Surgical Management of Symptomatic Bilateral Elastofibroma Dorsi: A Case Report and Literature Review

Introduction

Elastofibroma dorsi (ED) is a type of benign thoracic tumor. It typically arises near the inferior angle of the scapula, deep to the latissimus dorsi and rhomboid major muscles [1]. ED is a rare, non-encapsulated tumor in which elastin fibers proliferate within a stroma of collagenous and fatty connective tissues. Jarvi and Saxen first described a case of ED in 1961 [2,3]. The incidence rate of ED is approximately 1% to 2% of all primary thoracic wall tumors [4]. The prevalence of ED rises with age, reaching up to 24%, and occurs more commonly in women, especially during their fourth and sixth decades of life [1,5,6]. While most cases are unilateral, around 10% to 30% of patients present with bilateral involvement [7,8]. Clinically, it manifests as an ill-defined mass around the inferior pole of the scapula, often associated with stiffness, swelling, discomfort, cracking sensations, and, on occasion, pain [3,7]. The exact pathogenesis remains uncertain. Some authors suggest that ED is a reactive process triggered by repetitive mechanical friction between the scapula and the thoracic wall, which causes fibroelastic tissue to proliferate excessively because of repeated microtraumas [8,9]. In this case report, we discuss a case of bilateral symptomatic elastofibroma dorsi.

Case Report

A 46-year-old man, who had undergone an abdominoplasty and a sleeve gastrectomy but otherwise had an unremarkable medical history, presented with a swelling on his left upper back that had persisted for over 1 year. The swelling was small and painless at first, but it gradually grew larger and started to hurt during the 4 months before the clinic appointment. The patient reported that occasionally the swelling reduced spontaneously and the pain also went away. He denied seeing any other lumps on his body. He was also experiencing sporadic back swelling on the right side. He denied experiencing any constitutional symptoms like night sweating, fever, or weight loss. Upon examination, the left scapula’s lower pole showed a hard, immobile swelling that decreased below the scapula. Inspection revealed no swelling on the right side; however, the abduction maneuver revealed a substantial lump.

Laboratory findings were normal, and preoperative MRI revealed bilateral ill-defined lesions in the subscapular and infrascapular regions, located deep to the latissimus dorsi and serratus anterior muscles. The lesion on the right measured 13×3.5×8.5 cm and 10×3×8 cm on the left, both displaying a heterogeneous matrix with intermediate signal on T1WI and T2WI, and high signal intensity foci with suppression on fat-saturated sequences (Figure 1). Following contrast administration, the lesions showed modest enhancement. Clinical and radiological results led to the diagnosis of elastofibroma. The patient was scheduled to have the bilateral upper-back elastofibromas excision, and the preoperative chest X-ray revealed normal lung aeration without any pneumothorax or pleural effusion.

Under general anesthesia, the patient was placed in the lateral decubitus position with a slight abduction of the arm, and complete excision of both masses through bilateral posterolateral subscapular incisions (Figure 2). Intraoperatively, bilateral drains were inserted. The patient recovered without any complications and was discharged home on postoperative day 5 with a 7-day course of antibiotics. Three days following discharge, the drains were taken out. The patient’s discomfort had totally subsided by the end of the first postoperative week, and the symptoms that had been present were under control. On 12-month follow-up, the patient remained asymptomatic with no evidence of recurrence.

Discussion

Although often described in the literature as exceedingly uncommon, autopsy and imaging series suggest ED may be under-recognized. ED prevalence in patients over age 60 years is roughly 2% based on CT scans [10]. The prevalence rate of ED is higher in women than men. A Saudi Arabian study found that 36 out of 4435 individuals with a mean age of 76.6 years had ED confirmed by CT scan. Of them, 8 were male and 28 were female. Females were 3.3 times more likely to have the disease (77.8%) than males (22.2%), with a frequency of 0.8%. Out of these patients, 11 (30.56%) had bilateral ED and 25 (69.44%) had unilateral ED [5]. However, more recent surgical cohorts include substantial numbers of men. For instance, Scamporlino et al reported that among patients undergoing surgery for ED, 41% were males [11]. Furthermore, ED primarily affects females over 50 years of age and is rare in children [12]. The average age at diagnosis is 65 years, with a reported range of 48 to 82 years [5]. Bilateral presentation in ED is usually less common compared to unilateral presentation [7,8], and having several elastofibromas is thought to be uncommon [13]. Our case of bilateral elastofibroma dorsi manifested as back pain. Because of the lesion’s symptomatic character, gradual enlargement, and physical examination detectability, it was surgically removed.

Several pathogeneses have been postulated [14]. Chronic mechanical friction of the scapula against the thoracic wall was long posited, supported by its over-representation in manual laborers, but other factors such as vascular changes, collagen degeneration, or genetic susceptibility have been suggested [6,15]. In our case there was no history of heavy physical labor or family history, so an idiopathic or degenerative etiology is likely. Apart from biomechanical factors, immunological and genetic factors have also been documented as predisposing factors, as 32% of ED patients have a familial history [16]. Nagamine et al reported that 55 out of 170 clinicopathologically-verified ED cases had been detected in the same family lines, suggesting a favorable family history [17]. Thus, it is essential to get a thorough medical history and perform a thorough physical examination to prevent misdiagnosing ED as subacromial bursitis or a rotator cuff injury [18,19].

In most cases, EDs are asymptomatic and found incidentally on imaging [1,11]. When symptomatic, patients typically have dull ache or discomfort in the scapular region, often worsened by shoulder movement, and sometimes of a palpable click or scapular snapping [11,20]. Physical exam may show a soft or firm mass at the inferior scapular margin that becomes apparent with shoulder adduction and may disappear with abduction. In our patient, examination revealed a hard, non-mobile lump at the lower pole of the left scapula; the right-sided lesion was occult at rest and was only revealed when the arm was abducted. These findings align with other reports where ED is often missed at rest and elicited by scapular motion [20]. A clinically noticeable lump may be the initial sign of an ED greater than 5 cm. A deeply situated ED, however, is typically undetectable until it is 5 cm or larger [21]. In over 80% of cases, ED is situated in the subscapular area between the latissimus dorsi and rhomboid muscles. In 99% of cases, it is situated next to the thoracic wall, between the sixth and eighth ribs. However, ED has been documented in less than 1% of individuals in less common places, such as the stomach, eye, hand, inguinal region, greater omentum, greater trochanter, olecranon, tricuspid valve, foot, deltoid, axilla, and ischial tuberosity [22–24].

MRI is usually considered key diagnostic modality for ED. On MRI, lesions have an intermediate signal on T1 and T2, with linear high-intensity streaks on fat-sensitive sequences due to interspersed adipose tissue [3]. Furthermore, the signal from the lesion is not improved by gadolinium contrast injection. The MRI for our patient demonstrated bilateral poorly-circumscribed masses deep to the serratus anterior, with intermediate signal and multiple linear bright foci consistent with fat. On CT, EDs show a layered or speckled pattern of fibrous tissue and fat [25]. However, MRI is often considered the imaging modality of choice because it shows characteristics alternating pattern of fibrous and fatty tissue in ED. Regarding the necessity of biopsy, perspectives differ widely. To distinguish ED from sarcomatous lesions, the authors of previous research consistently advise undergoing a biopsy [26]. More recent research, however, indicates that if the lesion exhibits typical symptoms, imaging, especially MRI, is sufficient for diagnosis [15]. A biopsy is only carried out to confirm ED when a diagnosis cannot be made based on unusual MRI results. Although it can be used, fine-needle aspiration is insufficient to get a representative tissue sample.

Histological analysis in our case showed ill-defined, unencapsulated lesions related to elastofibroma composed of fibrocollagenous tissue with aberrantly broken elastic fibers and variable levels of adipose tissue. These fibers stand out when stained with EVG elastic (Figure 3). The quality of the histologic preparation was satisfactory, and no signs of cancer were found. One crucial characteristic that sets ED apart from other pseudotumors and neoplasms is the absence of atypia and mitotic activity [12]. According to our findings, MRI can adequately diagnose the lesion when interpreted in the context of relevant clinical signs, hence avoiding the need for a preoperative tissue diagnosis in most patients [19]. In terms of treatment, surgical resection is only necessary if the tumor is large enough to produce symptoms or if the diagnosis is uncertain. Criscione et al, in their case series of 13 ED cases, reported that surgery is necessary for symptomatic cases, whereas asymptomatic cases should be monitored clinically and radiologically [27]. Although there have been reports of recurrence, surgical excision is considered curative [13]. For example, a study by Chase et al reported that in 87.5% of the patients who underwent surgical excision for ED, there was complete resolution and there was no case of recurrence [28].

There have been reports of local tumor recurrence following partial excision [16]. For example, Mariño et al observed a 10% recurrence rate after an average postoperative duration of 47 months [29]. However, in some recent studies, no cases of recurrence have been reported [11,30]. The literature contains no reports of malignant transformation [31].

Radiotherapy may be considered, especially in cases that are unresectable due to their location. To prevent postoperative seroma, it is advised to drain the incision after surgery, use a compression garment, and immobilize the shoulder for 1 week [32].

Conclusions

ED is an uncommon benign tumor of the thoracic wall that typically develops beneath the rhomboid major and latissimus dorsi muscles, near the inferior angle of the scapula. Although most cases are unilateral, our patient presented with bilateral lesions. This case shows the importance of maintaining a high index of suspicion when evaluating scapular masses, particularly when symptoms fluctuate with shoulder movement. MRI continues to be the standard method for diagnosis, as it reliably demonstrates the pathognomonic admixture of fibrous and fatty tissue, thereby reducing the need for preoperative biopsy. Surgical excision remains the treatment of choice for symptomatic or enlarging ED. Our patient’s postoperative course confirmed the efficacy of marginal resection, with complete symptom resolution and no perioperative complications. The present case is distinctive for its bilateral symptomatic presentation in a relatively young male.