Metástasis de Sarcoma en el Esternón

Metastasis of Soft Tissue Sarcoma in the Sternum

Metastasis of Sarcoma in the Sternum. Patient with pain and tumor on the medial aspect of the right thigh, affecting the soft tissues. The best imaging test to evaluate soft tissue injuries is magnetic resonance imaging (MRI). This examination revealed the presence of a solid lesion measuring approximately 5.5 cm by 7.0 cm, within the adductor muscles of the thigh (Figures 5, 6, 7, and 8).

 
Figura 6: RM ax T1 com saturação de gordura, evidencia o vaso nutrício da lesão
Figure 5: MRI ax T1, with low signal, heterogeneous lesion, close to the plane of the adductor muscles of the thigh. Figure 6: MRI ax T1 with fat saturation, showing the nutrient vessel of the lesion
Figura 7: Rm sag com captação de contraste e evidente vascularização.
Figure 7: MRI sag with contrast uptake and evident vascularization.
Figura 8: Rm ax, captação de contraste, heterogênea, vascularizada e com aparente delimitação por pseudocápsula.
Figure 8: MRI ax, contrast uptake, heterogeneous, vascularized and with apparent delimitation by a pseudocapsule.

With this clinical and imaging picture we have to answer the following question:

1- Perform a biopsy, or biopsy resection, since in this case it is possible to excise the lesion with an oncological margin, without changing its function? 

2- If the biopsy result reports a lesion without atypia, fibroxanthoma for example, would surgical resection change? Would a resection be more economical? Even with the characteristics of these images, since the biopsy is only a small sample of the lesion?

For us, conduct cannot change . Resection must be performed with an oncological margin in this case. The biopsy is performed with the aim of guiding neoadjuvant therapy if it is confirmed to be a sarcoma. 

3- What type of biopsy to perform? With Tru-cut needle? Incisional? With diagnosis by freezing and management?

It is best to always perform a biopsy of soft tissue lesions with a tru-cut needle, guided by ultrasound and frozen pathological anatomy, to validate the material collected. The resection procedure will depend on each case and can be performed in cases where the oncological margin is possible, without functional loss. Otherwise, you must wait for the final result of the anatomical pathological examination, including immunohistochemistry, when necessary.

In this case, the diagnosis was  high-grade sarcoma , on frozen section and as resection with a margin was possible, the surgery was performed under the same anesthesia (Figures 9 and 10). We can observe the histological aspect of this tumor (Figures 11, 12 and 13).

Figura 10: Peça ressecada com margem ampla.
Figure 9: Resection of high-grade sarcoma on the medial aspect of the thigh, with a wide margin. Figure 10: Resected piece with wide margin.
Figura 12: Grande desarranjo celular.
Figure 11: Polymorphic cells, with hyperchromasia and cellular atypia. Figure 12: Major cellular disarray.
Figura 13: Anaplasia, caracterizando sarcoma indiferenciado de alto grau.
Figure 13: Anaplasia, characterizing high-grade undifferentiated sarcoma.

Adjuvant radiotherapy was initiated during surgery with the placement of catheters for brachytherapy. These catheters are passed through a needle with sufficient tubular diameter. The catheters are passed and secured with a plastic clip (Figures 14 and 15). The catheters are subsequently removed and completed with external radiotherapy. Figure 16 shows the local appearance after treatment.  

Figura 15: Pele suturada e cateteres posicinados paralelamente, distantes 1,5 cm entre si e fixados por presilha plástica.
Figure 14: Catheters for brachytherapy, positioned in the operating bed where the tumor tissue was located. Figure 15: Sutured skin and catheters positioned in parallel, 1.5 cm apart and fixed with a plastic clip.
Figura 16: Aspecto da cicatrização da ferida operatória, após a cirurgia e o tratamento radioterápico adjuvante.
Figure 16: Appearance of surgical wound healing after surgery and adjuvant radiotherapy treatment.

The case was discussed in a multidisciplinary team that chose not to perform adjuvant chemotherapy, as the relationship between possible benefits and side effects was not favorable, taking into account the fact that it does not increase overall survival, Lancet 1997 1 .

In the control evaluation, after four years and three months, the patient reported bulging and pain in the sternum. The lateral x-ray highlights the presence of a lesion in the distal portion of the sternum (Figures 17 and 18). The bone scintigraphy performed for skeletal staging revealed a single lesion, with intense uptake in this region (Figures 19 and 20).

Figura 17: Radiografia do tórax PA.
Figure 17: PA chest x-ray.
Figura 18: Radiografia de tórax, em perfil, evidencia lesão expansiva no esterno.
Figure 18: Chest X-ray, in profile, shows an expansive lesion in the sternum.
Figura 19: A cintilografia apresenta intensa captação na metade inferior do Esteno.
Figure 19: The scintigraphy shows intense uptake in the lower half of the Stenus.
Figura 20: Em destaque, a captação no esterno.
Figure 20: Highlighted, the capture in the sternum.
Figura 21: Tomografia de tórax
Figure 21: Chest tomography
Figura 23: Tomografia de abdome
Figure 23: Abdominal tomography
Figura 22: Tomografia de toráx, evidenciando o comprometimento do esterno, densidade para tecidos moles
Figure 22: Chest tomography, showing involvement of the sternum, density for soft tissues
Figura 24: Tomografia de toráx, evidenciando o comprometimento do esterno, densidade para tecido ósseo.
Figure 24: Chest tomography, showing involvement of the sternum, density for bone tissue.
Figura 25: Ressonância magnética coronal T1
Figure 25: Coronal T1 MRI
Figura 26: Ressonância magnética coronal T1
Figure 26: Coronal T1 MRI
Figura 27: Ressonância magnética sagital T1, evidenciando a erosão e abaulamento da região.
Figure 27: T1 sagittal magnetic resonance imaging, showing erosion and bulging of the region.
Figura 28: Ressonância magnética sagital T1 com contraste mostrando uma lesão heterogênia de alto e baixo sinal.
Figure 28: Sagittal T1 MRI with contrast showing a heterogeneous lesion of high and low signal.

With this patient’s clinical history and these images, we asked the following question:

1- Would you take a biopsy of this lesion? 

2- What should we do if we are diagnosed with benign fibrohistiocytoma? or aneurysmal bone cyst? What is the conduct? Curettage? With this patient’s history of high-grade sarcoma? The biopsy is just a sample, so it is questionable to repeat the biopsy until a diagnosis of a malignant lesion is made in this patient. We must assume the need for resection with margin of this lesion, since it is the oncological approach and resection of the sternum does not cause aesthetic or functional damage. Neoadjuvant chemotherapy would not add any advantages to the case, nor would prior radiotherapy change the need for resection of the affected area. 

3- If we are going to resect the sternum, what access route should we use? What is the incision that allows wide and more aesthetic resection?

We chose the horizontal, inframammary route (Figures 29, 30, 31, 32 and 33).

Figura 29: Incisão realizada na região infra mamária
Figure 29: Incision made in the infra-mammary region
Figura 30: Ressecção do esterno.
Figure 30: Resection of the sternum.
Figura 31: Imagem do local onde foi ressecado o esterno.
Figure 31: Image of the place where the sternum was resected.
Figura 32: Uma visualização da peça ressecada.
Figure 32: A view of the resected piece.
Figura 33: Radiografia da peça evidenciando o lesão.
Figure 33: Radiograph of the piece showing the injury.
We can observe the good hemostasis achieved, which must be careful to eliminate the need for drain placement and allow for better aesthetics.
4- How to reconstruct this cavity? In this case, there is no need for a sternum prosthesis or the placement of a rigid cement plate. There is no flaccid chest. We close the surgical wound with a marlex mesh, which is flexible and allows the formation of scarring fibrosis, plugging the cavity.
Figura 34: Reconstrução da cavidade com Tela de Marlex.
Figure 34: Reconstruction of the cavity with Marlex Mesh.
In this second video, we observe normal respiratory function, one week after surgery.
The aesthetic appearance three years and five months after the operation (Figure 35).
Figura 35: Reconstrução da cavidade com Tela de Marlex.
Figure 35: Reconstruction of the cavity with Marlex Mesh.

This case was discussed again in a multidisciplinary meeting. Postoperative radiotherapy was not indicated after the type of en bloc resection in this case, in this location. The literature review at the time did not indicate the benefit of chemotherapy versus toxicity and the evidence of overall survival was equal, Cancer 2008 2 . The patient does not receive adjuvant treatment.

After seven years and eight months of treatment for the thigh tumor and four years and two months of resection of the sten, the patient presented metastasis in the right calf (Figures 36 and 37) and the staging revealed a lesion in the thoracic vertebra, T11 and in the retroperitoneum (Figures 38 and 39). 

Figura 36: Uma visualização em perfil da panturrilha direita.Figura 37: Lesão metastática na panturilha.
Figure 36: A lateral view of the right calf. Figure 37: Metastatic lesion in the calf.
Figura 38: Imagem evidenciando a lesão na vértebra Toráxica T11. Figura 39: Visualização mais próxima da lesão na vértebra toráxica T11 e no retroperitoneo.
Figure 38: Image showing the injury to the T11 Thoracic vertebra. Figure 39: Closer view of the lesion in the T11 thoracic vertebra and in the retroperitoneum.
Figura 40: Ressonância magnética axial em T1
Figure 40: Axial T1 magnetic resonance imaging
Figura 41: Ressonância magnética axial em T2 com contraste.
Figure 41: Axial T2 magnetic resonance imaging with contrast.
Figura 42: Ressonância magnética axial em T1, corte mais distal.
Figure 42: Axial magnetic resonance imaging in T1, most distal section.
Figura 43: Ressonância magnética axial em T2.
Figure 43: Axial T2 magnetic resonance imaging.
Figura 44: Ressonância magnética em T1 do tumor. Figura 45: Peça ressecada em 1999. Figura 46: Ressonância magnética sagital em T1.
Figure 44: T1 MRI of the tumor. Figure 45: Specimen resected in 1999. Figure 46: T1 sagittal magnetic resonance imaging.
Figura 47: Peça ressecada em 2004. Figura 44: Rm axial T1 do tumor do esterno e a peça ressecada, em 2004.
Figure 47: Piece resected in 2004. Figure 44: Axial T1 MRI of the sternum tumor and the piece resected in 2004.
Figura 48: Pet-Cet, lesão metastática na vertebra T11, em 2007.
Figure 48: Pet-Cet, metastatic lesion in the T11 vertebra, in 2007.
Figura 49: Perna com aumento de volume na panturrilha; pet-cet com alta captação na lesão; Rm em T1 e T1 com contraste pré e pós quimioterapia, em 2008
Figure 49: Leg with increased volume in the calf; pet-cet with high uptake in the lesion; T1 and T1 MRI with contrast before and after chemotherapy, in 2008
Figura 50: Tomografia do tórax, múltiplas metástases nos ápices pulmonares.
Figure 50: Chest tomography, multiple metastases in the lung apices.
Figura 51: Tomografia de tórax, com ínúmeras metástases, em ambos os pulmões, em 2011.
Figure 51: Chest tomography, with numerous metastases, in both lungs, in 2011.

A randomized study in 2012 of adjuvant chemotherapy with doxorubicin and ifosfamide did not show any benefit in relapse-free survival or overall survival, Lancet 3 . In the literature in 2013, the benefits of neo-adjuvant and adjuvant chemotherapy, UpToDate 4, are still uncertain . 

Chemotherapy for soft tissue sarcoma still needs to evolve a lot. The vast majority of treatments for these sarcomas are not individualized. We know that chemotherapy for Ewing sarcoma is different from chemotherapy for osteosarcoma, which is why we have favorable results in the treatment of these conditions. The large pool  of sarcomas cannot be placed  on the same treatment protocol. Just as work on the outcome of treatment of this  pool  of tumors does not allow conclusions. Cases that respond are mixed with the majority that do not respond and the chemotherapist is left without parameters. In adults, toxicity is worsened by comorbidities and the cost/benefit ratio is unfavorable. 

Surgery is still the primary treatment for soft tissue sarcomas. Radiotherapy has its role in controlling high-grade sarcomas, but it does not rescue an inadequate resection. Neoadjuvant radiotherapy has fewer complications for the surgical wound than brachytherapy. Adjuvant radiotherapy is recommended in practically all cases, with the exception of superficial lesions, resectable tumors smaller than five centimeters and lesions of low histological grade, UptoDate 5 .

Bibliographic references

1.Adjuvant chemotherapy for localized resectable soft tissue sarcoma of adults: meta analysis of individual data, Lancet 1997; 350:1647-54

2.Adjuvant and neoadjuvant chemotherapy

3.Local treatment for primary soft tissue sarcoma of the extremities and chest wall

4.Treating soft tissue sarcomas

Author: Prof. Dr. Pedro Péricles Ribeiro Baptista

 Orthopedic Oncosurgery at the Dr. Arnaldo Vieira de Carvalho Cancer Institute

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