An Unusual Case of Cauliflower-like Tumor of Breast
Dermatofibrosarcoma protuberans (DFSP) is a rare type of malignant tumor that accounts for approximately 0.1% of all malignant tumors. This tumor is classified as a poorly to moderately differentiated tumor and primarily occurs in the superficial skin and subcutaneous tissue of the trunk. It is relatively uncommon in the breast, making this case particularly noteworthy. This article presents a detailed account of a 24-year-old female patient with DFSP of the breast, highlighting the clinical presentation, diagnostic process, imaging findings, pathological characteristics, and treatment options.
Clinical Presentation
The patient, a 24-year-old woman, was admitted to the Central Theater Command General Hospital of the Chinese People’s Liberation Army with a tumor in her left breast that had been discovered two years prior. Upon physical examination, a 6.0 cm × 5.0 cm tumor was observed in the upper quadrant of the left breast. The tumor was prominent in the skin and exhibited an inflamed, red appearance. In the lower quadrant of the same breast, a 4.0 cm × 5.0 cm mass was also noted. This mass was dark red, hard in texture, and showed no obvious tenderness. It exhibited moderate activity and had unclear boundaries with the surrounding tissues. The skin of the left breast appeared patchy, while the right breast showed no abnormalities, and no nipple inversion was observed.
Imaging Findings
Bilateral breast color Doppler ultrasonography revealed multiple cauliflower-like exophytic masses in the left breast. Specifically, a solid mass measuring 6.4 cm × 4.2 cm was observed in the upper quadrant of the nipple. This mass involved the subcutaneous tissue and skin layer, extending deep to the muscular layer. It had a smooth border and an irregular shape. The right breast showed an uneven parenchymal echo with a “leopard” pattern and visible patches. No hypoechoic areas of shape or strip were detected. In the bilateral axilla, several solid hypoechoic nodules with blurred boundaries and middle lymphatic hilum structures were observed. The left axillary nodule measured 1.4 cm × 0.5 cm, while the right measured 1.7 cm × 0.5 cm. Color Doppler flow imaging indicated abundant blood flow in the solid mass above the left breast papilla, while no abnormal blood flow signals were found in the right breast. Stellate blood flow signals were observed in the bilateral axillary hypoechoic nodules.
A chest CT plain scan revealed multiple irregular soft tissue masses in the left breast and left chest wall, measuring approximately 51 mm × 66 mm with clear margins. No consolidation was found in either lung, and the hilar bronchial openings were unobstructed. No enlarged lymph node shadows were observed in the mediastinum.
Pathological Examination
An ultrasound-guided biopsy under local anesthesia was performed, and the pathological findings were consistent with dermatofibrosarcoma protuberans. Immunohistochemical results showed positivity for vimentin, CD34, Nestin, and Ki67 (5%). Desmin, smooth muscular actin, CD31, and S-100 were negative. Beta-catenin was positive in the serum. The tumor cells were arranged in short bundles, closely packed in a spoke-like pattern, with long spindle nuclei and clear cytoplasm.
Discussion
Dermatofibrosarcoma protuberans is a malignant tumor that arises from the dermis and subcutaneous mesenchymal tissue. It is characterized by slow local growth and a high rate of local recurrence, although distant metastasis is rare. DFSP accounts for approximately 2% to 6% of soft tissue sarcomas and has an annual incidence of 0.8 to 4.5 cases per million. The disease predominantly affects individuals between the ages of 20 and 50, with a higher incidence in males than females. The tumor typically presents as a small nodule in its initial stage, growing slowly over several years to decades. However, rapid growth can occur as the disease progresses. DFSP most commonly occurs in the superficial skin and subcutaneous tissue of the trunk (50%-60%), followed by the limbs (20%-30%) and the head and neck (10%-15%). It is exceptionally rare in the breast.
The etiology of DFSP remains unclear. Some studies suggest that it may be related to the excessive proliferation of damaged tissues. For instance, a case of DFSP of the breast was reported in a patient with a history of breast trauma. However, the specific biological differences between DFSP occurring in the breast and other parts of the body have not been thoroughly studied and warrant further investigation.
Diagnostic Considerations
When a subcutaneous tissue-like round mass adjacent to the skin appears as a lobulated hypoechoic region or irregular mixed echoes on ultrasound, the possibility of DFSP of the breast should be considered. In this case, ultrasonography revealed that the mass involved the subcutaneous tissue and skin layer, extending deep to the muscular layer, with a smooth border and irregular shape. Abundant blood flow signals were observed in the solid mass above the left nipple. CT findings in DFSP typically show clear isodense or slightly hypodense shadows with uniform density and clear boundaries. In this patient, chest CT revealed irregular isodensity with a clear boundary, providing vital information for pre-operative evaluation.
Pre-operative imaging for DFSP primarily includes mammography, ultrasonography, CT, and magnetic resonance imaging. However, the final diagnosis depends on pathological examination. The epidermis of DFSP is often atrophic, and the dermis is composed of spindle-like fibroblasts of the same size. Tumor cells are densely packed and arranged in a radial or sheet-like pattern around the center. Tumor cells can invade subcutaneous tissue, interlobular septa, or muscular layers, forming honeycomb-like or multi-layered parallel arrangements. CD34 positivity is a hallmark of DFSP and was observed in this patient. Additionally, more than 90% of DFSP cases exhibit a translocation of chromosomes 17 and 22 (17;22), which could serve as a new diagnostic method.
Treatment Options
Tumor cells of DFSP are generally insensitive to chemotherapy, making radical surgical resection the first-line treatment. Surgical margins should be 3 to 5 cm away from the tumor tissue to reduce the risk of recurrence. The Mohs operation, which involves the sequential removal and microscopic examination of tissue layers, can also be performed to achieve negative margins and effectively reduce the recurrence rate. In this case, the patient underwent enlarged resection of the tumors after diagnosis. For patients with large tumors, negative margins, metastasis, or recurrence, adjuvant radiotherapy or imatinib mesylate, a tyrosine kinase inhibitor, can be used. Imatinib mesylate selectively inhibits the bcr gene (bcr/abl), stem cell factor receptor (Kit), the human CSF-1 receptor gene (c-FMS), Arg (abl-related gene), platelet-derived growth factor receptor A and B (PDGFRA and PDGFRB), preventing tyrosine kinase receptor phosphorylation, suppressing abnormal signaling pathways, and inhibiting the proliferation of DFSP.
Differential Diagnosis
Differential diagnosis is essential to distinguish DFSP from other breast tumors, such as fibroadenoma and phyllodes tumors. Fibroadenomas typically appear as round-like masses with smooth and sharp edges, sometimes showing calcification, good mobility, and no adhesion to the skin. Phyllodes tumors, on the other hand, are lobulated, smooth-edged, and highly dense masses, but the surface of the skin and subcutaneous fat remain relatively intact.
Conclusion
Breast dermatofibrosarcoma protuberans is a rare condition, and the case presented here involved a tumor measuring approximately 6.0 cm × 5.0 cm. The diagnosis was confirmed through imaging examination and ultrasound-guided puncture biopsy. Currently, surgical resection remains the preferred treatment for DFSP. This case underscores the importance of considering DFSP in the differential diagnosis of breast tumors, particularly when imaging findings suggest a lobulated hypoechoic region or irregular mixed echoes. Further research is needed to better understand the biological differences of DFSP occurring in the breast and to explore new diagnostic and therapeutic approaches.
doi.org/10.1097/CM9.0000000000000516
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