Introduction

Ewing´s family tumors (EFT), include Ewing Sarcoma (ES) and it´s form extraosseous (EES) and includes Primitive Neuroectodermal Tumor (PNET) and represent about the 5-10% of the primary bone tumors, extra skeletal PNET form it is a rare presentation, and the breast are described only in case reports; there is not information about the best treatment in this cases, but surgery of early stage represents the most used management, and the chemotherapy on the advanced cases with Vincristine/Adriamycin/Cyclophosphamide (VAC), the multidisciplinary model to treat this cases results indispensable to increase the overall survival (OS).

Case report

A 49-year-old female with a progressively enlarging breast nodule of 6 months of evolution, she had no significant past medical or family history. Initially, she was on alternative medicine for 4 months without improvement. The initial mammography reported Breast Imaging Reporting and Data System-3. Physical examination revealed a hyperemic 10 × 9 cm mass, occupying all quadrants of the right breast; ipsilateral axillary adenopathy was palpable (Fig. 1).

Figure 1 The tumor occupied completely the rigth breast and with some scab areas. 

A positron emission tomography – computed tomography (Fig. 2) scan reveals a multilobulated and septated right breast mass with nipple-areola complex infiltration, axillary, and internal mammary lymph node chain infiltration. Metastases were detected in multiple intra-axial lesions of the brain, infraspinatus muscle, bilateral lung nodules, supradiaphragmatic implant, left malignant pleural effusion, mediastinal disease, parenquimal implant in left kidney, intramural uterine lesion and bone deposits on proximal right femur, ipsilateral iliac, and spinal column (T1, T3, L1).

Figure 2 (18F-FDG) PET/CT scanner showing bulky disease in the right breast, locoregional nodes and metastatic disease. 

An incisional biopsy of the right breast was performed with a pathological report of a neuroectodermal primitive tumor (primitive neuroectodermal tumor [PNET) with positive immunohistochemistry for Vimentin, CD99, TLE-1, CD56, and CK AE1/AE3 (Fig. 3).

Figure 3 Immunohistochemistry for CK AE1/AE3, Vimentin, CD56 and CD99. 

A tunneled pleural catheter was placed on the left chest; due to intense neuropathic pain in T4-T8 left regions, an erector spinae plane block was made.

Whole-brain radiotherapy was administered, 30 Gy on 10 fractions. At the end of the WBR, vincristine, adriamycin, cyclophosphamide (VAC) chemotherapy was administered for one cycle. She complicated with hemodynamic deterioration by septic shock, respiratory failure leading to cardiac arrest, and die.

Discussion

PNET tumors belong to the spectrum of Ewing’s family tumors (EFT), having similar histologic characteristics with small round cell morphology but a different neuroectodermal differentiation. The definitive diagnosis includes histology sample, immunohistochemistry, molecular pathology, and biobanking; CD99 is a relevant diagnostic marker, is evident by immunohistochemistry in about 95% of Ewing’s sarcoma; however, CD99 expression is not specific, immunohistochemical detection of FLI1 is more specific for Ewing’s sarcoma than CD99; however, the specificity of FLI1 is limited by its expression in other hematologic diseases and soft-tissue sarcomas¹,².

In 85% of the cases is associated with translocation t(11;22)(q24;q12), this fusion of EWS gene on 22q12 with the FLI1 gene on 11q24 results in a chimeric fusion transcript EWS-FLI1, there are others in less frequency like the translocation t(21;12)(22;12) in about 10-15%³.

The skeletal variant represents about 5-10% of bone tumors, and the peripheral presentation is more uncommon³,⁴, has been described in different organs being the breast a very rare primary site; the information is limited and the prognostic can be established by extraskeletal EFT with overall survival (OS) at 5 years of 38%⁵.

Breast PNET is only in the literature by case reports; there are only a few previous cases (Table 1) and only three with metastatic disease and different prognostic.

The treatment involves a multidisciplinary approach between chemotherapy and local therapy (surgery, radiation therapy, or both) to maximize the chance of cure and minimize the risk of long-term sequelae. However, although OS for patients with the localized disease now approaches 65-75%, efforts should be pursued to better tailor therapy and especially to improve the outcome for patients with metastatic and recurrent where the OS is < 30%¹⁶.

Therefore, we translate the information of the articles in bone and soft tissue diseases, so we use the VAC scheme as an initial treatment for our patients.

We do not have evidence of the benefit of adding etoposide and ifosfamide in the metastatic context is useful¹⁷, in addition to the series of cases already mentioned (Table 1) where the most used scheme was VAC.

Conclusion

PNET tumors are a rare disease and the presentation as a primary site in the breast, even more, there is no standard treatment for this pathology, and the scheme of chemotherapy results controversial using VAC in the most cases; however, the prognosis is poor in the metastatic and recurrent setting, leading to the individualization of the case for multidisciplinary treatment.