2024, Number 4
Chondromyxoid fibroma of the clavicle. Case contribution and classification proposal for clavicular resections
Full text
10.35366/117678
Language: English
References: 36
Page: 244-249
PDF size: 348.60 Kb.
ABSTRACT
The clavicle is an uncommon site for bone tumors; if it is a chondromyxoid fibroma, it is even more so. Social circumstances and alterations in the dynamics of health systems during the COVID-19 pandemic generated a delay in the diagnosis and treatment of many patients. We present the case of a 13-year-old female patient with a large neoplasm located in the left clavicle. After a complete imaging study, two biopsies were performed, diagnosing chondromyxoid fibroma. Radical claviculectomy without reconstruction is planned and performed. The clinical and functional results were excellent. The importance of the case lies in the fact that it corresponds to the tenth clavicular chondromyxoid fibroma reported in literature, and possibly the largest resected.INTRODUCTION
The clavicle is a very rare site for bone tumors1,2 and the majority of them are malignant lesions1,3,4 including metastatic bone disease.5 The incidence of tumors of the clavicle is reported of less than 1%,2,4-7 therefore, surgical experience for the treatment of clavicular tumors is usually limited.
The clavicle is an S-shaped, slender and subcutaneous bone that is connected to the sternal shaft and the acromion, which play an important part in constituting the sternoclavicular and acromioclavicular joints, respectively.8 The clavicle represents an important element in the anatomical and functional conjunction between the shoulder girdle and the thorax, and consequently with the axial skeleton.
The clavicle is an unusual bone from the perspectives of its embryology, morphology, localization, and function. It is the first ossified bone in the embryo; probably at five months2,9 and ossifies by membranous ossification.2,5 Clavicle contains two primary ossifications centers and only one secondary ossification center;2 it has no significant medullary cavity.2,5,6 The clavicle has sparse vascular supply with minimal red marrow surrounded by thick cortices of compact bone;5,6,9 it is the only bone of the long bones whose anatomical position is on the horizontal axis.2,5,6 Clavicle acts as a link between the upper limbs and the thorax, connecting the axial to the appendicular skeleton5 and shares its oncological characteristics with flat bones and not with other long bones.4
The importance of clavicular tumors and their treatment derive from their particular anatomical location relating to structures of vital importance. Neoplasms of the periclavicular area and the neck, are considered with extracompartmental location;10 there are no anatomical barriers to tumor extension. Fortunately, the clavicle is a bone that can be resected without causing significant disability.1
The most common tumors located at clavicle are: eosinophilic granuloma, bone metastasis and plasma cell myeloma.6 Other common neoplastic lesions include aneurysmal bone cyst, osteochondroma, Ewing sarcoma, chondrosarcoma and osteosarcoma. Some tumors such as chondrosarcoma, usually occur in sternum and scapula;11-14 when they extend extra-articularly, at least one clavicular segment should be resected en bloc with the originally affected area. Systematically, chondromyxoid fibroma is not considered as presumptive diagnosis for tumors that involve the clavicle.
Chondromyxoid fibroma has been defined by World Health Organization in 2020 as a benign lobulated cartilaginous neoplasm with a zonal architecture composed of chondroid, myxoid and myofibroblastic areas.15 This lesion represents less than 1% of all primary bone tumors16-18 and less than 5% of benign chondrogenic bone tumors.16
Chondromyxoid fibroma of the clavicle is exceedingly rare. After an exhaustive targeted search, Arora et al19 were able to find six cases reported in the literature, and the mention of two more in reviews focused on the diagnosis. As far as we have found, the case contributed by Arora et al19 is the most recently reported. Under this context, the objective of the present paper is to present the tenth case of chondromyxoid fibroma located in the clavicle, and possibly the largest resected one.19-27
CASE PRESENTATION
We present the case of a 13-year-old female patient referred to the Pediatric Orthopedics Service of the High Specialty Medical Unit in Traumatology and Orthopedics of the Northeast National Medical Center, belonging to the Mexican Social Security Institute, in Monterrey, Mexico. Upon admission, the patient had a history of pathological fracture of the left clavicle, since this event, progressive growth of a mass with neoplastic characteristics has occurred at the expense of the clavicle; a biopsy diagnosed chondromyxoid fibroma. The late reference to our hospital derived from the alterations generated in the health system by the COVID-19 pandemic situation. Once in the Pediatric Orthopedics Service, her general blood tests and imaging studies are updated.
Clinically, a firm mass is observed in the left clavicular area whose dimensions are 16 × 12 × 13 centimeters. An important collateral venous network is evident, and palpation does not generate pain. The scar from the previous open biopsy is located longitudinal to the clavicular axis.
By conventional radiology, the absence of the clavicle was observed with its replacement by a soft tissue mass with neoplastic characteristics. Computer tomography (Figures 1 and 2) and magnetic resonance imaging (Figure 3) show a neoplastic lesion which replaces the left clavicle and generates compression and vascular displacement. No evidence of sternal and/or acromial involvement is seen. The lesion rests on the first and second left ribs, however tumor involvement of it is not proven due to continuity. Both studies showed tracheal and thyroid shift to the right and the neurovascular structures of the neck (internal and external jugular veins, subclavian vein, common carotid artery and brachial plexus) are shown compressed and displaced. By magnetic resonance imaging, T1-weighted sequences showed isointensity to muscle, and T2-weighted sequences showed heterogeneous hyperintensity (Figure 3).
After the complete review of the case, and considering the rarity of the diagnosis and the dimensions of the tumor mass, a second open biopsy is performed continuing the axis of the first. Chondromyxoid fibroma was diagnosed again. Total claviculectomy (radical resection of the clavicle) without reconstruction is then planned, and prior signing of the corresponding informed consent, was performed. The patient's transoperative and postsurgical hemodynamic status was stable. There were no neurovascular sequelae in the immediate postoperative period. The healing process of the surgical wound was carried out without major complications. The histological study of the surgical specimen was consistent with that of the two biopsies previously performed (Figure 4).
With one year of follow-up, the patient is asymptomatic, without clinical and imaging data of recurrence, and without functional limitation. Being a neoplastic clinical situation, the methodology to evaluate the functional postoperative result was through the Functional Score of the Musculoskeletal Tumor Society (MSTS score)28 that evaluates six domains scored on a 0 to 5 scale and transformed into an overall score ranging from 0 to 100% with higher score for better results: pain, functional activity, hand positioning, dexterity, lifting ability and emotional acceptance. Personal satisfaction and functional result, were completely satisfactory: 30/30 (Figure 5).
DISCUSSION
Clavicular tumors may be associated with nonspecific symptoms such as local pain, swelling, or shoulder stiffness. Owing to the rarity of such tumors and lack of specific symptoms, diagnosis can be delayed.7 Specifically, in the case reported in this paper, social pandemic disruptions played an important role in the dimensions that the neoplasm reached.
Chondromyxoid fibroma can occur at almost any skeletal site. It is most frequent in the long bones, most often the proximal tibia and distal femur; flat bones are affected in approximately 25% of cases.15 The differential diagnosis of chondromyxoid fibroma is mainly with chondroblastoma, enchondroma and low-grade chondrosarcoma. Immunohistochemistry and diagnostic molecular pathology are generally not needed for diagnosis. The cartilaginous nature of this tumor is reflected by immunopositivity for S100. In selected cases, identification of the exceedingly specific upregulation of GRM1 expression in chondromyxoid fibroma could be a strong diagnostic adjunct in distinguishing this entity from its mimics.15
Clavicular chondromyxoid fibromas are excessively uncommon and practically have been only described as case reports in the literature.
The reported case differs from those found in the literature mainly due to its dimensions and the resulting surgical complexity for its resection. Generally, experience in total claviculectomy is scarce, even in highly specialized centers.
The clavicle can be divided into three segments: sternal end, middle segment and acromial end. Existing classifications for shoulder girdle resections29-34 do not satisfactorily consider the clavicle as a leading bone in the shoulder girdle, potentially carrying neoplastic pathology. The clavicle, like the rest of the skeletal structures, can be treated by intralesional or marginal resections, however under certain clinical circumstances including the case that we are contributing to the literature, wide or radical resections are required. Given the low incidence of clavicular tumors and resections due to oncological etiology, as well as considering the articular and non-articular relationships of the clavicle, in the present paper we also propose, for classification purposes, dividing the clavicle into 3 thirds with the possibility of extending the resection extra-articular towards the sternum in the medial third, to rib in the middle third, and / or to scapula in the lateral third. Based in this proposal, in this case the resection performed corresponds to a type I + II + III resection (likewise corresponding to a radical resection of the clavicle under the parameters described by Enneking et al).10,31 In some cases, given the need to extend towards the sternum, rib and/or scapula, the corresponding segment would be accompanied by the letter E (Extended) (Figure 6).
Tumors located in the clavicle can involve the entire clavicle.2 Total or subtotal excision of the clavicle is rarely associated with a clinically significant loss of function,1 however many sequels such as shoulder dropping, postoperative pain, limited motion of the shoulder joint, reduction of muscular strength, neurologic function deficit, and restriction of daily activities have been described.8,35 Fortunately, these complications and sequelae did not occur in the reported case.
Different methods as vascularized fibular graft, bone cement prosthesis and customized 3-D printed titanium prosthesis have been described to reconstruct the clavicle and its anatomical-functional environment, however, and agree with Chen et al (2018)36 and Atalay et al (2020),35 we consider that reconstruction after claviculectomy is unnecessary and can be associated with the increase of the incidence of different complications.
CONCLUSIONS
Clavicular tumors are uncommon and chondromyxoid fibroma in the clavicle is exceedingly rare. A late diagnosis makes surgical treatment difficult, however, clavicular resections are not associated with important functional sequelae. Surgery is still the main treatment modality for primary clavicular tumors and tumorous conditions. In most orthopedic centers, experience in the treatment of clavicular tumors is usually minimal. A classification system for clavicular resections facilitates understanding of the characteristics of a neoplasm, as well as the treatment to be performed. The close anatomic relationship between the clavicle and certain important vascular structures, makes neoplastic resections difficult; fortunately, the clavicle is considered as a dispensable bone. In general terms, the experience in the treatment of clavicular tumors and partial, total and extended claviculectomy, is very scarce.
REFERENCES
Hogendoorn PW, Bloem JL, Bridge JA. Chondromyxoid fibroma. In: WHO Classification of Tumours Editorial Board. Soft tissue and bone tumours. Lyon (France): International Agency for Research on Cancer; 2020. WHO classification of tumours series. 5th Edition, Volume 3, 2020: 362-364. World Health Organization. https://publications.iarc.fr/588
Malawer MM, Meller I, Dunham WK. Shoulder girdle resections for bone and soft tissue tumors: analysis of 38 patients and presentation of a unified classification system. In: Yamamuro T (ed): International Symposium on Limb Salvage in Musculoskeletal Oncology. New York, Springer-Verlag. 1988: 519-530.
AFFILIATIONS
1High Specialty Medical Unit in Orthopedics and Traumatology. Northeast National Medical Center. Mexican Institute of Social Security. Monterrey, Mexico
2Musculoskeletal Tumors. Attached Physician to Hip and Pelvic Surgery Service
3Chief of the Pediatric Orthopedics Service
4Attached Physician to the Pediatric Orthopedics Service
5Resident of Orthopedics and Traumatology
6Chief of Pathology Service.
Conflicts of interests: The authors declare that they have no conflicts of interest.
CORRESPONDENCE
Dr. Luis Jair Sánchez-Torres. E-mail: dolorarticular@gmail.comReceived: 02-12-2024. Accepted: 05-30-2024.