Two cases of sternectomy for bone metastasis due to aggressive variants of thyroid papillary carcinoma

Abstract

INTRODUCTION

There are only few cases reported about the role of surgery in the presence of single or multiple bulky bone metastases. The literature about treatment for bulky sternal metastases is scarce.

PRESENTATION OF CASE

We present two patients treated surgically for metastatic thyroid lesions. Case 1 is a female with tumor of the thyroid right lobe, mediastinal extension and multiple pulmonary metastases. Bony infiltration was observed in the sternum and ribs. Case 2 is a female with a lesion in the cervical region of the thyroid left lobe and increase in volume on the upper sternal manubrium.

DISCUSSION

Patients with well-differentiated thyroid cancer may present with extracervical metastasis in 5–10% of cases at diagnosis. Bone metastases occur in 0.4% of cases of papillary carcinoma. Management remains controversial. There are only isolated cases reported in the literature of the role surgery plays in the presence of single or multiple bulky bone metastases. The basis for initial surgical approach is keeping in mind that the surgical procedure is palliative in order to achieve optimal hypothetical ablation as a result of reduced tumor volume.

CONCLUSION

Surgery is the elective treatment and can be performed safely and with adequate results, allowing proper optimization of the dose of ¹³¹I for ablative therapy.

1. Introduction

Thyroid cancer is the most common tumor of the endocrine system and has the most rapid annual increment (4%) of all tumors. The prognosis of patients with differentiated thyroid cancer is excellent and 10-year survival is >90%.¹ However, survival is lower with poorly differentiated tumors, even in those tumors considered as intermediate such as insular tumors, which in Mexico, represent 4.5–7%.² Dissemination of thyroid cancer is primarily via regional lymph nodes and metastatic pulmonary disease may develop, followed by bone involvement.³ Only isolated cases have been reported in the literature describing surgical treatment in bulky sternal metastases. Management remains controversial; therefore, we report our experience with two patients.

2. Case 1

A Mexican 30-year-old female who presented in August 2010 with progressively growing tumor in the anterior neck, associated with occasional dyspnea and dysphagia. Initial physical examination revealed a tumor dependent of the right lobe of the thyroid gland (5 × 4 cm), which was soft, adherent to deep planes and without palpable lymph nodes. In the upper sternal region, there was a soft, fixed tumor (∼4 cm). Initial computed tomography (CT) scan demonstrated a tumor of the right lobe of the thyroid gland (6 × 4 cm) with mediastinal extension and multiple bilateral lung metastases. Bone infiltration was also observed in the right sternum and ribs^5–7 as well as a solid lesion below the middle third of the left kidney (∼28 mm in diameter), which was initially considered to be metastatic. Fine needle aspiration biopsy of the sternal lesion was performed, with histopathologic report of follicular neoplasm. During a first surgical intervention, the patient underwent total thyroidectomy, partial sternectomy, and partial resection of the fifth, sixth and seventh right ribs. Eight days later, the patient underwent left partial nephrectomy. She was discharged 4 days later with a satisfactory evolution. Pathological study for the thyroid tumor reported poorly differentiated, insular-type carcinoma (80%) associated with conventional papillary carcinoma lined with tall cells (20%), located in the lower pole of the right lobe. There was vascular and lymphatic permeation and extension to perithyroid soft tissues. Sternal lesion was compatible with poorly differentiated, insular-type papillary carcinoma with soft tissue invasion and lymphatic permeation. Bony margins were free of neoplasm. The ribs were also found to have metastatic disease. However, the lesion found in the left kidney corresponded to a classic angiomyolipoma, which was completely resected. The patient underwent ¹³¹I ablation therapy at a dose of 150 mCi due to the conventional papillary component. Appropriate incorporation of the radiopharmaceutical was found in the thyroid bed and in the diseased lung. At the 6-month follow-up, the patient demonstrated parathyroid hormone levels in the normal range and TSH suppression with 150 mg of levothyroxine (Figs. 1 and 2).

Fig. 1.

A 30 years old female patient where CT demonstrates the following: (A) Sternal metastasis. (B) Seventh to ninth rib metastasis on the right side. (C) Peripheral lesion of the left kidney suspicious of visceral metastasis due to thyroid carcinoma. (D) Total thyroidectomy and sternal en bloc resection. (E) Seventh to ninth rib metastasis en bloc resection.

Fig. 2.

(A) 74 year old female patient with clinical evidence of sternal metastasis. (B) Sternal en bloc resection with a rim resection of the clavicle. (C) Reconstruction defect after sternal resection with polypropylene mesh. (D) Clinical results after primary closure.

3. Case 2

A Mexican 74-year-old female who in March 2011 arrived at our institution due a 3-year evolution of increased volume in the upper sternal region associated with pain. Upon initial physical examination, a lesion was found in the cervical region of the left lobe of the thyroid (∼4 × 4 cm), along with an increase in volume on the upper sternal manubrium (5 × 5 cm). Lymph nodes were palpated bilaterally. During the initial evaluation, an ultrasound was carried out and reported a thyroid lesion predominantly altering the left morphology. A rounded hypoechoic image was identified in the right lobe with calcified edges measuring 19 × 9 mm. The lesion was heterogeneous with ill-defined borders and reached the superior mediastinum. Multiple bilateral lymphadenopathy of indeterminate aspect at the right IIA cervical level measured 16 × 4 mm and at the left III cervical level measured 17 × 6 mm. Bone scan was performed with report of metastatic bone pathology of the first right rib and sternal manubrium. The patient underwent surgery, which involved total thyroidectomy, bilateral modified radical neck dissection, partial sternectomy, partial resection of the first right rib, Marlex mesh reconstruction and placement of bilateral Slidex Pneumokit (bioMérieux). The patient was discharged 4 days postoperatively without complications. Final pathology report was conventional-type papillary thyroid carcinoma with solid areas, oxyphilic changes and squamous metaplasia with lymphovascular permeation and invasion to adipose tissue and striated muscle. Sternal resection demonstrated bone tissue with metastases from papillary thyroid carcinoma with invasion to soft tissue and negative margins. Metastatic disease was found in 3/60 nodes during neck dissection. Due to these findings, after administration of Thyrogen (Genzyme) (thyrotropin alpha) at a dose of 0.9 mg IM on two consecutive days, the patient underwent ablation with ¹³¹I (total of 150 mCi). Radiopharmaceutical tracer was demonstrated in the thyroid bed. Currently the patient is under suppression with levothyroxine at a dose of 150 μg per day and is asymptomatic.

4. Discussion

According to the series reviewed, patients with well-differentiated thyroid cancer may present with extracervical metastasis in 5–10% of cases at diagnosis.⁴ Do et al.⁵ reported an incidence of bone metastases of 0.4% (13/3154) due to papillary carcinoma. Management remains controversial. An increased frequency of lung and bone disease has been reported in follicular variants because dissemination is predominantly hematogenous, which is less frequent in the papillary variant. Insular tumors of the thyroid may present with clinical and pathological features similar to papillary carcinoma, e.g., a tendency to spread via the lymphatic system, extrathyroidal invasion, lung metastases, and other features of follicular carcinoma such as bone metastases and visceral involvement.⁶

There are only isolated cases reported in the literature of the role surgery plays in the presence of single or multiple bulky bone metastases (Table 1). The basis for initial surgical approach is keeping in mind that the surgical procedure is palliative in order to achieve optimal hypothetical ablation as a result of reduced tumor volume. As reported in Case 1, the patient had disease in the lung, sternum and ribs and resection was performed of the renal lesion which, at that time, was considered to be a metastasis and ultimately was diagnosed as a primary tumor of the kidney.

Table 1.

Patient information for reported cases of sternal thyroid cancer metastases.

Case No.	Age (yr)	Sex	Size (cm)	Diagnosis	Symptoms	Other metastases	Year reported	References
1	61	F	6 × 5 × 4.5	Follicular	Pain	None	2006	Eroglu et al.
2	35	F	7 × 7	Poorly differentiated/follicular component	Pain	None	2000	Mishra et al.
3	43	M	7 × 10	Follicular	None	Pulmonary/vertebral	2000	Mishra et al.
4	69	F	8 × 4.5	Papillary	Pain	None	2004	Haraguchi et al.
5	54	F	4 × 4	Follicular	Pain	Pulmonary	1995	Ozaki et al.
6	48	F	8 × 6	Papillary	Pain	None	1995	Ozaki et al.
7	59	F	NR	Follicular	NR	Left neck	2005	Meyer et al.
8	62	F	NR	Poorly differentiated with follicular component	NR	Three lymph nodes	2001	Kinoglou et al.
9	75	F	12 × 9	Follicular	None	None	1998	Muthuphei et al.
10	75	F	14 × 8 × 7	Poorly differentiated with follicular component	Pain	Pulmonary	2008	Yanagawa et al.
11	35	F	4.5 × 4.5 × 3	Poorly differentiated (insular) with papillary component	Dysphagia Dyspnea	Ribs Lungs	2011	Present case
12	74	F	8 × 5.1 × 4.5	Papillary	Pain	Three lymph nodes	2011	Present case

NR, not reported.

Modified from Yanagawa et al. J Thorac Oncol. 2009;4:1022–5.

During the 1990s, Ozaki et al.⁷ reported the ability to resect metastatic lesions to the sternum in two patients with well-differentiated thyroid cancer with a good evolution. Special attention was paid to sternal reconstruction using acrylic resin and a polypropylene mesh. We now believe that this procedure is obsolete because reconstruction with polypropylene mesh is sufficient. As shown in our cases and in cases where it is necessary to include part of the skin, there is an option of reconstruction with free flaps after placement of the mesh and an anastomosis to the internal mammary artery⁸ (Table 2).

Table 2.

Treatment information for reported cases of sternal thyroid cancer metastases.

Case No.	Resection	Reconstruction	Margins	Complications	Follow-up	Recurrence	Additional treatment
1	Partial sternectomy, including manubrium and attached portions of bilateral clavicles and costal cartilage	Gore-Tex soft-tissue patch, bipedicled pectoralis major flaps	NR	None	1 yr	No	RAI
2	Partial sternectomy, medial 2 cm of clavicles, first and second ribs	Marlex mesh	NR	None	None	Unknown	None
3	Partial sternectomy, anterior first 3 ribs, medial clavicles, manubrium	Marlex mesh	NR	None	NR	No	RAI, resection of vertebral metastasis
4	Subtotal sternectomy	Marlex mesh sandwiched between stainless steel mesh	NR	None	3 mo	No	None
5	Total sternectomy	Artificial sternum made of methyl methacrylate secured with metallic wires	NR	None	2.5 yr (death)	Yes (pulmonary and bony metastases)	RAI
6	Subtotal sternectomy	Methyl methacrylate sandwiched between Marlex mesh	NR	None	5mo	No	None
7	Partial sternectomy	Polypropylene mesh	NR	None	4.5 yr	Yes (pulmonary metastases, local recurrence in the neck)	RAI × 4
8	Partial sternectomy	Marlex mesh, left pedicled pectoralis major muscle flap	Negative	None	1 yr	No	External radiation
9	NR	Prolene mesh	NR	Bleeding, sepsis	1 mo	No	None
10	Total sternectomy	Methyl methacrylate sandwiched between layers of polypropylene mesh, bipedicled pectoralis major muscle flaps	Negative	None	2 yr	Yes (unknown location)	RAI × 2
11	Partial sternectomy, resection of 3 ribs	Marlex mesh	Negative	None	7 mo	No	RAI
12	Partial sternectomy, resection of 2 ribs	Marlex mesh	Negative	None	2 mo	No	RAI

Partial sternectomy, <50% resection; subtotal sternectomy, >50% resection; total sternectomy, 100% resection. NR, not reported; RAI, radioiodine.

Modified from Yanagawa et al. J Thorac Oncol. 2009;4:1022–5.

In a study by Pak et al.⁹ that reported the experience of resection of metastatic lesions in non-medullary thyroid cancer, there were 14 patients reported with bone disease from a total of 47 surgeries performed. Although sternal disease was not reported, it was concluded that patients may have a discrete improvement in disease-free period or at least greater effectiveness toward the administration of iodine after metastasectomy. This is especially true when an adequate resection of bone lesions has been done in the presence of lung metastases and where the use of ¹³¹I is optimized for treatment of these pulmonary lesions where surgery has a limited role, as reported here for Case 1.

Yanagawa et al.¹⁰, in a review of 10 patients presenting with metastatic disease to the sternum, reported that all patients were candidates for safe surgical resection and with adequate palliation, as well as for the hypothetical potentiation of iodine therapy. In addition to the above, it prevented symptoms associated with these lesions such as pain, ulceration, and dyspnea, which occur at later stages in these patients and affect their quality of life, as reported by Kitamura et al.¹¹ These authors observed that patients with sternal disease may present superior vena cava syndrome, with consequent circulatory arrest and immediate death. We observed that, despite the poor prognosis of patients with metastatic bone and multiple lung disease, surgery can be performed safely and with adequate results in younger or older patients, as in our cases reported here.

In conclusion, sternal metastases and resection surgery, when possible, allow for optimization of the dose of ¹³¹I. In the presence of lung metastases, there is an important palliative role from the standpoint of pain, which allows the patient to have a near-normal quality of life because, after sternal resection, quality of life is not altered.

Conflict of interest statement

None.

Funding

None.

Ethical approval

None.

Author contributions

Kuauhyama Luna-Ortiz – study design, write manuscript; Rosa A Salcedo Hernández – write manuscript; Leonardo Saul Lino-Silva – review and write manuscript; Antonio Gómez-Pedraza – review and write manuscript.