Chondroma of the Sternum Growing in a Pregnant Patient: A Case Report

Abstract

Purpose: Benign tumors are known to grow or develop sometimes during pregnancy. We present a case report about a young woman with a growing sternal tumor.

Methods: After her second pregnancy, a 32-year-old female presented with a rapid growing sternal tumor. Computed tomography (CT) scan revealed a tumor measuring 10 × 8 × 7 cm with an intrathoracic bulk, compressing the heart and the upper margin of the liver.

Results: Resection of the tumor was performed uneventfully. Histologic examination of the resected mass revealed a chondroma.

Conclusion: To the best of our knowledge, this is the first report of a huge sternal chondroma growing in a pregnant patient. There is not often a need to treat these patients before delivery, however, thereafter surgical treatment of growing tumors is recommended.

Introduction

Tumors appear in one out of every 1000 pregnancies. The most frequently observed malignancy occurring during pregnancy is breast cancer.¹⁾ Benign tumors are known to grow or develop sometimes during pregnancy (e.g., meningiomas²⁾). To the best of the authors’ knowledge, there are only a few reports of growing chondromas during pregnancy—mainly in the skull—but there have been no reports of chondromas in the sternum.

Chondromas are common benign tumors arising from the hyaline cartilage. Most frequently, chondromas occur in the small bones of the hand or the feet, followed by the long tubular bones (femur and humerus). Appearance on flat bones such as ribs, the sternum, or the pelvis is rare. Chondromas equally affect males and females, and incidence does not appear to be related to age. Symptoms are a palpable mass that sometimes causes pain and pathologic fractures. Recommended treatment depends on the location, but curettage or excision is often used with a low rate of recurrence (in a few cases as a chondrosarcoma). In this paper, we report a case of a chondroma of the sternum growing during pregnancy in a 32-year-old female.

Case Report

In February 2015, a 32-year-old female, gravida 2, para 1, was admitted to our hospital with a swelling mass of the sternum. The tumor was first noticed when the patient was 14 years. For years, the mass did not grow and did not cause any symptoms. The patient got pregnant a second time (the first time she had an abortion) at the age of 30 years. The male baby was carried to full term in December 2013 and delivered via caesarian section. After delivery, the patient lost weight and noticed that the sternal tumor had grown. During lactation, the tumor was still growing, and the patient experienced paresthesia around the tumor. She was still breast feeding when she presented to our hospital.

Clinical examination showed a 3 cm indolent hard tumor parasternal to the left costal arc. A computed tomography (CT) scan was performed and showed a tumor measuring 10 × 8 × 7 cm with an intrathoracic bulk, compressing the heart and the upper margin of the liver (Fig. 1). Spirometry indicated no obstructive or restrictive dysfunction of ventilation. Because the nature of the tumor was unknown, a fine needle aspiration was performed. The histology of the tumor indicated a chondroma.

Fig. 1. CT scan showing the tumor of the sternum compromising the heart and the upper part of the left liver lobe. (a) axial plane (b) coronal plane. CT: computed tomography.

The tumor was removed under general anesthesia. The patient was placed in a dorsal position. Median laparotomy and thoracotomy incisions were made. The tumor was removed, including a part of the left seventh rib, the processus xiphoideus, and 1 cm of the caudal sternum. As recommended in the literature, the reconstruction was done with a prolene mesh using a sublay technique.

The pathological and histopathological examination of the tumor showed an encapsulated tumor with hyperplastic cartilaginous parts without mitosis, atypical cells, sclerotized matrix, or necrosis (Figs. 2 and 3). There was no infiltrative growth, so the tumor was confirmed to be a chondroma of the processus xiphoideus.

Fig. 2. Macroscopic aspect of the resected chondroma: cartilage with intact capsule on the cutting area with a grey/white tumor.

Fig. 3. Pathologic specimen: chondroma in different magnifications (hematoxylin–eosin staining): hyperplastic cartilage shown partially with severe regressive changes, fibrosis, and local necrosis. (Magnification: (a) × 50, (b) + (c) × 100).

Postoperative vacuum drainage of the wound was performed for 2 days. No seroma or hematoma occurred. The patient continued breast feeding during hospitalization. No long-term complications were evident at the 12-month follow up.

Discussion

The association between pregnancy and the rapid growth of meningioma has long been appreciated, but its basis remains disputed. Tumor growth during pregnancy or lactation has been a focus of study for a long time. For example, in 1922, Kross³⁾ published a first review concerning tumor growth and correlation with pregnancy. His own investigations with implanted tumors in pregnant and non-pregnant rats did not result in any tumor growth. In 1983, Donegan¹⁾ did a comprehensive review of the literature and summarized that it is difficult to demonstrate that pregnancy influences tumor growth in common cancers. However, there are consistently appearing case reports about benign or malignant tumors growing or developing during pregnancy. The most frequently reported malignancy is breast cancer.¹⁾ However, benign tumors—such as meningiomas—are also reported to develop during pregnancy. There are also some reports about growing chondromas, mainly in the skull.^4,5)

Several potential mechanisms for this phenomenon are being discussed. King et al.⁶⁾ suggest that engorgement of blood vessels may increase growth of intracranial tumors in pregnant women. Weyand⁷⁾ proposes that it is due to an increase in intracellular fluid. There are also some studies revealing an association between malignant tumor growth and pregnancy due to the tolerance of the intact immune system against antigenic tissue.⁸⁾

The most researched fact is tumor dependence on gestational hormones. There are some studies showing tumors expressing progesterone and estrogen receptors and growing during pregnancy (e.g., breast or ovarian cancer and meningioma^9,10)). Chondromas and chondrosarcomas also express receptors, especially for 17bestradiol.¹¹⁾ It has been shown that E2 promotes chondrocyte proliferation and accelerates the growth of both male and female chondrocytes in all stages of maturation.¹²⁾

Conclusion

Benign lesions during pregnancy are not often a study focus, except intracranial tumors. This may be because a growing mass causes symptoms due to its suppressing growing. There is not often a need to treat these patients before delivery, except where the tumor endangers maternal or fetal health or has the potential to cause irreversible damage, as is the case with intracranial benign tumors.

Disclosure Statement

There are no potential conflicts of interest arising from associations with commercial or corporate interests in connection with the work submitted. No funding was provided.