A giant infiltrating angiolipoma of the mediastinum: a case report
Liu et al. Journal of Cardiothoracic Surgery
A giant infiltrating angiolipoma of the mediastinum: a case report
Peng Liu 3
Wen-Cheng Che 2
Huai-Jun Ji 1
Zhong-Min Jiang 0
0 Department of Thoracic Surgery, Shandong Qianfoshan Hospital , Jingshi Road No.16766 Lixia, Jinan, Shandong , China
1 Weifang Medical College , Weifang , China
2 Shandong University School of Medicine , Jinan , China
3 Taishan Medical College , Taian , China
Background: Angiolipoma is a rare benign neoplasm composed of mature fatty tissue and multiple small abnormal blood vessels. Infiltrating mediastinal angiolipoma is an extremely rare tumor associated with delayed diagnosis. Case presentation: A 42-year-old woman was presented with 3-month history of mild chest tightness. Imaging of the chest showed a large mass with fat densities in the middle superior mediastinum. A presumptive diagnosis was a tumor of liposarcoma. The patient was scheduled for a thoracotomy. After the excision, the symptoms were relieved and histological study revealed that the tumor was an angiolipoma. The patient recovered very well and was discharged 7 days after the surgery. After 7 months of follow-up the patient was clinically well and asymptomatic. Conclusions: We described a giant infiltrating mediastinal angiolipoma and its removal, and discussed the tumor characteristics and prognosis. Although extremely rare, infiltrating angiolipoma should be considered in the differential diagnosis of mediastinum lesions. The prognosis after surgical management of our patient is favorable.
Infiltrating angiolipoma; Mediastinum; Thoracotomy
Mediastinal angiolipomas are extremely rare tumors
within the thorax, and only several cases have been
previously reported in the literature. The diagnosis and
prognosis of angiolipomas are based entirely on the
findings of histological evaluations. Angiolipoma has two
histologic types: infiltrating and non-infiltrating . We
report a rare case of giant infiltrating mediastinal
angiolipoma. To our knowledge, this is the first report of an
infiltrating angiolipoma in mediastinum.
A 42-year-old female presented with 3-month history of
mild chest tightness. Her medical history was
unremarkable. Physical examination found that her left arm
muscles were thicker than the contralateral ones (Fig. 1a).
Breath sounds on auscultation were diminished at the
upper left lung. Plain X-ray of the chest revealed a mass
in the superior mediastinum (Fig. 1b). Computed
tomography (CT) of the chest showed a mass, measuring
10 cm × 5.5 cm in size with fat densities in the middle
superior mediastinum (Fig. 2a). On the post contrast
images the tumor was slightly heterogeneously enhanced
and the adjacent blood vessel was surrounded by the
lesion with obscure boundary (Fig. 2b). Laboratory tests
This large infiltrating mass was considered a tumor of
liposarcoma. Taking into account the provisions of
China’s health insurance and the practice of local
surgeons, a biopsy during operation should be done to
determine the pathological type. The patient was
scheduled for a thoracotomy. During the operation, a
large mass, invaded the left subclavian artery and
brachiocephalic vein, was found in the anterior
mediastinum. Since it was very difficult to dissect the mass
completely from the mediastinal structures, especially
the left subclavian artery, an incomplete resection was
performed. Macroscopically, it was revealed a hard mass
of 10 cm × 6 cm × 6 cm in size with a gray-yellowish in
color and a sense of oily (Fig. 3a). Pathologic evaluation
demonstrated mature adipose tissue with many
hyperplastic blood vessels, being consistent with the typical
findings of angiolipoma (Fig. 3b). The patient recovered
very well and was discharged 7 days after the surgery.
Considering the incomplete resection, we recommened
that the patient undergo a strategic radiation therapy
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Fig. 1 a The left arm muscles were thicker than the contralateral ones. b X-ray of the chest revealed a mass in the superior mediastinum
Fig. 2 a CT scan of chest showed a 10*5.5 cm-sized mass (white
arrow) with fat densities in the middle superior mediastinum. b The
tumor was slightly heterogeneously enhanced and the adjacent
blood vessel was surrounded by the lesion with obscure
boundary(red arrow). The left chest and back muscles were thicker
than the contralateral ones
after 1 month of the surgery. After 7 months of
followup the patient was clinically well and asymptomatic.
Angiolipoma is a variant of lipoma exhibiting proliferating
capillaries admixed with mature adipocytes. Angiolipoma
was first defined by Bowen in 1912  and differentiated
from lipomas histopathologically by Howard in 1960 .
Angiolipoma has two histologic types: infiltrating and
non-infiltrating . Infiltrating angiolipomas are
characterized by a non-capsulated tumor and extend into
surrounding tissues. This case was a giant infiltrating
angiolipoma of 10-cm diameter located in the
mediastinum and invaded the adjacent tissues. Non-infiltrating
angiolipomas are encapsulated. Angiolipomas usually
present as painful or tender subcutaneous masses in
young adults. Infiltrating angiolipomas can also lead to
muscular pain and neural deficits . The thickened left
arm, in this case, may be the results of muscular
compensatory hypertrophy caused by a poor blood supply
resulting from the long-term compression of the left subclavian
artery by the large mediastinal mass.
Mediastinum lesions have a wide range of pathologic
features but a similar imaging appearance. The most
common tumors found in the anterior mediastinal
compartment are of thymic, lymphatic, or germ cell origin.
More rarely, neoplasms and other masses originating
from vascular or mesenchymal tissues may also be
found. Taking into account the patient’s age, the location
of the mass and its radiological appearance, the
differential diagnosis in this case could have included teratoma,
lipoma, and liposarcoma.
Teratoma is one of the most common tumors found
in the mediastinum, and mostly is located in the anterior
mediastinal compartment. Mediastinal teratomas are
Fig. 3 a Excised tumor, a 10*6*6 cm-sized hard mass with a gray-yellowish in color and a sense of oily. b H and E stained section showing
features of angiolipoma
often asymptomatic. When such symptoms as chest
pain, cough, dyspnea, or symptoms related to recurrent
pneumonitis are present, they are usually attributed to
mechanical effects. Mediastinal teratomas are
occasionally discovered incidentally on chest radiograph. The
enlarging teratoma can also result in local compression
symptoms that make the differential diagnosis more
challenging. But, in this case, bhCG, AFP and other
laboratory tests were normal, which did not support the
diagnosis of teratoma.
Lipomas are common benign mesenchymal tumors.
More than half of lipomas encountered by clinicians are
subcutaneous in location. But they may develop in
virtually all organs throughout the body. Numerous case
reports document the presence of lipomas in other, rare
locations, with these tumors having been found virtually
everywhere in the body. In rare instances, lipomatous
involvement of the structural components of the
mediastinum, including the airways and pleura, has also been
reported. In this case, the large tumor in the
mediastinum caused a chest tightness, and impinged on the
adjacent blood vessels, including the left subclavian artery
and brachiocephalic vein.
Liposarcomas are malignant tumors that arise from
adipocytes. They may recur locally and may metastasize
to distant organs. Fatty tumors with poor capsule of the
mediastinum should be considered to be potential
liposarcomas until proven otherwise. In addition,
liposarcomas most commonly arise in the posterior mediastinum,
as opposed to the anterior predilection of both lipomas
and teratomas .
There is no evidence that angiolipomas undergo
malignant transformation due to lack of atypia,
pleomorphism, or mitotic figures in angiomatous or adipose
tissues. Treatment of angiolipomas is complete surgical
excision for both infiltrating and non-infiltrating types.
In some cases, however, it is difficult for infiltrating type
of angiolipomas to be removed completely by surgical
approach. In this case, the recurrence rate is high and
postoperative radiotherapy may be needed .
A search for cases of mediastinal angiolipoma revealed
that only a limited number documented cases have been
reported. Kline in the year 1990 first reported a case of
non-infiltrating angiolipoma of the mediastinum. A CT
scan showed a large and soft-tissue components near
the esophagus . After his initial report, Ja-Young Choi
in 2000 also reported a case of posterior mediastinal
angiolipoma extending into spinal canal and showing
both fat and angiomatous features on CT scan . Luis
Gorospe in 2015 described a lipid-poor angiolipoma
within the posterior mediastinum in a patient with chest
pain . Occurrence of infiltrating angiolipomas of
mediastinum is extremely rare.
We report a case of extra-large infiltrating angiolipoma of
the mediastinum. Although extremely rare, infiltrating
angiolipoma should be considered in the differential
diagnosis of mediastinum lesions. In addition, the large
infiltrating mass in mediastinum may invade the surrounding
structures and the procedure of dissection and removal
may be very difficult. Clinicians should be aware of this.
This received no specific grant from any funding agency in pubic, commercial,
or not-for-profit sectors. Furthermore, none of the authors has any commercial
or financial involvement in connection with this study that represents or
appears to represent any conflict of interest.
Availability of data and materials
Informed consent was obtained from the patient prior to initiating the study.
The datasets supporting the conclusions of this article are available in the
repository of Ethics Committee for Clinical Research of Shandong Qianfoshan
PL, WCC and ZMJ participated in the care of the patient. PL and WCC
performed the literature review and drafted the manuscript. HJJ obtained
the pathological data. ZMJ was the surgeon-of-record. All authors read and
approved the final manuscript.
Ethics approval and consent to participate
The clinical study of the above mentioned case report was approved by the
Ethics Committee for Clinical Research of Shandong Qianfoshan Hospital
concerning the publication of this manuscript and any accompanying
Written informed consent was obtained from the patient for publication of
this case report and any accompanying images.
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