subsequent specimens as "non-clonal" or showed abnormalities consistent with the clinical history and morphology.
Conclusions: While expensive and labor intensive, in selected circumstances, judiciously examined, traditional karyotypes can provide new information helpful in evaluating the pathogenesis of and relationships among myofibroblasti/fibroblastic tumors.
Category: Bone & Soft Tissue

Monday, March 19, 2012 1:00 PM

Poster Session II # 26, Monday Afternoon

 

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