Rhabdomyosarcoma of the breast: Report of two cases with the review of literature

Embryonal rhabdomyosarcoma of breast, pleura, and retroperitoneum diagnosed from pleural fluid cytology

Embryonal rhabdomyosarcoma (ERMS) is a malignant small blue round cell tumor which is commonly seen in head and neck region. Breast and pleural involvement are uncommon. Rhabdomyosarcoma has been rarely reported in the body fluids like ascitic, pleural, and cerebrospinal fluid. In this article, we report an interesting case of ERMS which had deceptive small blue round cells in pleural fluid. The cytomorphological features along with a panel of immunocytochemical markers helped in arriving at the definite diagnosis. Later, biopsy from the breast lump and retroperitoneal mass also revealed the same tumor. This case is reported since it is rare to find sarcoma cells in pleural fluid and highlight the diagnostic difficulties faced during interpretation.

Isolated Breast Relapse after Metastatic Alveolar Rhabdomyosarcoma in a Young Premenarcheal Girl: What Could Have Been Done?

Alveolar rhabdomyosarcoma (RMS) is one of the most common pediatric soft-tissue neoplasms. Breast involvement either as primary tumor or metastasis is extremely rare. Herein, we report a case of primary limb alveolar RMS with breast metastases in a young premenarcheal girl that relapsed only to the metastatic breast site after achieving complete response. Accordingly, we believe that investigations of the mammary glands should be part of the routine diagnostic workup in adolescent females with RMS. Local therapeutic measures to control breast disease, including surgery or radiotherapy has to be considered for better prognosis. Newer radiation modalities aiming at reducing side effects should be developed.

Primary Rhabdomyosarcoma of the Breast: Study of Three Cases at One Institution with a Review of Primary Breast Sarcomas

BACKGROUND

Primary breast sarcoma (PBS) is rare, comprising approximately 1% of breast malignancies. Rhabdomyosarcoma (RMS) accounts for an extremely small proportion of PBSs, often leading to delayed histologic confirmation.

METHODS

Upon reviewing Asan Medical Center's pathology database between 2000 and 2018, 41 PBS cases were retrieved, including three cases of primary RMS of the breast. Their clinicopathological features were analyzed, and the literature related to PBS and primary RMS of the breast was reviewed.

RESULTS

We identified three primary breast RMS cases from our institution database, comprising 7.3% of PBS: one case each of spindle cell/sclerosing RMS (ssRMS), alveolar RMS (aRMS), and embryonal RMS (eRMS). All cases involved adolescents or young adults (14, 16, and 25 years, respectively) who underwent mastectomy or radiotherapy and were confirmed using immunohistochemical testing for myogenin, desmin, and myogenic differentiation. The ssRMS patient experienced recurrence at the operation site 4 months post-surgery despite undergoing concurrent chemoradiotherapy. The aRMS patient had multiple metastases at diagnosis and showed FAX3-FOXO1 fusion transcripts; she died 22 months after the diagnosis. The eRMS patient had enlarged axillary lymph nodes; post-radiotherapy, the lesion recurred as multiple metastases to the bone and lung. She died 18 months post-diagnosis.

CONCLUSIONS

Our experience on RMS cases suggests that spindle cell or small round cell malignancy in breasts of young female should raise suspicion for the possibility of primary or secondary RMS. To our knowledge, this is the second report of primary breast ssRMS and it may help clinicians who encounter this rare disease in the future.

Primary Rhabdomyosarcoma of the Breast: Imaging Findings and Literature Review

Background

Primary breast rhabdomyosarcoma (RMS) can occur in children. There is a lack of knowledge regarding radiologic findings and added diffusion-weighted magnetic resonance imaging (MRI) features of RMS in the literature.

Case Report

A 12-year-old girl was diagnosed with primary alveolar RMS of the breast. Gray scale ultrasound revealed posterior acoustic enhancement behind a well-circumscribed, multilobulated hypoechoic mass. Doppler ultrasound revealed increased peripheral and central vascularity. Hypointense septations on T2-weighted image exhibiting more enhancement than the stroma on late gadolinium-enhanced images were striking within a hyperintense mass. A hyperintense hemorrhagic focus on T1-weighted image was present in the absence of any necrosis. Avid enhancement on early postcontrast images proceeding from the periphery to the center was depicted.

Conclusion

A rapidly enlarging mass with an echogenic peripheral rim together with posterior acoustic enhancement on gray scale ultrasound, intense vascularity on Doppler ultrasound, axillary lymphadenopathy, and satellite nodules on MRI should raise suspicion. Enhancing central and peripheral septations are suggestive of RMS. Dynamic contrast-enhanced MRI in suspected cases can provide valuable data in the differential diagnosis.

Rhabdomyosarcoma Revealed by a Breast Metastasis

A 38-year-old woman was referred for staging of an alveolar rhabdomyosarcoma revealed by a breast metastasis with unknown primary. Whole-body F-FDG PET/CT localized the primary tumor as an asymptomatic soft tissue lesion of the right foot with a significant uptake. PET/CT detected hepatic and pancreatic metastases and also showed a multifocal bone marrow involvement, which was not detected by the contrast-enhanced CT. These results led to a significant change in treatment management as the patient received local radiotherapy of the primitive lesion and polychemotherapy.