Conventional and contrast-enhanced ultrasound in the differential diagnosis of recurrent dermatofibrosarcoma protuberans and postoperative scar

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) has a high recurrence rate after resection. Because of the lack of specific manifestations, recurrent DFSP is easily misdiagnosed as post-resection scar. A few series have reported ultrasound findings of recurrent DFSP; moreover, the usefulness of contrast-enhanced ultrasound in differentiating recurrent DFSP has not been studied.

OBJECTIVE

We investigated conventional and contrast-enhanced ultrasound in the differential diagnosis of recurrent DFSP and post-resection scar.

METHODS

We retrospectively evaluated the findings of conventional and contrast-enhanced ultrasound in 34 cases of recurrent DFSP and 38 postoperative scars examined between January 2018 and December 2022.

RESULTS

The depth and vascular density of recurrent DFSP were greater than those of postoperative scars (P < 0.05). On gray-scale ultrasound, recurrent DFSP lesions were more commonly irregular, heterogeneous, and hypoechoic, with finger-like projections and ill-defined borders. Postoperative scar was more likely to appear as hypoechoic and homogeneous with well-defined borders (P < 0.05). On color Doppler ultrasound, recurrent DFSP was more likely to feature rich arterial and venous blood flow, and postoperative scar was more likely to display poor blood flow (P < 0.05). On contrast-enhanced ultrasound, recurrent DFSP was more likely to feature heterogeneous hyper-enhancement, and postoperative scar was more likely to display homogeneous iso-enhancement (P < 0.05). Recurrent DFSP presented a higher peak and sharpness than postoperative scar (P < 0.05).

CONCLUSION

Conventional and contrast-enhanced ultrasound produced distinct features of recurrent DFSP and post-resection scar, which could improve the accuracy of differential diagnosis.

Different sonographic presentations of dermatofibrosarcoma protuberans

BACKROUND

Dermatofibrosarcoma protuberans (DFSP) is a low-grade spindle cell sarcoma of fibroblastic origin. This tumor originates in the dermis and infiltrates the subcutaneous tissue. The highest incidence occurs in the third and fourth decades of life, affecting most frequently the trunk and proximal extremities. Ultrasound is performed in those cases where the clinical appearance of the lesion is not typical and when the physician wants to determine the extent and depth of the lesion.

MATERIAL AND METHODS

Retrospective analysis of the ultrasound and demographic findings of thirteen patients with DFSP.

RESULTS

13 patients, 8 females and 5 males, aged from 2 months to 58 years old. One patient with two different separated synchronous tumors. On ultrasonography they compromised the dermal hypodermal layers in 93% of the cases and 1 dermal lesion. The compromise reached the aponeurotic plane in two cases. The sized varied from 5 to 38 mm. They presented as a well-defined hypoechogenic nodule in seven cases (50%). In three cases (21%) they presented as a hypoechogenic infiltrate ill-defined border solid lesion; in two cases as a plaque ill-defined lesion, and two cases as a pseudonodular inflammatory lesion with irregular borders. All lesions appeared vascularized on color Doppler imaging.

CONCLUSION

DFSP is a low grade sarcoma of fibroblastic origin, that usually arises in the dermis and infiltrates the subcutaneous tissue. The clinical presentations are variable. On ultrasound we found different patterns: well-defined hypoechogenic solid nodule, hypoechogenic infiltrate ill-defined border solid lesion, plaque ill-defined lesion, and pseudonodular inflammatory lesion. It is important to know and recognize this suspicious different ultrasound presentations in order to recommend a histological study.

Integrating vascularity into the pattern classification of pilomatricomas on ultrasound provides a more competent approach for discriminative evaluation

BACKGROUND

Pilomatricoma has various manifestations on color Doppler ultrasound, and a differential diagnosis is challenging. The objective of this study was to investigate which characteristics of skin lesions on color Doppler ultrasound are effective in distinguishing pilomatricoma from epidermoid cyst and dermatofibrosarcoma protuberans.

MATERIALS AND METHODS

Records of patients with pilomatricomas (n = 63), epidermoid cysts (n = 76), and dermatofibrosarcoma protuberans (n = 19) who underwent color Doppler ultrasound evaluation and surgical excision were reviewed. The anatomical distribution and color Doppler ultrasound characteristics of these lesions were analyzed. The 63 pilomatricomas were categorized into five types based on their color Doppler ultrasound characteristics, and the roles of these five types in the differential diagnosis of the aforementioned diseases were studied.

RESULTS

Pilomatricomas, epidermoid cysts, and dermatofibrosarcoma protuberans exhibited some similar characteristics. Dominantly markedly hyperechoic or hyperechoic appearance, posterior acoustic shadowing, and the presence of vascularity were the major characteristics of pilomatricomas. The pilomatricomas could be categorized into five types, with type II having a diagnostic performance of sensitivity of 65.08%, specificity of 98.95%, area under the receiver operating characteristic curve (AUC) of 0.743, positive predictive value of 97.62%, and negative predictive value of 81.03% for the diagnosis of the aforementioned skin diseases.

CONCLUSION

A combination of dominantly markedly hyperechoic or hyperechoic appearance, posterior acoustic shadowing, and the presence of vascularity exhibits higher diagnostic performance for the differential diagnosis of pilomatricomas, epidermoid cysts, and dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans misdiagnosed as sebaceous adenoma and incompletely resected in a child: A case report

BACKGROUND

Dermatofibrosarcoma protuberans is extremely rare in children, making a correct diagnosis by clinicians is usually difficult due to its nonspecific manifestations, the recurrence of dermatofibrosarcoma protuberans after resection has always been a perplexing problem for clinicians. Ultrasound plays an irreplaceable role in the assessment of dermatofibrosarcoma protuberans, although there is a limitation in the diagnosis of the tumor.

CASE REPORT

A 10-year-old boy led by his parents sought for surgical treatment because of the growing mass. Physical examination and preoperative ultrasonography showed that the mass was clear, and the routine resection of mass was performed. Six days postoperatively, histopathological examination indicated that the mass was dermatofibrosarcoma protuberans, and the peripheral and deep resection margins were positive. The patient was informed that a second extended resection was required. The second postoperative pathology showed a negative margin, and the patient was discharged. Postoperative follow-up was assessed by ultrasound examination, and the patient had no abnormalities.

CONCLUSIONS

Dermatofibrosarcoma protuberans should be included in the differential diagnosis when the wide base subcutaneous lesion has suspicious features with high vascularity on ultrasound. If an ultrasound reveals a mass with abundant blood flow, clinicians should routinely perform the extended resection. Wide surgical excision may reduce the risk of reoperation and recurrence, and long-term follow-up is necessary to evaluate postoperative outcomes.

Machine learning-based radiomics analysis for predicting local recurrence of primary dermatofibrosarcoma protuberans after surgical treatment

BACKGROUND AND PURPOSE

Dermatofibrosarcoma protuberans (DFSP) is characterized by locally invasive growth patterns and high local recurrence rates. Accurately identifying patients with high local recurrence risk may benefit patients during follow-up and has potential value for making treatment decisions. This study aimed to investigate whether machine learning-based radiomics models could accurately predict the local recurrence of primary DFSP after surgical treatment.

MATERIALS AND METHODS

This retrospective study included a total of 146 patients with DFSP who underwent MRI scans between 2010 and 2016 from two different institutions: institution 1 (n = 104) for the training set and institution 2 (n = 42) for the external test set. Three radiomics random survival forest (RSF) models were developed using MRI images. Additionally, the performance of the Ki67 index was compared with the three RSF models in the external validation set.

RESULTS

The average concordance index (C-index) scores of the RSF models based on fat-saturation T2W (FS-T2W) images, fat-saturation T1W with gadolinium contrast (FS-T1W + C) images, and both FS-T2W and FS-T1W + C images from 10-fold cross-validation in the training set were 0.855 (95% CI: 0.629, 1.00), 0.873 (95% CI: 0.711, 1.00), and 0.875 (95% CI: 0.688, 1.00), respectively. In the external validation set, the C-indexes of the three trained RSF models were higher than that of the Ki67 index (0.838, 0.754, and 0.866 vs. 0.601, respectively).

CONCLUSION

Random survival forest models developed using radiomics features derived from MRI images were proven helpful for accurate prediction of local recurrence of primary DFSP after surgical treatment and showed better predicting performance than the Ki67 index.

Increased 68 Ga-FAPI Uptake in Dermatofibrosarcoma Protuberans

ABSTRACT

A 47-year-old woman presented with a 6-month history of palpable masses in the right hip. The patient was subsequently enrolled in our clinical trial of 68 Ga-FAPI PET/CT study on tumors. Intense 68 Ga-FAPI activities were noted in the right hip lesions, suggestive of malignancies. Pathological examination using tissue obtained on surgical resection rendered a diagnosis of dermatofibrosarcoma protuberans.

Micrographic Surgery Allows Fascia Preservation in Dermatofibro-sarcoma Protuberans

Removal of the deep fascia is recommended in therapy for dermatofibrosarcoma protuberans, but its necessity in the context of micrographic surgery is unclear. A retrospective clinicopathological analysis of 48 patients with dermatofibrosarcoma protuberans treated by micrographic surgery was performed, to determine in which tumours fascia preservation was feasible and safe. Histologically, 93% of tumours on the trunk and extremities and 14% of tumours in the head and neck region were fully located above the fascia. Localization on the head and neck was the only significant risk factor for tumour extension beyond the subcutis (p<0.001). Overall, 44% of tumours were completely excised above the fascia and 56% with deeper excisions. Two deeply infiltrating tumours (4%) on the head recurred, but in none of these lesions was the fascia spared. These results show that micrographic surgery allows fascia preservation in superficial tumours outside the head and neck region.

Magnetic resonance imaging features of dermatofibrosarcoma protuberans; what the surgeon should know: a case series

Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing, spindle cell neoplasm with low to intermediate grade malignant potential, commonly found in young and middle-aged adults, more in males than females. DFSP mostly originates in the dermis; rarely, it may be located in the deeper tissues without dermal involvement. Typically, DFSP appears as a multinodular mass, which then spreads into the subcutaneous tissues and muscle; it rarely dedifferentiates to high-grade fibrosarcoma, and more rarely, it may metastasise. We describe magnetic resonance imaging (MRI) features in three female patients with histologically proven DFSP and review the literature.

Recurrent occipital dermatofibrosarcoma protuberans tackled with wide local excision: A case report and current management

Dermatofibrosarcoma protuberans (DFSP) is a slowgrowing, locally invasive tumour of the dermis. It commonly presents in the trunks and proximal extremities but is seen to a lesser extent in the head and neck regions. We present a case report of a recurrent DFSP in a 48-year-old Iban woman at the occipital region. The patient underwent wide local excision and removal of outer table of cranium, dressing followed by split thickness skin graft. Histopathological examination confirmed dermatofibrosarcoma protuberans with clear lateral surgical margins and a deep margin of 0.5mm. She is currently undergoing radiotherapy and is planned for 50Grey 25cycles.

Dermatofibrosarcoma Protuberans: Computed Tomography and Magnetic Resonance Imaging Findings

The aim of this study was to analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of dermatofibrosarcoma protuberans (DFSP), with a view to improving the diagnosis of this kind of tumor. A total of 27 cases of histopathologically confirmed DFSP were analyzed retrospectively. Of these, 18 patients underwent a CT scan and 9 patients underwent an MRI. All patients underwent unenhanced and contrast-enhanced examinations; 1 patient underwent multiphrase CT enhancement examination. Imaging characteristics, including location, shape, size, number, edge, and attenuation or intensity of each lesion, both unenhanced and contrast enhanced, were analyzed. Of the 27 cases, 24 were solitary, 2 had 2 nodules, and 1 had multiple confluent tumors. The lesion with multiple confluent tumors was ill defined and irregular; the other lesions were oval or round, well-defined nodules or masses. The unenhanced CT images showed 19 homogenous isodense lesions. There was no calcification in any of the patients. The contrast-enhanced CT images showed intermediate and marked nonhomogeneous enhancement in 13 lesions, intermediate homogeneous enhancement in 4 lesions, and a mild heterogeneous enhancement in 2 lesions. MR T1-weighted images revealed 1 ill-defined and 9 well-defined homogeneous isointense lesions. T2-weighted images showed homogeneous hyperintensity to the muscles in 6 lesions, 3 mild hyperintense lesions with hypointense lesions, and 1 mixed, mild hyperintense and isointense lesion. Contrast-enhanced T1-weighted images demonstrated intermediate and marked nonhomogeneous enhancement in 9 lesions and intermediate homogeneous enhancement in 1 lesion. DFSP is characterized by a subcutaneous well-defined soft tissue nodule or mass on plain CT/MR scans, and shows intermediate-to-marked enhancement on contrast-enhanced CT/MR scans. The imaging findings for DFSP are nonspecific, but may help to define the diagnosis in an appropriate clinical setting.

Re-recurrent Dermatofibrosarcomaprotuberans of the chest wall

Dermatofibrosarcomaprotuberans is a rare, soft tissue tumour with high rate of recurrence. It is locally aggressive, with a low rate of metastasis. We describe the case of a 42 year old man who presented with a re-recurrent, large tumour situated on the anterior chest wall in the sternal region. We did a wide local excision and covered the resulting defect by using bilateral, pectoralis major myocutaneous flaps. Histopathology and immunohistochemical staining findings were consistent with the diagnosis of Dermatofibrosarcoma Protuberance. Post operatively the patient was treated with chemotherapy and radiotherapy.

Unusual subcutaneous localisation of a dermatofibrosarcoma protuberans of the female breast: a case report

Dermatofibrosarcoma protuberans (DFSP) is a slow growing soft tissue neoplasm of dermal fibroblastic origin characterised by local invasion and a high propensity for local recurrence. We report a 31-year-old woman with subcutaneous DFSP of the breast, which is an unusual localisation. Diagnostic work-up comprised clinical examination, mammography and ultrasound. Definitive diagnosis was not possible prior to histological analysis of the lesion. Wide excision of the tumour was performed, which is the therapy of choice in DFSP. Ultrasound played an important role in histological diagnosis before definitive surgery and might be helpful in follow-up of patients with DFSP of the breast.

Sonography of dermatofibrosarcoma protuberans of the groin

Dermatofibrosarcoma protuberans (DFSP) is an uncommon tumor that arises from the dermis of adults. Its malignant potential is considered to be intermediate. Because the diagnosis of DFSP can frequently be suspected on the basis of physical examination reports on its sonographic appearance are rare. We report a case that highlights the value of sonography in assessing the subcutaneous extent of DFSP.

Sonographic findings of dermatofibrosarcoma protuberans with pathologic correlation

OBJECTIVE

The purpose of this series was to describe the sonographic features of dermatofibrosarcoma protuberans (DP) and correlate them with the pathologic findings of this condition.

METHODS

The echogenicity and marginal contour of DP in 4 patients were observed on sonography, and these features were then correlated with the cellular components and histologic grading of pathologic specimens. Additionally, color Doppler sonography was conducted to evaluate the distribution of blood flow signals in the tumors.

RESULTS

All lesions were located in the subcutaneous fat layer, abutted against the skin, and had a wide base. Two of the cases of DP observed on the sonograms were hypoechoic, and 2 had mixed echogenicity; however, the mixed echogenic tumors were primarily echoic. The margin was focally lobulated but well defined in the hypoechoic tumors; however, the margin appeared as an irregular pseudopodialike protrusion in the mixed echogenic tumors. Color Doppler sonography showed 2 different blood flow patterns: 1 in which profuse blood flowed through the entire tumor and 1 in which only a small amount of blood flowed through the peripheral portions of the tumor. The 2 blood flow patterns were observed in 1 of each type of tumor. Pathologically, samples corresponding to hypoechoic DP were composed primarily of tumor cells, and samples corresponding to mixed echogenic DP were composed of tumor cells and fibrous tissues.

CONCLUSIONS

If a sonogram reveals an oval mass in the subcutaneous tissue that is abutting against the skin and has a focal lobulated margin with hypoechogenicity or an irregular margin with mixed echogenicity, a diagnosis of DP should be considered.

Biopsia selectiva de ganglio centinela en tumores cutáneos no melanoma

PURPOSE

To assess the feasibility of the Sentinel lymph node biopsy (SLNB) technique in cutaneous non-melanoma malignancies.

MATERIALS AND METHODS

Nine patients were retrospectively evaluated performing a scintigraphy with 99mTc-nanocolloid. On the day of the surgery, an initial dynamic study and static images were obtained. The first drainage station visualized was considered the sentinel node (SLN). The SLN position was marked on the skin and after a correct localization in the surgical field with a gamma probe the SLN was obtained. Patients of this study have been followed up for 8 to 48 months.

RESULTS

Lymphoscintigraphy detected the sentinel node in 88,8 % of our studies (the SLN was not observed in a patient with a Merkel's tumour on the back). The SLN was identified intraoperatively in those patients with positive imaging. Those cases without scintigraphic demonstrated migration were also not found intraoperatively. Histopathological analysis of the SLN showed non metastatic disease and none patient developed metastases or local recurrence in the monitoring period.

CONCLUSIONS

Sentinel node biopsy can be applied to certain cutaneous non-melanoma malignancies. In patients with unclear drainage and to avoid unnecessary lymphadenectomy, the technique offers clear advantages. In our study the SLN analysis was related to the clinical progress. A large number of patients should be examined to truly assess the benefit of this technique in this kind of malignancies and to determinate when the technique must be performed.

Metastatic Bednar tumor (pigmented dermatofibrosarcoma protuberans) with fibrosarcomatous change: a case report

Bednar tumor (pigmented dermatofibrosarcoma protuberans) is a variant of dermatofibrosarcoma protuberans (DFSP) that constitutes 5% of all DFSP and has a very low rate of distant metastases. We encountered a rare case of Bednar tumor with multiple different distant metastases. A 51-year-old man, who had had a history of mass resection in his left shoulder 4 years previously, was referred to our institution, complaining of a recurrence of the shoulder mass. The histological diagnosis of primary tumor was Bednar tumor, and he underwent resectional surgery for the recurrent lesion. A second local relapse, lung metastasis, retroperitoneal metastasis, and metastasis to the sigmoid colon have occurred. The recurrence lesion and all metastatic lesions were resected surgically. The histological features of all specimens showed fibrosarcomatous change. Seven months after the last surgical resection, the tumor recurred and the patient died of multiple abdominal metastases 10 years after the first surgical treatment.

Sustained complete remission of metastatic dermatofibrosarcoma protuberans with imatinib mesylate

Dermatofibrosarcoma protuberans (DFSP) is a soft tissue tumor which may recur locally and rarely causes metastases to vital organs. DFSPs have specific chromosomal abnormalities involving the platelet-derived growth factor beta-chain locus (PDGFB) which may render these tumors responsive to targeted therapy with the tyrosine kinase inhibitor imatinib mesylate. A patient with locally recurrent and metastatic DFSP resistant to first-line chemotherapy was treated with imatinib mesylate 400 mg/day. The tumor was examined by a novel fluorescence in situ hybridization (FISH) method for specific rearrangements of the PDGFB locus. The patient was followed for response and toxicity by physical examination and imaging studies. FISH revealed PDGFB rearrangement indicative of multiplication of the PDGFB fusion locus within a ring chromosome. Physical examination showed response within the first month of treatment, and subsequent computed tomography and fluorodeoxyglycose positron emission tomography documented complete response to imatinib therapy. Our patient is now in sustained complete remission for 20 months with minimal toxicity. We conclude that sustained complete remission of metastatic DFSP with specific FISH abnormalities involving the PDGFB locus can be obtained with imatinib mesylate with minimal toxicity for the patient.

Molecular targeting of platelet-derived growth factor B by imatinib mesylate in a patient with metastatic dermatofibrosarcoma protuberans

PURPOSE

Dermatofibrosarcoma protuberans is caused by activation of the platelet-derived growth factor B (PDGFB) receptor, a transmembrane tyrosine kinase. We investigated the response of dermatofibrosarcoma protuberans to the tyrosine kinase inhibitor imatinib mesylate.

PATIENTS AND METHODS

A patient with unresectable, metastatic dermatofibrosarcoma protuberans received imatinib mesylate (400 mg bid). Response to therapy was assessed by [18F]fluorodeoxyglucose (FDG) positron emission tomography, magnetic resonance imaging, and histopathologic and immunohistochemical evaluation.

RESULTS

The patient was treated for 4 months with imatinib mesylate. The hypermetabolic uptake of FDG fell to background levels within 2 weeks of treatment, and the tumor volume shrank by over 75% during the 4 months of therapy, allowing for resection of the mass. There was no residual viable tumor in the resected specimen, indicating a complete histologic response to treatment with imatinib mesylate.

CONCLUSION

Imatinib mesylate is highly active in dermatofibrosarcoma protuberans. The dramatic response seen in this patient demonstrates that inhibition of PDGFB receptor tyrosine kinase activity can significantly impact viability of at least one type of solid tumor.

Dermatofibrosarcoma protuberans. A rare case involving the pediatric foot

Dermatofibrosarcoma protuberans is a rare, slow-growing, locally destructive, intermediate-grade malignancy that originates in the dermal layer of the skin. Dermatofibrosarcoma protuberans rarely metastasizes and has a marked tendency to recur following local surgical excision. The lesion is found most commonly on the trunk, on the proximal aspect of both the lower and upper extremities, and in the head and neck region. Dermatofibrosarcoma protuberans occurs most commonly in people between the ages of 20 and 50. This article describes the clinical and pathologic features of this rare, malignant neoplasm and describes a rare case of dermatofibrosarcoma protuberans involving the pediatric foot.

Sarcomatous dermatofibrosarcoma protuberans metastasized to the lung: preservation of CD34 expression in tumor cells

A case of metastatic dermatofibrosarcoma protuberans (DFSP) in a 47-year-old woman is presented. Dermatofibrosarcoma protuberans occasionally recurs, but rarely metastasizes. The patient underwent local removal of the nuchal tumor by a general practitioner, followed by a rapid recurrence. She underwent total removal of the tumor and a diagnosis of spindle cell sarcoma was made after an incisional biopsy was performed. This lesion had both a typical DFSP-like area and a fibrosarcoma (FS)-like area. After 7 years, an abnormal lung shadow was observed and a segmental lung resection was performed. Histologically, the lung tumor was similar to the FS-like area in the nuchal tumor. Confirming CD34 expression in the tumor cells, this lung tumor was diagnosed as metastatic DFSP. Usually CD34 expression is unique to DFSP but almost negative in FS-like areas. In the present case, the FS-like area in the nuchal tumor showed decreased CD34 reactivity, as previously reported, but the FS-like area in the metastatic tumor still widely preserved CD34 expression. The presented case suggests that the FS-like area in DFSP is histogenetically different from typical FS or malignant fibrous histiocytoma.

[Large abdominal wall reconstruction by free flap after recurrence of a dermatofibrosarcoma protuberans]

Based on a case of recurrence of a dermatofibrosarcoma protuberans of the abdominal wall, the authors discuss the need for initial wide resection of this type of skin tumour and the possibilities of repair of extensive full thickness defects of the abdominal wall by means of a latissimus dorsi myocutaneous free flap.

Dermatofibrosarcoma protuberans. CT findings with pathologic correlation in 6 cases

PURPOSE

To characterize the CT findings of dermatofibrosarcoma protuberans.

MATERIAL AND METHODS

CT and pathologic specimens of 6 patients with dermatofibrosarcoma protuberans (5 in the trunk and 1 in the leg) were retrospectively reviewed.

RESULTS

CT clearly defined the tumors in the dermis and subcutaneous tissue with a characteristic, if not pathognomonic, protrusion. On postcontrast CT, 3 tumors showed marginal enhancement and central low density, while the others showed homogeneous enhancement. Pathologically, the marginal enhancement on CT corresponded to fibrosarcomatous changes, and the central low density to necrosis. The tumors with homogeneous enhancement had no sarcomatous changes.

CONCLUSION

CT allows detection and precise anatomic localization of dermatofibrosarcoma protuberans. Marginal enhancement with central low density on CT may suggest a relatively poor prognosis.

Dermatofibrosarcoma protuberans: radiologic appearance

OBJECTIVE

Dermatofibrosarcoma protuberans is a distinct clinicopathologic entity characterized by fibroblasts with a prominent storiform pattern. It accounts for about 6% of all soft-tissue sarcomas. The lesion is typically superficial, and the diagnosis can be suspected on the basis of the tumor's clinical appearance. Consequently, the imaging appearance of this entity is essentially unreported. Large lesions, however, can infiltrate the deep soft tissue and be confused with higher-grade sarcomas. We report the radiologic appearance in 11 cases of histologically proved dermatofibrosarcoma protuberans.

MATERIALS AND METHODS

The radiologic images of 11 patients who had histologically verified dermatofibrosarcoma protuberans were retrospectively studied. The patients included eight males and three females 9-47 years old (mean, 33 years). Each had a soft-tissue mass that had been present for a variable period, from 3 months to 23 years. CT scans were available for review in six cases, MR images in four, radiographs in nine, bone scintigrams in three, and arteriograms in three.

RESULTS

All lesions were unmineralized nodular masses involving the skin and subcutaneous adipose tissue. The size, in greatest dimension on imaging studies, was 3-22 cm. CT scans (six cases) showed a well-defined lesion with a distinct lobular or nodular architecture and tissue attenuation approximately equal to or greater than that of skeletal muscle. Moderate enhancement was seen on CT scans obtained after injection of contrast material. Arteriograms (three cases) showed mild to moderate hypervascularity. The MR appearance (four cases) was nonspecific; the lesions had prolonged T1 and T2 relaxation times. In one case, MR images showed multiple nodular lesions. Radiographs (nine cases) showed a soft-tissue mass or soft-tissue swelling without evidence of bone involvement or calcification. Bone scintigrams (three cases) showed increased accumulation of tracer.

CONCLUSION

The radiologic appearance of dermatofibrosarcoma protuberans is typically that of an unmineralized, nodular soft-tissue mass involving the skin and subcutaneous adipose tissue. CT scans or MR images are well suited to show this location, the relation of the lesion to underlying structures, and the distinct lobular or nodular architecture. Arteriograms will show mild to moderate hypervascularity and bone scintigrams will show increased accumulation of radiopharmaceutical.

Dermatofibrosarcoma protuberans of the toe. Findings on multiple imaging modalities

Dermatofibrosarcoma protuberans occurs early in life, is an unusual soft tissue tumor, and is uncommonly seen distal to knees. The authors present a rare case of dermatofibrosarcoma protuberans of the toe with different imaging modalities.