Annals of Case Reports (ISSN: 2574-7754)

case report

  PDF Download

Symptomatic Pleural Lipoma: A Case Report and Literature Review

Harry Gaffney*, Sonja Klebe

College of Medicine and Public Health, Flinders University, Adelaide, Australia

*Corresponding author: Harry Gaffney, College of Medicine and Public Health, Flinders University, Adelaide, Australia

Received Date: 06 January 2023

Accepted Date: 10 January 2023

Published Date: 12 January 2023

Citation: Gaffney H, Klebe S (2023) Symptomatic Pleural Lipoma: A Case Report and Literature Review. Ann Case Report. 8: 1122. DOI:https://doi.org/10.29011/2574-7754.101122

Abstract

Pleural lipomas are extremely rare benign, slow-growing tumours of mesenchymal parietal pleura origin with the capacity to extend into sub pleural, pleural or extra pleural spaces. They present with a myriad of mild to severe compressive-related symptoms. Diagnosis can be made via CT, but histopathological intervention is required if the mass exhibits fibrous stroma or dystrophic ring-type calcifications to differentiate between similarly presenting fat-containing intrathoracic masses diagnostically. Watchful waiting and clinical and radiological follow-up are appropriate for those with small and asymptomatic lesions, the elderly, and populations unsuitable for surgical resection. However, surgical resection via thoracotomy has good outcomes and should be considered for diagnostic and therapeutic benefit to those with symptomatic pleural lipoma. Due to the rare occurrence of pleural lipoma, they have only been reported sporadically in the literature. As a result, it is important to report every identified case of pleural lipomas to improve diagnostic accuracy and patient health outcomes. Therefore, we report a case of a pleural lipoma on a chest radiograph (CXR) in a 28-year-old female presenting with localised right chest discomfort.

Introduction

Lipomas are common benign tumours of the skin and subcutaneous tissue [1]. They occur with an annual incidence of 1 per 1000 people [1,2]. Pleural lipomas are rare and are usually found at the mediastinal, bronchial and pulmonary levels [3,4]. Because pleural lipomas develop slowly, most patients often remain asymptomatic [5,6]. As a result, pleural lipomas are generally found incidentally on chest radiographs or computed tomography (CT) examinations [4-8]. Although pleural lipoma is a benign tumour, when symptomatic, it should be completely resected, where possible, for diagnostic and therapeutic perspectives [3]. Due to the rare occurrence of pleural lipoma, they have only been reported sporadically in the literature. As a result, it is important to report every identified case of pleural lipomas to improve diagnostic accuracy and patient health outcomes. Therefore, we report a case of a pleural lipoma on a chest radiograph (CXR) in a 28-year-old female presenting with localised right chest discomfort.

Case Presentation

A 28-year-old female presented to their general practitioner (GP) with localised right-sided chest discomfort. A routine CXR showed a pleural-based opacity at the right mid and lower zone with displacement of the adjacent right middle and right lower lobe measuring 11x3x9cm. A follow-up computerised tomography (CT) chest scan revealed the same (Figure 1). The patient underwent a core biopsy of the lesion at a metropolitan hospital for histopathological investigation. From a microscopic perspective, this revealed morphologically unremarkable fibro connective and adipose tissue. As the sample was too small to render a definitive diagnosis, a right thoracotomy was performed to remove the lesion entirely for diagnostic precision completely. This revealed multiple small fatty lobules on the free edge of the lung and a large mass arising from the middle lobe attached to the diaphragm, mediastinum, and chest wall. The mass and fat lobules were excised utilising a combination of blunt and diathermy dissection alongside significant wedge resection of the middle lobe. Once removed, the total dimensions of the mass were 135 x 115 x 35 mm, weighing 206.3 grams. Macroscopically, the tumour consisted of a fatty lesion seen intimately associated with portions of the lung, demonstrating two staple margins (Figure 2). The smaller lung portion measured 75 x 15 x 10 mm in depth, and the larger 120 x 50 x 15 mm in depth. The opposite surface demonstrated a smooth surface covering a portion of the specimen. However, most of the area showed exposed lobulated fat. The specimen was transversely sectioned, and the cut surface demonstrated a general fatty appearance, with focal areas showing a fibrous appearance. The fatty lesion showed a smooth edge where it abuts the lung, with no evidence of lung infiltration. It also showed a smooth contour that abuts the strip of smooth tissue on the other face. The lung showed a minimum clearance of 4 mm from the fatty tumour. At least eight fatty lobules were identified macroscopically at the free edge of the right lower lung lobe (Figure 3). These lobules were up to 9 mm in maximum dimension, including a focus of heterologous differentiation in the right anterior chest wall biopsy. The cut surface demonstrated scattered pale areas (Figure 3). However, no solid nodules were identified. Microscopically and histologically, the samples comprised lung portions attached to a well-demarcated, encapsulated lipomatous tumour. It demonstrated extensive central coagulative necrosis and degeneration but no tumour-type necrosis (Figure 4). At its periphery, where more viable material was appreciated, there was a mild and patchy infiltrate of interstitial inflammatory cells, which included foamy histiocytes and scattered lymphocytes. Occasional areas showed a lobulated appearance, with delicate fibrous septa extending through the parenchyma. Plump spindle cells were occasionally observed in these regions, showing elongated nuclei with bland, finely granular chromatin. No increased or atypical mitotic activity was identified. A fibro-inflammatory response was appreciated where the tumour abuts the lung, but no extension into the lung parenchyma was identified. The lung itself was unremarkable, and the lung margin was well clear. Ancillary molecular studies were also performed on fresh tissue, which did not detect amplification of MDM2 on Fluorescent in situ hybridisation (FISH) analysis. The macro and microscopic appearances were those of a lipomatous neoplasm with no evidence of MDM2 amplification, in accordance with a benign pleural lipoma.

 

Figure 1: A chest CT showing a pleural-based opacity at the right mid and lower zone with displacement of the adjacent right middle and right lower lobe measuring 11x3x9cm.

 

Figure 2: Excised pleural lipoma measuring 135 x 115 x 35 mm and weighing 206.3 grams.