Cytogenetic analysis of dermatofibrosarcoma protuberans

Clinical and histopathological analysis of 141 dermatofibrosarcoma protuberans in Korea: A comparative study according to trauma

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare fibrohistiocytic tumour of unknown pathogenesis with intermediate malignant potential. Although trauma has been hypothesized as a predisposing factor for DFSP development, clinicopathological characteristics of trauma-related DFSP have not been investigated.

OBJECTIVE

This study investigated the differences between trauma-associated DFSP and trauma-unrelated DFSP.

METHODS

Patients histopathologically diagnosed with DFSP from January 2000 to December 2019 at the Dermatology Department were included. Clinical, histopathological, prognostic features and trauma history were analysed.

RESULTS

We recruited 141 patients with DFSP (mean age, 36.1 years; male: female, 1:1.01). Recurrence and systemic metastasis were observed in 15.6% and 2.8% of patients, respectively. Older patients were likely to develop DFSP at the trauma sites more frequently on the face and lower legs. The active-growing lesions were more frequently associated with trauma-related DFSP. Multivariable logistic regression revealed that age at diagnosis (OR: 1.031; 95% CI: 1.004-1.059; p = 0.024) and tumour growth (OR: 3.336; 95% CI: 1.162-9.578, p = 0.025) were significantly associated with trauma-related DFSPs.

CONCLUSIONS

The age at diagnosis, lesion location and tumour growth were associated with DFSPs in this study. Analysis of DFSP with trauma history provides a deeper understanding of long-term trauma effects on sarcoma development.

Fine needle aspiration cytology of dermatofibrosarcoma protuberans arising in a burn scar

Tumours developing after a protracted period of time in burn scars are a notable complication with carcinomas forming a major share. The occurrence of burn scar sarcomas is scarce with dermatofibrosarcoma protuberans (DFSP) being an uncommon entity having only three prior reported cases. Herein we report a case of a 32-year-old male patient with a 5 year prior history of thermal burn who presented with an expanding painless swelling for 2 years in the right flank region, diagnosed as DFSP on fine needle aspiration cytology and subsequently confirmed on histopathology.

[Osteoid-forming bone tumors : Morphology and current translational cell biology]

Osteoid osteoma and osteoblastoma are the most important benign osteoid-forming tumors. They grow slowly and are well differentiated. Histologically, the tumor cells show no atypia and no increased mitoses. In typical cases, they can be clearly diagnosed. However, the rare cases on the dividing line between osteoblastoma and osteosarcoma are extremely problematic. In these cases, molecular genetic investigations should contribute to finding the correct diagnosis in the future.Juvenile highly malignant osteosarcoma is the most important malignant osteoid-forming tumor. About 40 years ago, neoadjuvant chemotherapy was introduced for the mostly young patients. This therapy highly significantly improved prognosis. However, a plateau phase was quickly reached and the last several decades have seen no further progress in conventional therapeutic approaches. There is no doubt that further progress can only be achieved on the basis of new molecular genetic and cell biological findings. The target-therapeutic strategies derived from these findings will be discussed in this review.The rare parosteal osteosarcoma and the even rarer periosteal osteosarcoma are mostly not highly malignant tumors that are located on the surface of bone. The parosteal osteosarcoma is usually G1 and the periosteal osteosarcoma G2. Occasionally, the differential diagnosis between a parosteal osteosarcoma and a fibrous dysplasia is difficult. In such rare cases, the detection of GNAS mutations in fibrous dysplasia can prove useful. In contrast to chondromas and chondrosarcomas, periosteal osteosarcomas do not contain IDH1 and IDH2 mutations.

Dermatofibrosarcoma protuberans with a novel COL6A3-PDGFD fusion gene and apparent predilection for breast

Dermatofibrosarcoma protuberans is a locally aggressive superficial mesenchymal neoplasm. It typically occurs in adulthood, and has been reported to have a slight male predilection. Tumors have a characteristic histopathologic appearance, including: storiform architecture, infiltrative "honeycomb" growth within subcutaneous adipose tissue, and immunoreactivity for CD34. Virtually all molecularly characterized cases to date have been found to harbor a COL1A1-PDGFB fusion product. Following identification of an index patient with a novel COL6A3-PDGFD fusion gene, we undertook a molecular investigation, using a combination of RNA sequencing and fluorescence in situ hybridization (FISH), to assess the prevalence of PDGFD rearrangement in dermatofibrosarcoma protuberans (N = 63). Three additional patients were found to have balanced PDGFD rearrangements. Interestingly, all 4 tumors arose on the breast of females. As a result, we subsequently examined 16 additional cases of primary breast dermatofibrosarcoma protuberans, identifying 2 additional tumors with PDGFD rearrangement. The morphology and immunophenotype of all 6 cases was analogous to those with the canonical COL1A1-PDGFB fusion; none of the cases showed fibrosarcomatous transformation. This study illustrates that the COL6A3-PDGFD fusion product is rare in dermatofibrosarcoma protuberans, and associated with an apparent predilection for breast. An awareness of this variant is important for pathologists, as it will not be detected using conventional reverse transcription polymerase chain reaction or FISH-based diagnostic assays for dermatofibrosarcoma protuberans.

Dermatofibrosarcoma Protuberans-Like Tumor With COL1A1 Copy Number Gain in the Absence of t(17;22)

A 57-year-old woman presented with a 3-year history of a progressive firm plaque on the right cheek. Skin biopsies revealed a bland, storiform, spindle-cell proliferation involving the deep dermis and subcutaneous fat. By immunohistochemistry, the tumor cells were diffusely positive for CD34 and caldesmon with multifocal reactivity for epithelial membrane antigen and focal, weak staining for smooth muscle actin. Retinoblastoma protein expression was not detectable in tumor cells by immunohistochemistry. An interphase fluorescence in situ hybridization analysis for platelet-derived growth factor B (PDGFB) gene rearrangement was negative. A single-nucleotide polymorphism array study detected 1) a gain of chromosome segment 17q21.33-q25.3 which overlapped the entire COL1A1 gene with a breakpoint at 17q21.33, approximately 250 Kb centromeric to the 3' end of COL1A1 gene, 2) several segmental gains on chromosome 11, and 3) an RB1 gene locus with normal copy number and allele frequency. Although the current case resembles dermatofibrosarcoma protuberans, it is unique in that it demonstrates a copy number gain of chromosome 17q in the absence of fusion of COL1A1 and PDGFB genes and an unusual immunohistochemical staining profile. The morphologic and molecular findings suggest a novel molecular variant of dermatofibrosarcoma protuberans not detectable with standard fluorescence in situ hybridization for PDGFB rearrangement. This variant appears to respond to imatinib after 9 months of follow-up.

Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans (DFSP) is a rare superficial soft tissue sarcoma. Its rarity precludes large prospective studies. Clinical diagnosis requires an high index of suspicion. Effective management requires an appreciation of tumor biology and the nature of the characteristic infiltrative growth pattern. DFSP tends to recur locally, with a low risk of dissemination. Aggressive surgical resection with widely negative margins is essential to management. Radiotherapy may be indicated in special circumstances. Understanding the molecular pathogenesis has resulted in use of tyrosine kinase inhibitor therapy for patients with locally advanced disease or in metastatic disease. DFSP patients require long-term follow-up.

Dermatofibrosarcoma protuberans: from translocation to targeted therapy

Dermatofibrosarcoma protuberans (DFSP), the most common dermal sarcoma, is a low-grade, slow growing fibroblastic malignant neoplasm that most frequently affects middle aged adults and is characterized by a high local recurrence rate and a low propensity for metastasis. Wide surgical resection or Mohs micrographic surgery (MMS) are the preferred approaches for localized disease, while radiation therapy is warranted for inoperable disease or for cases with positive margins where re-excision is not possible. DFSP is generally regarded as refractory to conventional chemotherapy. Treatment options for systemic disease were limited until the discovery of a unique translocation, t(17;22)(q22;q13) (COL1A1;PDGFB) found in a majority of cases. In recent years, imatinib, a PDGFβR, ABL and KIT inhibitor, has revolutionized systemic therapy in DFSP. In this review, we summarize the epidemiological, clinical, histological and genetic characteristics of DFSP and update the readers on its current management.

Current treatment options for dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans (DFSP) is rare, infiltrating dermal neoplasm, characterized by indolent growth and low probability of metastases. The critical event in DFSP development is the rearrangement of chromosome 17 and 22, leading to transcriptional up-regulation of platelet-derived growth factor, providing an autocrine and/or paracrine stimulus. The cornerstone of treatment for localized DFSP is complete surgical resection with microscopically negative margins. Adjuvant radiotherapy is suggested in cases of positive margins when re-excision is not feasible. The first effective systemic therapy in DFSP introduced into clinical practice was imatinib, demonstrating dramatic activity in advanced cases. Current results indicate that some DFSP patient initially evaluated as unresectable/metastatic or necessitating mutilating surgery turned resectable after imatinib therapy and this rational approach leading to complete remission maybe potentially curative. The clinical experience with other tyrosine kinase inhibitors is limited and imatinib remains the gold standard treatment of locally unresectable/metastatic DFSP. This review summarizes state of the art and perspectives on the DFSP management.

Dermatofibrosarcoma protuberans: a study of clinical, pathologic, genetic, and therapeutic features in Korean patients

PURPOSE

Dermatofibrosarcoma protuberans (DFSP) carries a translocation resulting in the collagen type I alpha 1 (COL1A1)-platelet-derived growth factor beta (PDGFB) fusion gene, which is responsible for PDGFB activation. The purpose of this study is to evaluate the clinicopathological, genetic, and therapeutic features of DFSP in Korean patients.

MATERIALS AND METHODS

Clinicopathological features of 37 patients with DFSP were reviewed. Multiplex reverse transcriptase-polymerase chain reaction (PCR) was carried out in 16 patients using formalin-fixed, paraffin-embedded tissues and specific primers for COL1A1 and PDGFB.

RESULTS

The mean age of 37 patients was 37.4 years old. The most common tumor location was the trunk. All patients were treated primarily with surgery: 34 (91.7%) cases with Mohs micrographic surgery (MMS) and 3 (8.3%) cases with wide local excision. The median follow-up time was 33.7 months. Two patients, one in each treatment group, demonstrated local recurrence during the follow-up period. The COL1A1-PDGFB fusion gene was expressed in 14 (87.5%) cases, demonstrated by reverse transcriptase PCR analysis. No association was found among the different COL1A1-PDGFB fusion transcripts, the various histological subtypes and clinical features.

CONCLUSION

Our results support the effectiveness of MMS in treating DFSP. The COL1A1-PDGFB fusion transcript was observed in 87.5% of patients. Therefore, COL1A1-PDGFB is a useful and accurate tool in diagnosing DFSP in Koreans.

[Dermatofibrosarcoma protuberans: report of 38 cases]

Le dermatofibrosarcome protubérans de Darier et Ferrand est une tumeur cutanée rare. Le but de cette étude est de décrire les aspects épidémiologiques, cliniques, histologiques, thérapeutiques et évolutifs avec comparaison aux données de la littérature. Il s'agissait d'une étude rétrospective sur 10 ans à propos de 38 cas de dermatofibrosarcome de Darier et Ferrand pris en charge à l'Institut National d'Oncologie. Les données épidémiologiques, diagnostiques, thérapeutiques et évolutives ont été recueillies à partir des dossiers cliniques des patients et rapportées sur une fiche préétablie. L’âge médian des patients était de 41,5 ans. Tous les patients avaient une preuve histologique de dermatofibrosarcome. Seulement 30 patients ont été traités à l'Institut National d'Oncologie. L'exérèse chirurgicale de la tumeur était large, avec des marges de sécurité de 6-10 cm chez 6 patients (20%), 5 cm chez 16 patients (53%), 2-3 cm chez 4 patients (13%). En profondeur, l'exérèse emportait une barrière anatomique saine. 5 malades ont bénéficié d'une radiothérapie externe avec une dose médiane de 59,5 Gy. Le recul médian était de 64,4 mois (28- 138 mois). Le dermatofibrosarcome protubérans de Darier et Ferrand est une tumeur se distinguant par son évolution lente, son agressivité locale, son haut pouvoir de récidive et la rareté des métastases. Le traitement consiste en une exérèse large et profonde. Le pronostic dépend essentiellement de la qualité de l'exérèse initiale chirurgicale. La série étudiée présente des similitudes épidémiologiques, cliniques, et thérapeutiques avec les données de la littérature.

Fibrosarcoma: a review and update

Adult fibrosarcoma, defined by the World Health Organization as a 'malignant neoplasm composed of fibroblasts with variable collagen production and, in classical cases, a "herringbone" architecture', is a very rare soft tissue sarcoma. Once considered the most common adult sarcoma, the incidence of adult fibrosarcoma has declined dramatically over the past several decades. This is due to (i) evolution in the classification of soft tissue tumours (ii) recognition of clinically, morphologically and genetically distinctive subtypes of fibrosarcoma and (iii) increased understanding of the many other mesenchymal and non-mesenchymal tumours that may mimic fibrosarcoma. This review article will summarize the current state of our knowledge about strictly defined adult fibrosarcoma and discuss important entities in its differential diagnosis, including various fibrosarcoma variants, monophasic synovial sarcoma and other potential mesenchymal and non-mesenchymal mimics.

Advances in molecular characterization and targeted therapy in dermatofibrosarcoma protuberans

The molecular pathogenesis of dermatofibrosarcoma protuberans (DFSP) involves distinctive rearrangement of chromosomes 17 and 22 leading to formation of the COL1A1-PDGFB fusion gene. The knowledge of molecular events underlying development of DFSP resulted in the implementation of targeted therapy with imatinib—a tyrosine kinase inhibitor (TKI), to the clinical practice. The striking efficacy of imatinib in advanced cases of DFSP has been demonstrated in a few clinical trials. Thus, imatinib is currently considered the gold standard in the treatment of inoperable and/or metastatic and/or recurrent cases of DFSP. Therapy with imatinib may potentially facilitate resection or decrease possible disfigurement related to radical surgical procedure. Following partial response on imatinib significant percentage of patients may be rendered free of the disease by surgery of the residual tumor.

Response of malignant scalp dermatofibrosarcoma to presurgical targeted growth factor inhibition

Dermatofibrosarcoma protuberans (DFSP) is an uncommon, locally aggressive, malignant cutaneous tumor that sparingly presents on the scalp. Dermatofibrosarcomas often result from the formation of a fusion oncogene on translocated or supernumerary ring chromosomes 17 and 22, causing the overexpression of PDGFRβ driven by the COL1A1 promoter. Because of uncertainty surrounding appropriate treatment of aggressive scalp DFSP, the authors performed an extensive review of the available data from a MEDLINE (Ovid) search to describe the clinical presentation and treatment options for this rare tumor. Their search identified 39 different cases, including the illustrative case presented in this study.

Adjuvant therapy for this malignant lesion is not universally established in the literature. In the present case, the authors successfully treated a locally invasive scalp DFSP with presurgical therapy that specifically inhibited the PDGFβ receptor. Imatinib significantly shrank the DFSP tumor mass, reduced hypervascularity, reduced metabolic activity on PET scanning, and permitted a safe gross-total resection. Although wide excision and Mohs micrographic surgery remain the standard surgical treatments for DFSP, the authors illustrate that presurgical chemotherapeutic treatment by imatinib provides a critical adjunct to traditional therapy.

Plaque-like CD34-positive dermal fibroma ("medallion-like dermal dendrocyte hamartoma"): clinicopathologic, immunohistochemical, and molecular analysis of 5 cases emphasizing its distinction from superficial, plaque-like dermatofibrosarcoma protuberans

Medallion-like dermal dendrocyte hamartoma (DH) and superficial (plaque-like) dermatofibrosarcoma protuberans (DFSP) are CD34-positive dermal neoplasms with overlapping clinicopathologic features. We analyzed the clinical, histomorphologic, and molecular criteria of 5 DH and 7 DFSP to delineate diagnostically relevant differences between incipient dermal DFSP and its benign look-alike, DH. We expand the clinical and histologic spectrum of DH. As medallion-like dermal DH is neither of dermal dendrocyte lineage nor a genuine hamartoma, we propose instead the descriptive term of plaque-like CD34-positive dermal fibroma (PDF). Both PDF/DH and DFSP presented as slightly pigmented and indurated plaques on neck, trunk, and extremities. Histologically, DFSP was characterized either by horizontally oriented spindle cell fascicles or by diffusely arranged fibroblasts within a slightly myxoid stroma in the upper two-thirds of the dermis, whereas PDF/DH presented with a cellular band-like fibroblastic proliferation mostly in the papillary and adjacent upper reticular dermis. Only one congenital PDF/DH in a 9-year-old boy extended into the septa of the subcutaneous fat. Formalin-fixed paraffin-embedded archival tissue was used for detection of the COL1A1-PDGFB gene rearrangement by multiplex reverse transcription-polymerase chain reaction (RT-PCR) and by dual color fusion fluorescence in-situ hybridization (FISH). Archival blocs older than 4 years did not yield amplifiable RNA because of RNA degradation, whereas FISH analysis was feasible in all investigated cases. FISH analysis revealed COL1A1-PDGFB gene rearrangement in all DFSP cases (n=7), whereas RT-PCR could detect the COL1A1-PDGFB fusion transcript only in 1 DFSP. Two cases were negative. In 4 archival cases with storage between 4.5 and 12 years, RNA had been degraded making these cases unsuitable for RT-PCR. In PDF/DH, both RT-PCR and FISH analysis did not reveal any evidence of COL1A1-PDGFB gene rearrangement. We show that PDF/DH and superficial (plaque-like) DFSP, subtle clinicopathologic differences notwithstanding, are morphologic look-alikes that can be kept apart by molecular studies of the COL1A1-PDGFB gene fusion. For the detection of the COL1A1-PDGFB gene rearrangement in diagnostically difficult cases, RT-PCR and FISH analysis are reliable and helpful diagnostic tools. In archival formalin-fixed paraffin-embedded tissue, however, FISH analysis is more robust and exhibits a higher clinical sensitivity than RT-PCR.

Dermatofibrosarcoma protuberans arising from a burn scar

Malignant neoplasms arising in burn scars are well known. In previous literature, 25 cases of burn scar sarcomas were reported. However, dermatofibrosarcoma protuberans is very rare and only two cases have been reported. A 43-year-old Korean man presented with multiple erythematous clustered plaques and nodules and a skin-colored subcutaneous mass on the chest after a severe burn injury at the age of 8 years. A biopsy specimen revealed dermatofibrosarcoma protuberans. The tumor was excised widely to include the surrounding burn scar. Herein, we report this third case of dermatofibrosarcoma protuberans arising from a burn scar.

Giant cell fibroblastoma: an update and addition of 86 new cases from the Armed Forces Institute of Pathology, in honor of Dr. Franz M. Enzinger

A quarter of a century ago at the International Academy of Pathology in Boston, Mass, Drs Enzinger and Shmookler's seminal abstract on giant cell fibroblastoma (GCF) included 20 GCFs on the back and thigh of mostly male children. These tumors involved dermis and subcutis, and had parallel fascicles of wavy uniform spindled cells with wiry collagen, dense sclerosis, and gaping spaces with scattered and rimming pleomorphic giant cells. EM suggested fibroblastic phenotype. All cases had benign behavior, but almost half recurred. The caveat was mistaking this tumor for a malignancy. In 1989, Drs Enzinger, Shmookler, and Weiss published this abstract as 28 cases from the AFIP (1960-1981), including 4 adults up to 55 years old. They proposed a relationship of this childhood tumor to dermatofibrosarcoma protuberans (DFSP). Since these original descriptions of GCF, there has been additional immunohistochemical and molecular support for a relationship between DFSP and GCF. We reviewed additional AFIP cases of GCF since 1981, in honor of Dr Enzinger. These new cases included 60 males and 26 females, whose ages ranged from 6 months to 62 years (median, 6 years; 62%, younger than 10 years; 77%, younger than 20 years; and only 10 patients were older than 40 years). Thirty-nine GCF cases with evaluable epidermis were observed to be protuberant, one with superficial ulceration. Most cases were dermal and subcutaneous, 3 purely dermal, and 5 involved superficial skeletal muscle. Almost all cases demonstrated a honeycomb pattern, and several, a parallel pattern of infiltration. Several cases spared adnexa. Pure GCF areas ranged from solid and collagenized to angiectoid and myxoid, the latter with small to large cystlike spaces. Most cases were relatively hypocellular, except one case with more atypia and mitotic activity. GCF demonstrated myoid whorls in 2 cases, a feature previously described in DFSP. Most remarkable is the peculiar perivascular lymphocytes in an onionskin pattern in GCF, not observed in DFSP. Furthermore, histologic intralesional hemorrhage seems to be common in GCF, particularly near the fascia. Fourteen of our 86 cases demonstrated 5% to 70% (median, 20%) dense nongiant cell storiform areas, interpreted as hybrid GCF-DFSP. Three of these cases demonstrated hypercellular DFSP. One hybrid case had fibrosarcomatous transformation. Two cases of pure GCF recurred as a hybrid tumor with DFSP areas, one of these with hypercellular DFSP. In all but one case, the DFSP was adjacent to GCF with an abrupt transition. Most cases studied were positive for CD34 (more intense in DFSP than relatively hypocellular GCF areas) and negative for smooth muscle actin, desmin, HMB-45, keratin, and S100 protein. GCF is exactly clinically and morphologically the same as Dr Enzinger and colleagues originally described it. Additional observations of marked perivascular and onionskin-like chronic inflammation and consistent hemorrhage may aid in the diagnosis of this previously well-described tumor. Collectively, we now have even more convincing morphologic, immunophenotypic, and molecular evidence that GCF is on a spectrum with DFSP.

Dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans (DFSP) is a soft tissue neoplasm of intermediate malignancy that is initially localized to the skin from where it can invade deep structures (fat, fascia, muscle and bone). It is the most frequent fibrohistiocytic tumor, comprising approximately 1.8 % of all soft tissue sarcomas and 0.1 % of all cancers. It has an estimated incidence of 0.8-5 cases per one million persons per year. Treatment of localized disease consists in complete surgical excision of the lesion by conventional surgery with wide margins (>3 cm) or by micrographic Mohs surgery. Although the cases of metastatic DFSP do not reach 5 % of the total, almost all of them appear after previous local relapses. The prognosis for metastatic cases is very poor with a survival of less than 2 years following detection of metastatic disease. Patients with locally advanced DFSP are not candidates for an initial radical surgical therapy therefore neoadyuvant treatment is required prior to surgery in order to reduce tumor burden. In this regard, chemotherapy and radiotherapy have not been highly efficacious so it is necessary to consider new alternatives. The demonstration of the oncogenic power of the translocation COL1A1-PDGFB in DFSP has allowed the successful introduction of drug therapy with antagonists of the PDGFB receptor for metastatic or locally advanced cases.

Transformed dermatofibrosarcoma protuberans: real time polymerase chain reaction detection of COL1A1-PDGFB fusion transcripts in sarcomatous areas

BACKGROUND

Recent cytogenetic studies have shown that reciprocal translocation t (17;22)(q22;q13) and a supernumerary ring chromosome derived from the translocation r(17;22) are highly characteristic of dermatofibrosarcoma protuberans (DFSP). The chromosomal rearrangements fuse the collagen type Ialpha1 (COL1A1) and the platelet-derived growth factor B-chain (PDGFB) genes. The COL1A1-PDGFB fusion transcript has been shown not only in conventional DFSP but also in a small series of DFSP with fibrosarcomatons areas (DFSP-FS) using reverse transcriptase-based conventional polymerase chain reaction. Nothing is known about the status of the COL1A1-PDGFB chimaeric gene in the pleomorphic areas of DFSP-PleoSarc (formerly known as DFSP-malignant fibrous sarcoma).

AIMS

To show the COL1A1-PDGFB fusion transcript in transformed malignant fibrous histiocytoma.

METHOD

A real-time polymerase chain reaction assay for the COL1A1-PDGFB fusion transcript in a series of DFSP containing sarcoma was conducted to determine whether the chimaeric gene could be identified in both components of DFSP-FS and DFSP-PleoSarc. Eight cases were analysed.

RESULTS

In seven cases, transcriptable RNA was detected, and in these cases, translocations were found between COL1A1 and PDGFB genes involving exons 27, 32, 34, 40 and 47 of the COL1A1 gene and exon 2 of the PDGFB gene.

CONCLUSIONS

From a diagnostic aspect, this assay can be particularly useful in confirming the diagnosis of sarcomatous DFSP. On the other hand, the COL1A1-PDGFB fusion gene was shown in three cases of DFSP containing pleomorphic sarcoma, which supports the theory of the common histogenesis.

Burn scar neoplasms: a literature review and statistical analysis

BACKGROUND

Although squamous cell carcinoma (SCC) is the most common burn scar neoplasm, other neoplasms have also been reported.

OBJECTIVE

To compile the burn scar neoplasm cases in the literature and to analyze their frequency and demographic characteristics.

MATERIALS AND METHODS

Cases were obtained through literature searches.

RESULTS

There were 412 cases gleaned from 146 articles between 1923 and 2004. Seventy-one percent (293) of the tumors were squamous cell carcinoma, 12% (48) were basal cell carcinoma (BCC), 6% (23) were melanoma, 5% (21) were sarcoma, 4% (16) were other neoplasms, 1% (6) were squamo-basal cell carcinoma, and 1% (5) squamous cell-melanoma. The mean age at tumor diagnosis was 50 years, the mean age at the time of burn injury was 20 years, the mean latency interval was 31 years. Only 5% of the reported cases were excised and grafted at the time of injury (p<0.001). BCC occurred at a significantly later age compared to SCC and sarcoma groups (p<0.02) and had a shorter latency period compared to SCC and sarcoma groups (p<0.004) and melanoma (p<0.008). Local recurrence was present in 16% of the cases, while regional lymph node involvement was seen in 22% of the cases and distant metastases was present in 14% of the patients. The mortality rate was 21%.

CONCLUSIONS

Although the main burn scar neoplasm was SCC, other neoplasms contributed to the morbidity and mortality of burn patients. Excision and grafting of deep burns, and close follow-up of non-healing ulcerated burn scars is essential for the prevention and early detection of burn scar neoplasms.

Cutaneous and Subcutaneous Fibrohistiocytic Tumors of Intermediate Malignancy

The fibrohistiocytic tumors of intermediate malignancy are uncommon mesenchymal tumors, which typically occur in the skin and subcutis and which may pose significant problems for the dermatopathologist. This article reviews the clinical, histopathologic, and genetic features of dermatofibrosarcoma protuberans, giant cell fibroblastoma, angiomatoid (malignant) fibrous histiocytoma, plexiform fibrous histiocytoma, and soft tissue giant cell tumor (of low malignant potential). The differential diagnosis of these tumors with a variety of benign and fully malignant cutaneous soft tissue neoplasms is discussed.

Dermatofibrosarcoma protuberans arising from a burn scar of the axilla

It is well-known that the development of a malignant tumor in a chronic burn scar is one of the long-term complications of a severe burn. Most of these tumors are squamous cell carcinomas, and sarcomas are much rarely seen in chronic burn scars. In the previous literature, 24 cases of burn scar sarcomas were reported. The authors report the second case of dermatofibrosarcoma protuberans arising in a chronic, severe burn scar. A 68-year-old woman with a reddish tumor in the right axilla was referred to the authors' hospital. The patient had sustained severe burns in the right axilla, upper arm, and trunk at the age of 6 years. A biopsy specimen revealed dermatofibrosarcoma protuberans. There was no evidence of distant metastasis. The tumor was excised widely to include the surrounding burn scar. Two years after the operation, there was no evidence of tumor recurrence. As surgeons, we should recognize the possibility of the occurrence of various malignant tumors including sarcomas on burn scars.

Gene expression patterns and gene copy number changes in dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans (DFSP) is an aggressive spindle cell neoplasm. It is associated with the chromosomal translocation, t(17:22), which fuses the COL1A1 and PDGFbeta genes. We determined the characteristic gene expression profile of DFSP and characterized DNA copy number changes in DFSP by array-based comparative genomic hybridization (array CGH). Fresh frozen and formalin-fixed, paraffin-embedded samples of DFSP were analyzed by array CGH (four cases) and DNA microarray analysis of global gene expression (nine cases). The nine DFSPs were readily distinguished from 27 other diverse soft tissue tumors based on their gene expression patterns. Genes characteristically expressed in the DFSPs included PDGF beta and its receptor, PDGFRB, APOD, MEOX1, PLA2R, and PRKCA. Array CGH of DNA extracted either from frozen tumor samples or from paraffin blocks yielded equivalent results. Large areas of chromosomes 17q and 22q, bounded by COL1A1 and PDGF beta, respectively, were amplified in DFSP. Expression of genes in the amplified regions was significantly elevated. Our data shows that: 1) DFSP has a distinctive gene expression profile; 2) array CGH can be applied successfully to frozen or formalin-fixed, paraffin-embedded tumor samples; 3) a characteristic amplification of sequences from chromosomes 17q and 22q, demarcated by the COL1A1 and PDGF beta genes, respectively, was associated with elevated expression of the amplified genes.

Genetics of dermatofibrosarcoma protuberans family of tumors: from ring chromosomes to tyrosine kinase inhibitor treatment

Dermatofibrosarcoma protuberans (DP) is a rare, slow-growing, infiltrating dermal neoplasm of intermediate malignancy, made up of spindle-shaped tumor cells often positive for CD34. The preferred treatment is wide surgical excision with pathologically negative margins. At the cytogenetic level, DP cells are characterized by either supernumerary ring chromosomes, which have been shown by using fluorescence in situ hybridization techniques to be derived from chromosome 22 and to contain low-level amplified sequences from 17q22-qter and 22q10-q13.1, or t(17;22), that are most often unbalanced. Both the rings and linear der(22) contain a specific fusion of COL1A1 with PDGFB. Similar to other tumors, the COL1A1-PDGFB fusion is occasionally cryptic, associated with complex chromosomal rearrangements. Although rings have been mainly observed in adults, translocations have been reported in all pediatric cases. DP is therefore a unique example of a tumor in which (i) the same molecular event occurs either on rings or linear translocation derivatives, (ii) the chromosomal abnormalities display an age-related pattern, and (iii) the presence of the specific fusion gene is associated with the gain of chromosomal segments, probably taking advantage of gene dosage effects. In all DP cases that underwent molecular investigations, the breakpoint localization in PDGFB was found to be remarkably constant, placing exon 2 under the control of the COL1A1 promoter. In contrast, the COL1A1 breakpoint was found to be variably located within the exons of the alpha-helical coding region (exons 6-49). No preferential COL1A1 breakpoint and no correlation between the breakpoint location and the age of the patient or any clinical or histological particularity have been described. The COL1A1-PDGFB fusion is detectable by multiplex RT-PCR with a combination of forward primers designed from a variety of COL1A1 exons and one reverse primer from PDGFB exon 2. Recent studies have determined the molecular identity of "classical" DP, giant cell fibroblastoma, Bednar tumor, adult superficial fibrosarcoma, and the granular cell variant of DP. In approximately 8% of DP cases, the COL1A1-PDGFB fusion is not found, suggesting that genes other than COL1A1 or PDGFB might be involved in a subset of cases. It has been proposed that PDGFB acts as a mitogen in DP cells by autocrine stimulation of the PDGF receptor. It is encouraging that inhibitory effects of the PDGF receptor tyrosine kinase antagonist imatinib mesylate have been demonstrated in vivo; such targeted therapies might be warranted in the near future for treatment of the few DP cases not manageable by surgery.

Overrepresentation of 17q22-qter and 22q13 in dermatofibrosarcoma protuberans but not in dermatofibroma: a comparative genomic hybridization study

Histopathological differentiation between dermatofibrosarcoma protuberans (DFSP) and dermatofibroma (DF) is often difficult, because both neoplasms share some clinical features and the presence of a storiform pattern. In the present study, we investigated the usefulness of comparative genomic hybridization (CGH) in the diagnosis of these entities by examining 12 DFSP and 12 DF cases. The most frequent DNA sequence copy number changes detected in 10 (83%) of 12 DFSP cases (mean, 1.9 aberrations/tumor; range, 0-3) consisted of gains of 17q22-qter (10 tumors), 22q13 (nine tumors), and 8q24.1-qter (three tumors). High-level amplification, which was detected in three tumors, was seen only in chromosome 17, with 17q23-q25 as the minimal common region. Loss of DNA sequences was not found in DFSP cases. In contrast, two (17%) of the 12 DF cases (mean, 0.5 aberrations/tumor; range, 0-4) showed DNA sequence copy number changes, although recurrent gains and losses and high-level amplifications were not observed. Gains were more common than losses in DF. Overrepresentation of 17q and 22q sequences was a common finding in DFSP but not in DF. Thus, CGH seems to be useful for distinguishing DFSP from DF in most cases.

Supernumerary ring chromosomes in dermatofibrosarcoma protuberans may contain sequences from 8q11.2-qter and 17q21-qter: a combined cytogenetic and comparative genomic hybridization study

Dermatofibrosarcoma protuberans (DFSP) presents with characteristic cytogenetic features such as reciprocal t(17;22)(q22;q13) or, more commonly, supernumerary ring chromosomes containing sequences from chromosomes 17 and 22. Here, we report the identification of a novel abnormality in a 43-year-old woman with DFSP. Cytogenetic analysis of tumor cells showed the presence of a supernumerary ring chromosome as the sole anomaly. Amplification of 8q11.2 approximately qter and 17q21 approximately qter sequences was confirmed by comparative genomic hybridization (CGH); the present case apparently lacked amplification of chromosome 22. To our knowledge, this is the first case indicating that the ring chromosome in DFSP is possibly associated with amplified material from chromosomes 8 and 17.

Spectral karyotyping reveals 17;22 fusions in a cytogenetically atypical dermatofibrosarcoma protuberans with a large marker chromosome as a sole abnormality

The presence of an extra ring chromosome containing material from 17q and 22q, or, less frequently, a t(17;22)(q22;q13), is a cytogenetic hallmark of dermatofibrosarcoma protuberans (DFSP). However, occasionally tumors with other, atypical karyotypes are encountered. We describe a case of recurrent DFSP without a ring chromosome or a t(17;22) on standard cytogenetic analysis. In all cells analyzed by G-banding, an additional, large marker chromosome was present as a sole abnormality. This chromosome apparently included chromosome 8 or the 8q arm, but the origin of its remaining part could not be determined with certainty. To characterize further the abnormal chromosome, we applied spectral karyotyping (SKY). SKY confirmed the presence of an extra chromosome 8 or arm 8q in the marker and showed that its remaining part was composed of segments from chromosomes 7, 17, 21, and 22, with two copies of a 17;22 fusion. Our results and the literature data suggest that, in addition to a specific 17;22 fusion, amplification of material from chromosomes 17, 22, 8, 5, 7, and 21 may play a role in DFSP development and/or progression. Furthermore, our case demonstrates the usefulness of SKY in detection of a diagnostically relevant 17;22 fusion in DFSP patients who have unusual karyotypic features.

Low grade fibromyxoid sarcoma. a further low-grade soft tissue malignancy characterized by a ring chromosome

Supernumerary rings in the context of a simple karyotype characterize several low-grade malignant tumors of soft tissue and bone. Low-grade fibromyxoid sarcoma is an uncommon low-grade sarcoma, the cytogenetics of which has not yet been reported. Here we describe the first molecular-cytogenetic characterization of a pulmonary metastasis of low-grade fibromyxoid sarcoma. The histology of the primary and recurrent tumors was consistent with the diagnosis of low-grade fibromyxoid sarcoma of the usual type, whereas the pulmonary metastasis was of the "giant rosettes" variant. Cytogenetic analysis revealed a ring chromosome. Because gain of material of chromosomes 7 and 16 was detected by CGH, the ring chromosome is assumed to be composed of material from these respective chromosomes.

The cytogenetic and molecular characterization of benign and malignant soft tissue tumors

Cytogenetic analyses of benign and malignant soft tissue tumors have led to the description of recurrent, specific, and even pathognomonic chromosomal translocations and/or other rearrangements in most types of soft tissue tumors. The consistent karyotypic rearrangements have provided critical diagnostic information in this group of neoplasms that often presents significant diagnostic challenges to the clinician and the pathologist. These findings have also been instrumental in the characterization of the abnormalities at the molecular level. Novel genes have been isolated from the translocation junctions and the mechanisms of their deregulation identified. This has increased our understanding of the histogenesis of these tumors, paved the way for the molecular diagnosis of many sarcomas, aided in directing therapy, and also provided important prognostic information.

Detection of COL1A1-PDGFB fusion transcripts in dermatofibrosarcoma protuberans by reverse transcription-polymerase chain reaction using archival formalin-fixed, paraffin-embedded tissues

The reciprocal translocation t(17;22)(q22;q13) and a supernumerary ring chromosome, r(17;22), derived from the translocation, have been shown to be highly characteristic of dermatofibrosarcoma protuberans (DFSP). Its consequence is a fusion of two genes, a collagen type I alpha 1 gene (COL1A1) and platelet-derived growth factor B-chain gene (PDGFB). The COL1A1-PDGFB fusion gene, is expected to be a diagnostic molecular assay. However, previous studies on this subject were mostly based on frozen tissue specimens or cultured tumor cells. In this present study, the investigators conducted a reverse transcription (RT)-polymerase chain reaction (PCR) assay to detect the COL1A1-PDGFB fusion transcripts using archival formalin-fixed, paraffin-embedded tumor specimens from 12 patients with DFSP. To amplify the fusion transcripts, a specific COL1A1 forward and PDGFB reverse primers were designed for single step PCR. The COL1A1-PDGFB fusion transcripts could be detected in 10 of 12 paraffin-embedded DFSP tumor specimens (83%). Subsequent sequence analysis using the PCR products confirmed that the detected messages were derived from gene fusions composed of PDGFB exon 2 and different regions of the COL1A1 gene (exon 8, 10, 22, 24, 32, 38, 45 or 46). Two samples of Bednar tumor included in this series also contained the fusion transcripts. In sample of DFSP with fibrosarcomatous transformation, the COL1A1-PDGFB could not be detected in the fibrosarcoma areas of the third recurrence, though the chimeric transcripts were identified in the ordinary DFSP areas of the first recurrence. No fusion transcripts could be amplified in non-DFSP lesions, including 10 dermatofibromas and 9 malignant fibrous histiocytomas. These results indicate that this molecular assay could be applied to archival formalin-fixed, paraffin-embedded tumor tissues as a diagnostic aid for DFSP.

A progression to dermatofibrosarcoma protuberans with a fibrosarcomatous component: a special reference to the chromosomal aberrations

Dermatofibrosarcoma protuberans (DFSP) with fibrosarcomatous areas (DFSP-FS) is differentiated from ordinary DFSP by its unfavourable prognosis. We carried out sequential analysis of numerical chromosomal abnormalities in two cases of DFSP during their progression to metastatic disease with FS areas (DFSP-M-FS). They were compared with nine cases of ordinary DFSP and three cases of DFSP-FS, but without metastases. Numerical chromosomal changes were examined by fluorescence in situ hybridization (FISH) using alpha-satellite centromeric probes for chromosomes 1, 8, 11 and 17. Numerical imbalances of chromosome 1 were not clarified. A gain of chromosome 8 was demonstrated in the two cases of DFSP-M-FS. A gain of chromosome 11 was observed in one of the two cases of DFSP-M-FS and in one case of DFSP-FS. A gain of chromosome 17 was demonstrated in both metastatic tumours and in recurrent tumours in two cases of DFSP-M-FS, in addition to two cases of DFSP-FS and four cases of ordinary DFSP with recurrent tumours or large tumours. This study raised the hypothesis that a gain of chromosome 17 developed in recurrent or large-sized DFSP, which occurs in high-risk groups with the possibility of a progression to FS.

A case of dermatofibrosarcoma protuberans with a ring chromosome 5 and a rearranged chromosome 22 containing amplified COL1A1 and PDGFB sequences

Dermatofibrosarcoma protuberans (DFSP) is a cutaneous tumour of borderline malignancy, the cytogenetic features of which include the translocation t(17;22)(q22;q13) or, more commonly, supernumerary ring chromosomes containing material from 17q22 and 22q13. These rearrangements result in the COL1A1/PDGFB fusion gene. Here, we describe a case of DFSP displaying a ring chromosome 5 together with a large marker chromosome composed of chromosome 22 alphoid DNA, material from distal 12q and amplified COL1A1 and PDGFB sequences. This is the first case of DFSP with multiple copies of COL1A1 and PDGFB not confined to ring chromosomes, showing that DFSP is similar to other borderline malignant mesenchymal tumours, where rings and giant markers are alternative vehicles for amplified material.

Malignant fibrous tumors

Dermatofibrosarcoma protuberans (DFSP), atypical fibroxanthoma (AFX), and malignant fibrous histiocytoma (MFH) are rare soft tissue sarcomas of intermediate to high-grade malignancy that the dermatologist must evaluate and treat. DFSP is a fibrohistiocytic tumor of intermediate malignancy characterized by aggressive local growth and propensity to recur after surgical excision. AFX is a superficial malignant tumor that arises on sun-exposed surfaces and is characterized by local aggressive behavior. MFH is the most aggressive of the fibrohistiocytic tumors with a high local recurrence rate and significant metastatic rate usually associated with a poor prognosis. This article reviews the epidemiology, pathogenesis, clinical presentation, histology, management, prognosis, and follow-up of these malignant tumors.