Question:
A 36-year-old female presents today for a slowly enlarging bump on her left breast that has been present for 3 years (pictured below).
It is not symptomatic and initially presented during pregnancy. Another provider thought it was a keloid however she has not had any surgery or trauma to this area. On exam, she has a firm ill-defined nodule with adjacent indurated plaque. You perform a biopsy of the lesion showing a spindle cell neoplasm that stains weakly positive with CD34+ consistent with a dermatofibrosarcoma protuberans. The pathologist notes that it is of the fibrosarcomatous type. After initial surgical removal with Mohs surgery, what is the best next step in workup?
Answer choices:
A. No further workup needed, discuss risk of local recurrence as metastasis of DFSP is extremely rare
B. CT of the chest
C. Colonoscopy
D. Mammogram
E. Cervical exam
Rationale: Dermatofibrosarcoma protuberans (DFSP) is a sarcoma typically observed in young or middle-aged individuals. Most have a translocation t(17;22) leading to PDGF-beta being constitutively activated by collagen T1A1. Clinically, these present as asymptomatic slow-growing reddish brown indurated plaques most commonly on the trunk or shoulder. DFSPs are locally very aggressive with an infiltrative growth pattern and high rate of local recurrence after surgery however treatment with Mohs micrographic surgery seems to have the lowest rate rate of local recurrence. DFSPs with fibrosarcomatous change (DFSP-FS) portend a worse prognosis.
Correct Answer: B. Chest CT
DFSP-FS is a more aggressive form of DFSP. A systemic review showed the risk of metastasis to be 14.4% in DFSP-FS compared to 1.1% in DFSP; similarly, local recurrence rates and death from disease were significantly higher in the fibrosarcomatous group. The most common site of distant metastasis appears to be the lung; other reported sites of metastasis include lymph node, bone, pancreas, and brain. NCCN guidelines recommend considering CT of the draining nodal basin and chest but do not specify the frequency of screening. For DFSP-FS, European consensus guidelines suggest baseline lymph node ultrasound, chest radiograph, abdominal US or MRI, and clinical exam every 6 months for 5 years with imaging examinations during the follow-up period. Interdisciplinary discussion on management with medical oncology can be helpful in this higher-risk subgroup.
Incorrect answers:
A. No further workup needed, discuss risk of local recurrence as metastasis of DFSP is extremely rare
Although this is generally a true statement for most patients with ordinary DFSP, the patient in the vignette has DFSP-FS which has a higher rate of local recurrence but more importantly distant metastasis and death. Appropriate risk stratification from a histopathologic standpoint is necessary to understand the potential burden of disease.
C. Colonoscopy, D. Mammogram, E. Cervical exam
DFSP-FS is an uncommon tumor with the lung being the most common site of metastasis. Mammography, cervical exam, and colonoscopy would not help screen for sites of metastasis. Although the risk of subsequent malignancy in patients with DFSP has been reported to be higher, this may be due to recall bias or more frequent physician visits in general; guidelines for screening of other malignancies do not differ for patients with history of DFSP.
Additional reading at Skin Cancer A Comprehensive Guide Chapter 13: Sarcomas
1. Liang CA, Jambusaria-Pahlajani A, Karia PS, Elenitsas R, Zhang PD, Schmults CD. A systematic review of outcome data for dermatofibrosarcoma protuberans with and without fibrosarcomatous change. J Am Acad Dermatol. 2014 Oct;71(4):781-6. doi: 10.1016/j.jaad.2014.03.018. Epub 2014 Apr 19. PMID: 24755121.
2. Jing C, Zhang H, Zhang X, Yu S. Dermatofibrosarcoma Protuberans: A Clinicopathologic and Therapeutic Analysis of 254 Cases at a Single Institution. Dermatol Surg. 2021 Feb 1;47(2):e26-e30. doi: 10.1097/DSS.0000000000002578. PMID: 32769521.
3. Hayakawa K, Matsumoto S, Ae K, Tanizawa T, Gokita T, Funauchi Y, Motoi N. Risk factors for distant metastasis of dermatofibrosarcoma protuberans. J Orthop Traumatol. 2016 Sep;17(3):261-6. doi: 10.1007/s10195-016-0415-x. Epub 2016 Jun 11. PMID: 27289468; PMCID: PMC4999380.
4. Saiag P, Grob JJ, Lebbe C, Malvehy J, del Marmol V, Pehamberger H, Peris K, Stratigos A, Middelton M, Basholt L, Testori A, Garbe C. Diagnosis and treatment of dermatofibrosarcoma protuberans. European consensus-based interdisciplinary guideline. Eur J Cancer. 2015 Nov;51(17):2604-8. doi: 10.1016/j.ejca.2015.06.108. Epub 2015 Jul 16. PMID: 26189684.
5. https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1430
6. Kurlander DE, Martires KJ, Chen Y, Barnholtz-Sloan JS, Bordeaux JS. Risk of subsequent primary malignancies after dermatofibrosarcoma protuberans diagnosis: a national study. J Am Acad Dermatol. 2013 May;68(5):790-6. doi: 10.1016/j.jaad.2012.10.040. Epub 2012 Dec 21. PMID: 23261548.