{'fraction_non_alphanumeric': 0.026463963963963964, 'fraction_numerical': 0.010275900900900902, 'mean_word_length': 5.34375, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A rare etiology of a large tumoral mass of the breast - Case report primary leiomyosarcoma and osteosarcoma of the breast

Highlights • Leiomyosarcoma and osteosarcoma are exceedingly rare subtypes of breast sarcoma.• Given the exceeding rarity of breast leiomyosarcoma and osteosarcoma, consensus on ideal management of this diseases is still on debate.• We report a case of an 87-year-old female with giant breast leiomyosarcoma and osteosarcoma, treated by surgical resection and radiotherapy.• Osteosarcoma may have a rapid growth pattern with no other clinical features distinguishable to other malignant breast neoplasms.


Introduction
Breast sarcomas are a rare group of malignant tumors originating in mesenchymal breast tissue, accounting for less than 1% of all malignant neoplasms of the breast and fewer than 5% of all sarcomas. Leiomyosarcoma and osteosarcoma are exceedingly rare subtypes of breast sarcoma, the risk factors are not clarified and no specific treatment has been established yet. Macroscopically, leiomyosarcoma is a necrotic and hemorrhagic mass. We report a case of an 87-year-old female with giant leiomyosarcoma and osteosarcoma of the breast. Regarding the rarity of this entity, it is of paramount importance to identify and report these cases in order to establish the ideal therapeutic interventions, either surgical resection or radiotherapy.

Case report
An 87-year-old caucasian female, followed in Senology consultation in a community hospital, with a mass of the breast, recurred to the emergency department of the same hospital, with complaints of pain and purulent discharge of the left breast. She had no relevant medical history nor did take chronic medication.
Observation at admission revealed a volumous mass in the inferior quadrants of the left breast, ill defined, petrous consistency, with areas of necrosis and inflammatory signs. The patient had an ultrasound made 4 months earlier, where it was noted a volumous mass of polycyclic contours and surrounding oedema, with cutaneous thickening, consubstantiating a mixed pattern mass, with its multiseptated cystic component (interpretated as cystadenoma/cystadenocarcinoma) measuring 80 × 44 mm − RB = BiRADS2, LB = BiRADS4. Biopsy of the mass was taken and the result was inconclusive for malignant disease. She was then admitted to surgery ward for further study and therapy of a probable inflammatory tumor of the breast (Fig. 1). A swab sample was obtained and empiric antibiotic therapy with amoxicillin plus clavulanic acid (875 mg/125 mg 8/8 h per os) was initiated.   Breast magnetic resonance image (MRI) was obtained on the 5th day after admission, raising suspicion on possible papillary carcinoma and further raised classification to BIRADS5. Microbiological and cytological exams of the exudate were negative, and so empiric antibiotic treatment was suspended. By the 8th day of admission, an incisional biopsy of the tumoral mass was obtained, and the patient was discharged to follow-up consultation with no sign of inflammation, awaiting date of surgery, two weeks after discharge.
Histological exam of aforementioned biopsy revealed "morphological characteristics compatible with tumoral proliferation, spindle cells with elongated or irregular nuclei, non-prominent nucleolus and vacuolated cytoplasm with mitosis shape changes and foci of necrosis; scarce multinucleated giant cells and inflammatory cells". Immunohistochemical essay for antiSMA, AE1/AE3, ALK, CD31, CD34 and S100 antibodies revealed marked positivity for SMA, compatible with leiomyosarcoma.
Thoracic computerized tomography scan (CT-scan) was negative for nodes or pulmonary metastasis. Therapeutic options were discussed with the patient, who agreed with mastectomy of the left breast.
Left mastectomy was performed by a surgeon dedicated to breast surgery, and the patient was discharged with no morbidities on 5th day after surgery (Fig. 2).
Histological exam of mastectomy piece showed focal positivity for p63 and cytokeratin 5/6, within metaplastic carcinoma, with osteosarcomatous and focal leiomyosarcomatous differentiation (Fig. 3), with negative margins. Lesion was classified as pT4N0M0 and subsequent radiotherapy with a total dose of 50 Gy (2Cy/cycle/day) was performed. The patient was followed-up on Oncology and Senology consultations, for 20 months after discharge. First assessment was at 1-month post-discharge and then every 3 months for the first year and every 6 months for the second year. She remained asymptomatic, with no signs of malignancy on imaging surveillance (MRI and CT-scan) or laboratory studies.
Data was gathered through Sclinico software (in hospital and post-discharge consultation records), Operating theater and histological exam photographs. This case has been reported in line with the SCARE 2018 criteria [1].

Discussion/Conclusions
Given the exceeding rarity of breast leiomyosarcoma and osteosarcoma, there ir very little literature on this subject and consensus on ideal management is still on debate. Leiomyosarcoma frequently presents as a large tumoral mass, well delimitated, in postmenopausal women, 5th to 6th decade [2], although few tumors were as large as the one we described. Typically occurring in the uterus, retroperitoneum, subcutaneous tissues, and gastrointestinal tract [3], the breast is an uncommon primary localization [4]. Osteosarcoma may have a rapid growth pattern with no other clinical features distinguishable to other malignant breast neoplasms [2]. The characteristic histological appearance of leiomyosarcoma is that of spindle cells with elongated, pleomorphic nuclei, and definite diagnostic obtained through immunohistochemical exam reactive to desmin, vimentin and SMA and negative for cytokeratin, myoglobin and S100 [2]. Most authors establish complete surgical excision of tumoral mass with free margins as standard treatment for breast sarcomas. On this case, our experience is that a female patient with a volumous leiomyosarcoma and osteosarcoma of the breast, without relevant medical history, treated in a community hospital by surgical resection with mastectomy and adjuvant treatment with radiotherapy (total dose of 50 Gy), similarly to the treatment of other sarcomas of the breast, had very good results, with no signs of malignancy or morbidity at 20 months after surgery. Despite our experience, more research is needed regarding leiomyosarcoma and osteosarcoma of the breast to better understand them, including risk factors and behavior of this malignancy, and define the best way of treatment.

Declaration of Competing Interest
None.

Funding
None.

Ethical approval
The informed consent used was previously approved by the local Ethics Committee (Centro Hospitalar do Médio Tejo, E.PE -Tomar, Portugal).
The local Ethics Committee exempt case reports of an individual approval.

Consent
Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.