Dermatofibrosarcoma protuberans: report of a case with a variant ring chromosome and metastases following pregnancy.
BACKGROUND
The most frequent molecular abnormality observed in dermatofibrosarcoma protuberans (DFSP) is the formation of a supernumerary ring chromosome or translocation resulting in fusion of the gene encoding the alpha-chain of type 1 collagen, COL1A1 from 17q22, to the platelet-derived growth factor beta-chain, PDGFB gene from 22q13. Rare cases documenting variant ring or marker chromosomes involving regions other than 17q22 and 22q13 have been reported. Further analysis in three of these cases demonstrated the presence of the COL1A1 and PDGFB genes.


METHODS
We report a further case of DFSP with a rare variant ring chromosome. The tumor appeared to undergo accelerated growth during pregnancy, then metastasized following pregnancy. We describe the clinical, histological, immunohistochemical, and cytogenetic features.


RESULTS
The metastatic tumor showed a variant r(17;?) chromosome. A locus-specific probe was required to demonstrate presence of the PDGFB gene within the ring, indicating cryptic molecular rearrangement between chromosomes 17 and 22, and recombination with an unknown chromosome.


CONCLUSIONS
Cryptic rearrangement of chromosomes 17 and 22 should be suspected in variant ring chromosomes and translocations. Pregnancy may contribute to accelerated growth of DFSP, and delay in surgical resection should be avoided.
Bigby
Susan M
SM
Department of Histopathology, Diagnostic-Medlab, Auckland, New Zealand.
Oei
Paul
P
Lambie
Neil K
NK
Symmans
Pennie J
PJ
D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001549:Benzamides; D001943:Breast Neoplasms / Q000188:drug therapy / Q000556:secondary / Q000601:surgery; D018223:Dermatofibrosarcoma / Q000235:genetics* / Q000473:pathology* / Q000556:secondary; D005260:Female; D006801:Humans; D000068877:Imatinib Mesylate; D017403:In Situ Hybridization; D008175:Lung Neoplasms / Q000188:drug therapy / Q000556:secondary; D008408:Mastectomy; D010879:Piperazines / Q000627:therapeutic use; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000235:genetics* / Q000473:pathology; D011743:Pyrimidines / Q000627:therapeutic use; D012303:Ring Chromosomes; D012878:Skin Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000601:surgery
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate