Extraordinary presentation of elastofibroma dorsi after a thoracotomy procedure

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Extraordinary Presentation of Elasto

ﬁbroma

Dorsi After a Thoracotomy Procedure

Ebru Ozan, M.D., Egemen Akincioglu, M.D., Tevﬁk Kaplan, M.D., Gokce Kaan Atac, M.D.

Conflict of interest: The authors certify that they have no affiliations with or involvement in any organization or entity with anyfinancial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.

Funding: This research did not receive any speciﬁc grant from funding agencies in the public, commercial, or not-for-proﬁt sectors.

Acknowledgements: None.

Abstract: Elastofibroma dorsi is a reactive pseudotumor of connective tissue, typically located in the infrascapular region. Awareness of this benign entity is crucial for radiologists, as well as clinicians, to avoid misdiagnosis and potential patient harm. In this report, we present clinical and imaging_{findings of an} elastofibroma dorsi after a thoracotomy procedure.

Keywords: Elastoﬁbroma dorsi-Posterior chest wall-Metastasis-Computed tomography-Imaging

Author afﬁliations: Ebru Ozan, Department of Radiology, Ufuk University School of Medicine, Ankara, Turkey; Egemen Akincioglu, Department of Pathology, Ufuk University School of Medicine, Ankara, Turkey; Tevﬁk Kaplan, Department of Thoracic Surgery, Ufuk University School of Medicine, Ankara, Turkey; Gokce Kaan Atac, Department of Radiology, Ufuk University School of Medicine, Ankara, Turkey

Correspondence: Ebru Ozan, Department of Radiology, Ufuk University School of Medicine, Doctor Ridvan Ege Training and Research Hospital, Mevlana Bulvarı (Konya Yolu) No:86-88, 06520 Balgat, Ankara, Turkey., email:ebrusanhal@yahoo.com ª 2017 by the National Medical Association. Published by Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.jnma.2017.09.005

INTRODUCTION

E

lastofibroma dorsi (ED) is a benign soft-tissue pseudotumor that is most commonly located in the deep dorsal region between the thoracic wall and the lower third of the scapula.1,2Although it is usually asymptomatic, it can cause swelling or pain. ED shows a number of typical imagingfindings on modalities such as ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) and most cases can accurately be diagnosed on the basis of these findings.3,4 However, differential diagnosis of this benign lesion may require additional effort and caution, especially in patients with a history of malignancy. Awareness of imaging findings and metabolic characteristics of ED is crucial for radiologists, as well as clinicians, to avoid misdiagnosis and potential patient harm. In this report, we present clinical and imagingfindings of ED mimicking metastasis in a patient with the history of neuroendocrine tumor of lung.

CASE REPORT

A 50-year-old woman presented with pain at the thora-cotomy site after a 6-month period following the surgery that was performed for a pulmonary nodule, which was pathologically proven to be a well-differentiated pulmo-nary neuroendocrine tumor (typical carcinoid).

On physical examination, she had tenderness and pain on the operation site. On palpation there was an ill-deﬁned palpable swelling adjacent to the inferior pole of the right scapula. Chest CT revealed a mass on the right posterior chest wall protruding through the intercostal space, in a concordant localization with the patient’s pain and the previous site of thoracotomy (Fig. 1). The mass was mildly heterogeneous, composed of isodense areas compared to neighbouring muscle tissue and low-density areas consis-tent with fatty tissue. No signs of bone destruction and invasion were present.

When the patient’s preoperative chest CT examination was evaluated, bilateral subscapular masses consistent with ED were identified (Fig. 2). Additionally, positron emission tomography combined with computed tomography (PET/CT) imaging of the same period was also re-evaluated and bilateral mild uptake of 18F-fuorodeoxyglucose (18F-FDG) in consistent localisations with chest wall masses was seen. The maximum standardized uptake values (SUVmax) were 3 and 3.2 for the right and left masses, respectively. A final diagnosis of ED was made without any necessity of further radiologic investigations. However, considering the patient’s symptom, resection was scheduled by the surgeon. On thoracotomy, a soft tissue mass protruding through the intercostal space was resected. On microscopic examination, the lesion was composed of abnormal elasticfibers that have an irregular moth-eaten or serrated margins and it was confirmed to be an ED (Fig. 3).

DISCUSSION

ED,ﬁrst described in 1961 by Jarvi and Saxen, is a soft-tissue pseudotumor of the thoracic wall and is almost entirely located adjacent to the inferior pole of scapula.1It mostly presents in elderly females aged over 50 years and its incidence is 13%e17% based on the autopsy studies. However, pre-elastoﬁbroma-like morphologic changes were found to be present in 81% of the autopsies and in subjects over 55 years of age a prevalence up to 24% was

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reported.5 Regarding its high prevalence, physicians should be familiar with clinical and imaging ﬁndings of ED. Differential diagnosis of this benign lesion may require additional effort and caution, especially in patients with a history of malignancy.

US, CT and MRI are useful for diagnosis. However, CT ﬁndings are usually diagnostic, revealing an isodense mass compared to encompassing muscle with internal striations or dispersed areas of fat attenuation.4 Addi-tionally, ED may show a mild or moderate metabolic ac-tivity on PET/CT imaging, which should not be misinterpreted as abnormal metabolic behavior repre-senting malignant lesions.6In a recent report, a case with a right subscapular mass with inconsistent radiologic

ﬁndings for making a diagnosis of ED was presented.7

The lesion showed a moderate FDG uptake (SUVmax 3.5) in the PET/CT imaging and it was considered ma-lignant. The patient underwent surgery and pathological diagnosis of the lesion was consistent with ED. In another study, 10,350 consecutive PET/CT examinations of oncologic patients were retrospectively investigated and ED was identified in 176 patients as an incidental finding.8 Of these 176 patients, seven underwent surgery and the diagnosis of ED was confirmed histopathologically. Two and one of these patients had lung cancer and breast cancer, respectively and were operated due to suspected metastases and/or invasion of primary malignancy. The remaining four patients had also lung cancer and ED was incidentally detected during surgery. The authors concluded that although most cases with ED can be easily diagnosed on the basis of US, CT and MRI findings, misinterpretation as a neoplastic process should be avoi-ded, particularly in patients with lung, breast and chest wall malignant tumors.

Pulmonary carcinoids account for 0.5e5% of all lung tumors.9 Although the majority of patients with pulmo-nary carcinoid have an excellent survival, all carcinoids are malignant tumors with the potential to recur or metastasize.10Consequently, suspicion of metastasis was raised in the clinician’s mind initially, in the presented case. However, comparison to earlier imaging studies helped us to make aﬁnal diagnosis of ED that was later pathologically approved. To our knowledge, this is the ﬁrst report of a confounding ED case, that protrudes through the intercostal space after the thoracotomy pro-cedure and mimicks metastasis. We suspect that widening of the intercostal planes during the previous thoracotomy procedure might have led the protrusion of

Fig. 1. (a) Axial and (b) Reformatted coronal contrast-enhanced CT images of thorax in mediastinal window, show a well-deﬁned, mildly heterogeneous, right posterolateral chest wall mass (arrows).

Fig. 2. Axial contrast-enhanced CT image of thorax in mediastinal window demonstrates bilateral crescent-shaped soft-tissue masses located in subscapular regions consistent with ED (ﬁve-pointed stars).

EXTRAORDINARY PRESENTATION OF ELASTOFIBROMA DORSI

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ED and accompanying fatty tissue through the intercostal space.

ED has a high prevalence; nevertheless, it is often overlooked or may be misinterpreted as a neoplastic pro-cess. When a soft tissue mass located in subscapular region has typical imaging ﬁndings of ED in an asymptomatic patient, no further investigation is necessary. However, it may confound the diagnosis mimicking invasion, recur-rence or metastasis and should be kept in mind when making the differential diagnosis of a posterior chest wall tumor in a patient with a history of malignancy. Thus, awareness of imaging ﬁndings and metabolic characteris-tics of ED is crucial for radiologists, as well as clinicians, to avoid misdiagnosis and potential patient harm, as no treatment is necessary in the asymptomatic oncologic patient. Furthermore, it should be considered that ED

may alter its shape or localization after a thoracotomy procedure.

REFERENCES

1. Jarvi, O., & Saxen, E. (1961). Elastoﬁbroma dorse. Acta Pathol Microbiol Scand, 51(Suppl. 144), 83e84.

2. Nagamine, N., Nohara, Y., & Ito, E. (1982). Elasto_{ﬁbroma in} Okinawa. A clinicopathologic study of 170 cases. Cancer, 50, 1794e1805.

3. Brandser, E. A., Goree, J. C., & El-Khoury, G. Y. (1998). Elasto ﬁ-broma dorsi: prevalence in an elderly patient population as revealed by CT. AJR Am J Roentgenol, 171, 977_e980.

4. Battaglia, M., Vanel, D., Pollastri, P., et al. (2009). Imaging pat-terns in elastoﬁbroma dorsi. Eur J Radiol, 72, 16e21.

5. Giebel, G. D., Bierhoff, E., & Vogel, J. (1996). Elasto_{ﬁbroma and} pre-elasto_{ﬁbroma- a biopsy and autopsy study. Eur J Surg} Oncol, 22, 93_e96.

6. Fang, N., Wang, Y. L., Zeng, L., et al. (2016). Characteristics of elastoﬁbroma dorsi on PET/CT imaging with18F-FDG. Clin Im-aging, 40, 110e113.

7. Lococo, F., Cesario, A., de Franco, S., et al. (2014). Is 18FDG PET/ CT evaluation really useful in the diagnosis of elasto_ﬁbroma dorsi? Rev Esp Med Nucl Imagen Mol, 33, 62.

8. Erhamamci, S., Reyhan, M., Nursal, G. N., et al. (2015). Elasto ﬁ-broma dorsi incidentally detected by18F-FDG PET/CT imaging. Ann Nucl Med, 29, 420e425.

9. Langfort, R., Rudzinski, P., & Burakowska, B. (2010). Pulmonary

neuroendocrine tumors. The spectrum of histologic subtypes and current concept on diagnosis and treatment. Pneumonol Alergol Pol, 78, 33e46.

10. Canizares, M. A., Garcia-Fontan, E. M., Rivo, J. E., & Gonzalez-Pineiro, A. (2005). Local recurrence and metastatic disease in a typical N1 carcinoid bronchial tumour. Clin Transl Oncol, 7, 216_e218.

Fig. 3. Microscopic appearance of the lesion. Elastic stain (Elastica Von Gieson) x 400, reveals deeply staining, branched and unbranchedﬁbers that have a central dens core and irregular moth-eaten or serrated margin.

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