Fine-needle aspiration of dermatofibrosarcoma protuberans metastasizing to hemithorax with superior vena cava compression: Case report and literature review.
Diagn Cytopathol 2019;
47:797-802. [PMID:
30919592 DOI:
10.1002/dc.24179]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 03/03/2019] [Accepted: 03/07/2019] [Indexed: 11/07/2022]
Abstract
Dermatofibrosarcoma protuberans (DFSP) is a low-grade spindle cell tumor of the skin commonly arising on the trunk and extremities which tends to be slow growing yet locally aggressive. DFSPs are associated with a good prognosis when surgical excision with negative margins is achieved. Although local recurrences occur up to 50% of incompletely resected cases, distant metastases are very rare. Here, we report a case of DFSP metastasizing to the right hemithorax diagnosed by an endobronchial ultrasound-guided fine-needle aspiration (FNA) 9 years after initial presentation. The aspirate showed a bland spindle cell proliferation that was morphologically similar to the original skin excision; the storiform pattern was particularly prominent in tumor-tissue fragments in the cellblock. Immunostaining showed strong, diffuse positivity for CD34. Molecular studies demonstrated a characteristic COL1A1/PDGFB fusion in both original and metastatic specimens. A review of the literature revealed that metastatic DFSP most often involves the lungs, occurs usually in cases with fibrosarcomatous transformation and after a local recurrence, and presents on average 4.5 years after the original diagnosis. This case did not show fibrosarcomatous transformation or local recurrence prior to metastasis 9 years later. In summary, it is important to consider the potential for metastases years after a nonrecurring primary DFSP, despite its rarity. Cytologic features when complemented by ancillary studies and awareness of the patient's prior clinical history permit a confident diagnosis of metastatic DFSP by FNA. In addition, by confirming the characteristic translocation, tyrosine-kinase inhibitor imatinib can provide additional treatment options for unresectable metastatic DFSP.
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