Clinicopathological and immunohistochemical study of 30 cases of post-radiation atypical vascular lesion of the breast

Contemporary diagnostic approach to atypical vascular lesion and angiosarcoma

Vascular neoplasms account for a substantial fraction of cutaneous mesenchymal tumors, spanning from clinically indolent benign lesions to highly aggressive malignancies. These neoplasms present a distinctive challenge in terms of their diagnostic histopathology, both because of the breadth of their morphological manifestations and because of the significant histological overlap between different entities, even benign and malignant ones. The post-radiotherapy setting is particularly problematic diagnostically, insofar as radiation exposure predisposes not only to secondary angiosarcoma, but also to atypical vascular lesion, a largely benign proliferation of cutaneous blood vessels typically affecting the breast. To address these challenges, we explore the clinical, histological, and molecular features of malignant vascular neoplasia, including primary and secondary subtypes, through the comparative lens of atypical vascular lesion. In addition to highlighting the key morphological indicators of malignancy in superficial vasoformative tumors, we offer an approach that integrates clinical characteristics and molecular genetic profiling to facilitate accurate classification. With this current knowledge as our foundation, we also look ahead in an effort to frame some of the key unanswered questions regarding superficial vascular malignancies and their natural history, clinical management, and molecular underpinnings.

Mesenchymal Tumors of the Breast: Fibroblastic/Myofibroblastic Lesions and Other Lesions

Mesenchymal breast tumors are a rare and diverse group of tumors that present some of the most challenging cases for multidisciplinary breast cancer teams. As a result of overlapping morphologies and a lack of large-scale studies on these tumors, practices are often heterogeneous and slow to evolve. Herein, we present a non-systematic review that focuses on progress, or lack thereof, in the field of mesenchymal breast tumors. We focus on tumors originating from fibroblastic/myofibroblastic cells and tumors originating from less common cellular origins (smooth muscle, neural tissue, adipose tissue, vascular tissue, etc.).

Radiation Induced Atypical Vascular Lesion in the Breast

BACKGROUND AND PURPOSE

Atypical vascular lesion (AVL) became a separate WHO diagnosis in November 2019. Due to a possible risk of developing angiosarcoma, extensive surgery with excision of AVL has been recommended but the benefit from this is questionable. We investigated whether the change in WHO classification has led to an increase in the number of patients diagnosed with AVL, thereby leading to an increase in extensive surgery.

METHOD

The Danish National Pathology Databank was used to identify patients diagnosed with AVL between June 1, 2010 to June 31, 2020. The rate of AVL diagnosed before and after change in WHO classification was compared.

RESULTS

In total, 13 cases of AVL were identified, 3 cases diagnosed before changes in WHO classification corresponding to 0.025 cases per month, compared to 8 cases, 1.143 cases per month, after the change in WHO classification. This corresponded to a 45-fold increase (95%CI: 10.88-265,31) (P < .0001) in AVL diagnosis. The mean patient age at diagnosis was 67 years. Patients received treatment varying from yearly follow up to extensive surgery. Non developed angiosarcoma in the follow-up period of 22 months.

CONCLUSION

The changes in WHO classification of AVL has led to a considerable increase in the number of patients diagnosed with the lesion. No standardized treatment exists for this rare condition, but extensive surgery is often recommended to this frail population despite the lack of evidence for prognostic benefit from the procedure. Prospective follow-up studies are needed to determine the optimal treatment strategy.

Clinical and Molecular Insights of Radiation-Induced Breast Sarcomas: Is There Hope on the Horizon for Effective Treatment of This Aggressive Disease?

Radiation-induced breast sarcomas (RIBS) are rare entities representing <1% of all primary breast malignancies, limiting most reports to small retrospective case series. They constitute a heterogeneous group of neoplasms, with high-grade angiosarcoma being the most common subtype. Other sarcoma histotypes, such as undifferentiated pleomorphic sarcoma and leiomyosarcoma, can also be identified. Radiation-induced breast angiosarcoma (RIBA) has an incidence of approximately 0.1% after breast-conserving therapy and arises mainly from the dermis of the irradiated breast. MYC gene amplification is highly indicative of secondary breast angiosarcomas. Their clinical presentation often mimics benign port-radiation lesions, leading to a delay in diagnosis and a lost window of opportunity for cure. Surgery with negative margins is the mainstay of treatment of localized RIBS. In the case of angiosarcoma, technical difficulties, including multifocality, infiltrative margins, and difficulty in assessing tumor margins, render surgical treatment quite challenging. A limited number of studies showed that adjuvant radiation therapy reduces local recurrences; therefore, it is proposed by many groups for large, high-grade tumors. Chemotherapy has been evaluated retrospectively in a small subset of patients, with some evidence supporting its use in angiosarcoma patients. Approximately half of patients with RIBA will show local recurrence. In the advanced setting, different therapeutic options are discussed in the review, including chemotherapy, antiangiogenic therapy, and immunotherapy, whereas the need for further research on molecular therapeutic targets is pointed out.

Dermatologic sequelae of breast cancer: From disease, surgery, and radiation

The care of breast cancer patients is important to dermatologists. Breast cancer's initial presentation, clinical progression, and its associated treatments can result in a variety of cutaneous complications. Dermatologists may be the first to identify a breast cancer diagnosis, as a subset of patients first present with direct extension of an underlying tumor or with a cutaneous metastasis. The surgical treatment of breast cancer also begets a variety of skin sequelae, including postoperative lymphedema, soft tissue infections, seromas, pyoderma gangrenosum, and scarring disorders. Moreover, breast cancer radiation treatment commonly results in skin changes, which can range from mild and temporary dermatoses to chronic and disfiguring skin ulceration, fibrosis, and necrosis. Radiation may also precipitate secondary malignancies, such as angiosarcoma, as well as rarer dermatologic diseases, such as radiation-induced morphea, lichen planus, and postirradiation pseudosclerodermatous panniculitis. Finally, breast cancer is also associated with an array of paraneoplastic phenomena, including Sweet's syndrome and the rarer intralymphatic histiocytosis. Herein, we review the dermatological manifestations of breast cancer, including conditions associated with its presentation, progression, and treatment sequelae. Chemotherapy-induced cutaneous side effects are beyond the scope of this review. This article provides a comprehensive review for dermatologist to be able to identify, diagnose, and manage breast cancer patients from initial presentation to treatment monitoring and subsequent follow-up.

MYC gene amplification by fluorescence in situ hybridization and MYC protein expression by immunohistochemistry in the diagnosis of cutaneous angiosarcoma: Systematic review and appropriate use criteria

BACKGROUND

Secondary angiosarcoma (AS) most commonly follows breast cancer and includes postirradiation AS (PRAS) and lymphedema-associated AS. The frequent amplification of MYC (8q24.21) in secondary AS and the rising incidence of PRAS and atypical vascular lesions (AVLs) have prompted interest in the diagnostic and prognostic utility of MYC in AS.

METHODS

Retrospective series with ≥2 cases of cutaneous AS and describing the use of fluorescence in situ hybridization (FISH) for MYC amplification or immunohistochemistry (IHC) for MYC overexpression were included.

RESULTS

Sixteen studies met inclusion criteria. Overall, 93% of cases evaluated by FISH and IHC were concordant. The sensitivity of FISH in primary AS was only 6.8%, and protein overexpression occurred without amplification in sun-damaged skin. FISH and IHC were over 78% sensitive in secondary AS but negative in over 98% of AVLs. MYC amplification and FLT4 coamplification were associated with shorter overall survival in secondary AS.

CONCLUSION

FISH for MYC amplification and IHC for MYC overexpression are useful in distinguishing PRAS from AVLs and may also have prognostic value in secondary AS. In contrast, these methods have little diagnostic or prognostic value in primary AS and should not be used to distinguish primary AS from benign vascular neoplasms.

Dermatologic toxicities associated with radiation therapy in women with breast cancer

Breast-conserving surgery with adjuvant radiation therapy has become the standard of care for women with early stage breast cancer, and as a result, a large number of patients are affected by the cutaneous sequelae of radiation therapy. These dermatologic toxicities may present during treatment or years later and can significantly impact patients’ quality of life. In this review, we discuss the clinical presentation, prevention, and management of radiation-induced cutaneous toxicities in women with breast cancer, including radiation dermatitis, radiation recall, radiation-induced morphea, radiation-induced fibrosis, and cutaneous malignancies in irradiated skin.

Atypical vascular proliferations of the neck

Atypical vascular proliferations (AVP) are a late complication after radiotherapy. Most cases have been reported in female breast cancer patients on the chest wall. These lesions are mostly of the lymphatic type. Herein, we report a blood vascular-type AVP in a male on the neck 60 years after radiotherapy for a benign hemangioma, which makes this case exceptional. We removed the whole chronic radiodermatitis surgically. Histopathology excluded vascular malignancies but confirmed AVP. We discuss the differential diagnoses and treatment.

Papillary endothelial hyperplasia (Masson's tumor) developed in the capsule of the implant in a breast cancer patient treated with mastectomy and radiation therapy

Papillary endothelial hyperplasia (PEH) is an uncommon benign vascular proliferation appearing in soft tissues in different body areas including the breast, which may be related to radiation therapy. A 48-year-old woman previously treated for breast cancer with mastectomy followed by radiation therapy and reconstruction with an implant presented with a newly developing mass in the implant capsule. Pathological diagnosis was PEH. Imaging features of this rare entity are described, and lesions included in differential diagnosis are discussed.

Vascular tumours of the breast: a comprehensive review with focus on diagnostic challenges encountered in the core biopsy setting

Vascular proliferations of the breast comprise a spectrum of benign and malignant lesions. In limited samples, such as core needle biopsies (CNB), these lesions may be difficult to distinguish due to significant overlap in morphological features. As the treatment and prognosis of these entities vary widely, it is important for pathologists to consider a complete differential diagnosis and correctly synthesise histological features, results of adjunctive immunohistochemical studies, and pertinent clinical and imaging information, to render an accurate diagnosis in such limited samples. The diagnostic pitfalls of under- or overdiagnosis of vascular lesions sampled in CNB will also be discussed.

Radiation-Associated Angiosarcoma of the Breast: Clinical and Pathologic Features

Breast angiosarcoma is an unusual malignancy accounting for approximately 1% of soft tissue sarcomas. It can occur as a primary form without a known precursor or as a secondary form associated with radiotherapy. Adjuvant radiotherapy has a significant role in preventing local recurrence in women treated with conservation therapy for early stage breast carcinoma or multicentric tumors. Postradiation angiosarcoma usually affects the dermis of the breast within the radiation field and may occasionally develop in the breast parenchyma. Compared with the latency of other radiation-associated sarcomas, the latency for breast radiation-associated angiosarcoma is relatively short with a median of 6 years. The risk of developing secondary angiosarcoma does not outweigh the benefit of treatment; therefore, radiation therapy continues to be a mainstay modality in the treatment of breast cancer patients. Early detection is essential because angiosarcomas are associated with a poor prognosis. Wide surgical resection is the standard treatment for these tumors.