Surgical resection of a well-differentiated inflammatory liposarcoma of the middle mediastinum: a case report

Abstract

Liposarcomas are the most common type of mesenchymal neoplasm in soft tissue sarcomas.Although they frequently develop at the lower limbs or retroperitoneum, cases arising from the mediastinum are rare. Furthermore, the incidence of the inflammatory subtype of well-differentiated liposarcoma is known to be low. We experienced a case of a middle mediastinal liposarcoma in a 68-year-old woman.The tumor, which was completely resected, was 92 mm in diameter. The tumor consisted of two different imaging components that showed different growth and which were diagnosed as the lipoma-like subtype and inflammatory subtype of well-differentiated liposarcoma. To the best of our knowledge, this is the first report of a well-differentiated inflammatory liposarcoma arising from the middle mediastinum. Although positron emission tomography (PET) revealed no significant difference between the two components, the FDG accumulation of the upper part tended to be stronger (SUVmax =3.67) in comparison to the lower part (SUVmax =2.55) ( Figure 2C,2D). Fine-needle aspiration cytology was performed by endobronchial ultrasonography (EBUS); however, the diagnosis could not be determined. Since the infection tests were also negative, the possibility of an infectious lesion was denied. We therefore planned the surgical resection of the tumor for diagnostic and therapeutic purposes. The operation was postponed for 4 months based on the patient's wishes. During this time, the high absorption component on the head side grew to 80 mm, while the low absorption part on the caudal side showed little change in size ( Figure 1C,1D). The doubling time of the high absorption component was calculated as 76 days.As the tumor invasion to superior vena cava was suspected from the preoperative image findings, we judged that a median sternum approach was needed in preparation for the angioplasty of superior vena cava. We performed tumor exeresis and thymectomy by a median sternotomy. During the surgery, the tumor was found to have adhered to the superior vena cava, trachea, brachiocephalic artery, and aortic arch, but there was no macroscopic infiltration. Tumor removal was performed after exposing and peeling of vessels without combined resection. There was no The resected tumor was 92 mm in size, and was composed of two solid components, which had different color tones (Figure 3A,3B). A pathological examination revealed that the component that showed low-absorption on CT (on the caudal side) consisted of various large and small adipocytes, accompanied by fibrous septa with some atypical cells. It was diagnosed as the lipoma-like subtype of well-differentiated liposarcoma ( Figure 3C). The component that showed high-absorption on CT (on the head side) showed the proliferation of oval to spindleshaped or polygonal cells with hyperchromatic nuclei that were arranged in a vaguely fascicular or haphazard pattern with fibro-collagenous, accompanied by myxoid stroma, dense lymphocytic inflammatory cell infiltration and lymphoid aggregates. Diagnosis o...

Resection of a giant mediastinal atypical lipomatous tumor involving the esophagus

“…Mediastinal liposarcoma can be huge when detected due to its slow-growing nature [ 3 ]. Previous reports have described successful resection of large mediastinal liposarcomas, where several surgical approaches have been described [ 5–7 ]. In the majority of previously reported cases in which tumors were situated in the anterior mediastinum, an anterior approach such as median sternotomy or clamshell thoracotomy was employed [ 5 , 7 ].…”

“…Previous reports have described successful resection of large mediastinal liposarcomas, where several surgical approaches have been described [ 5–7 ]. In the majority of previously reported cases in which tumors were situated in the anterior mediastinum, an anterior approach such as median sternotomy or clamshell thoracotomy was employed [ 5 , 7 ]. For the resection of middle/posterior mediastinal liposarcomas, unilateral thoracotomy was often adequate for full exposure of the tumor [ 8 ].…”

Prepubic inflammatory liposarcoma presenting as urosepsis

“…This entity was first described in 1997 in case series describing unusual variants of liposarcomas which mimic lymphoid disorders on histopathology. [ 1 2 ] Cases reported in the literature are predominantly retroperitoneal in location,[ 3 ] with a few reports in the paratesticular,[ 4 5 ] scrotal,[ 6 ] or thoracic[ 7 8 ] location. Inflammatory liposarcoma in the prepubic location has never been reported.…”

Intense FDG Uptake in Well-Differentiated Inflammatory Liposarcoma of the Retroperitoneum

“…2 Well-differentiated inflammatory liposarcoma is a rare low-grade liposarcoma, accounting for only about 2% of all liposarcomas. [3][4][5][6] Histologically, well-differentiated inflammatory liposarcoma contains abundant inflammatory infiltrates. When the inflammatory infiltrates predominate, the lipomatous component of the tumor can easily be overlooked, resulting in misdiagnosis.…”

“…2,7 Well-differentiated inflammatory liposarcoma may have minimal or no detectable fat as was seen in this case, due to extensive inflammatory infiltrates. 5,6 Liposarcoma grade correlates with SUV max of the tumor, and well-differentiated liposarcoma usually shows low-grade FDG uptake. [8][9][10] The FDG PET/CT findings of well-differentiated inflammatory liposarcoma have rarely reported.…”