Lipoleiomyosarcoma Presenting as Massive Retroperitoneal Mass: An Unusual Soft Tissue Tumor of Abdomen and its Review of Literature

Abstract

Lipoleiomyosarcoma is a malignant tumor of both mesenchymal and smooth muscle origin. Lipoleiomyosarcoma is a very rare type of retroperitoneal sarcoma, which by itself is a rare type of soft tissue sarcoma. Lipoleiomyosarcoma is a very rare subtype of liposarcoma, which is the most common type of retroperitoneal sarcoma. To our best review of available literature, this was the first case of lipoleiomyosarcoma presenting as a massive retroperitoneal mass of size 50 × 50 × 30 cm, managed with multi-visceral R0 resection. The computed tomography of the abdomen showed a massive fat density lesion with internal soft density lesions and internal calcifications. Multivisceral resection was planned and executed and achieved R0 resection. We suggest that lipoleiomyosarcoma should be included in differential diagnosis of retroperitoneal tumors, and multi-visceral R0 resection should be considered as an option for lipoleiomyosarcoma, as these tumors have very good prognosis with R0 resection.

Introduction

Lipoleiomyosarcoma is a malignant tumor of both mesenchymal and smooth muscle origin [1]. Retroperitoneal sarcomas are rare tumors, which account for around 15% of all soft tissue sarcomas [2]. Lipoleiomyosarcoma is a very rare neoplasm with very few case reports and one study reported in history [1, 3, 4]. We present a case report of a case of massive retroperitoneal sarcoma which was unusually very large, of size 50 cm, which was managed surgically.

Case Report

A 35-year-old male presented with complaints of abdominal distension and vague abdominal pain for the past 3 months. He had no altered bladder or bowel habits. A clinical image of the patient with abdominal distension is shown in Fig. 1.

Fig. 1.

Clinical image of the patient with abdominal distension

Contrast enhanced computed tomography (CECT) of the abdomen was done and found to have 31 × 38 × 39 cm fat density lesion with internal soft density lesions and internal calcification. Lesion abuts the pancreas, abdominal wall, aorta, inferior vena cava, psoas muscle, and urinary bladder as shown in Fig. 2.

Fig. 2.

Contrast Enhanced Computed Tomography abdomen showing massive retroperitoneal mass abutting pancreas, abdominal wall, aorta, inferior vena cava, psoas muscle, and urinary bladder

Ultrasonography-guided biopsy of the abdominal mass was done, and the report came negative for malignancy. As the imaging features suggest high suspicion of malignancy, surgery was planned. According to NCCN guidelines, if imaging is suggestive of liposarcoma, surgery can be proceeded, even with a negative biopsy report.

Intraoperatively, a mass of size 50 × 50 × 30 cm was found and was adherent to the left kidney and descending colon. Mass excision in toto with left kidney, left adrenal gland, and descending colon segmental resection was done. Intraoperative image and postoperative specimen are shown in Fig. 3.

Fig. 3.

A) post-operative specimen with weight of 23 kg is shown in the picture. B) intra-operative image of the mass to be resected C) post operative specimen of multivisceral resection for lipoleiomyosarcoma. Mass excised in toto with left kidney, left adrenal gland and a small segment of descending colon

The postoperative biopsy report was suggestive of well-differentiated liposarcoma. The immunohistochemistry report came as lipoleiomyosarcoma. The histological images are shown in Fig. 4.

Fig. 4.

Histopathological image of lipoleiomyosarcoma. White arrow shows leiomyosarcomatous component. Black arrow shows lipomatous component of the tumor

The postoperative period was uneventful. The patient recovered well and was discharged on the 7th postoperative day. The patient was followed up for one and a half years till now, and a recent computed CECT abdomen showed no evidence of recurrence.

Discussion

Lipoleiomyosarcoma is a rare malignant neoplasm; its first case was reported by Evans in 1990 [5]. Since then, very few case reports and one clinicopathological study have been published in the literature as shown in Table 1.

Table 1.

Case reports and clinicopathological studies published in the literature

S. no	Reference	Number of cases	Location (number of cases)
1	Evans(1990) [5]	3	Scrotum (1), mediastinum (1), abdomen (1)
2	Talini et al. (1993) [9]	2	Retroperitoneum (2)
3	Suster et al. (1993) [10]	2	Scrotum (1), retroperitoneum (1)
4	Evans et al.(1994) [11]	1	Abdomen (1)
5	Gomez- Roman et al. (1997) [12]	1	Mediastinum (1)
6	Andrew L Folpe et al. (2002) [1]	9	Popliteal fossa (1), mediastinum (1), retroperitoneum (2), lung (1), abdomen (1), scrotum (1), inguinal (2)
7	Jha et al. (2007) [13]	1	Uterus (1)
8	Hwang et al. (2010) [14]	1	Uterus (1)
9	Lee et al. (2012) [15]	2	Uterus(2)
10	Veronique Drapeau-Zgoralski (2017) [16]	1	Uterus (1)
11	J-J Tong (2018) [3]	1	Posterior mediastinum (1)
12	Wasim Firoz Khan (2019) [4]	1	Spermatic cord (1)
13	Present study	1	Retroperitoneal (1)

Malignant lesions are four times more common than benign lesions in the retroperitoneum, unlike elsewhere in the body [6]. Nearly more than 50% of retroperitoneal tumors are more than 20 cm at presentation [7]. Liposarcoma and leiomyosarcoma are the most common types of retroperitoneal sarcoma [8]. Liposarcoma has three biological groups: atypical lipomatous tumor/well-differentiated and dedifferentiated, myxoid round cell, and the pleomorphic type. The most common is the well-differentiated and dedifferentiated category [8]. Lipoleiomyosarcoma is a rare tumor that is found to have smooth muscle components within liposarcoma. It seems that the smooth muscle component originates from the vessels in the tumor and its typically low grade, and the behavior of the tumor is very similar to well-differentiated liposarcoma [1].

These tumors histologically have well-differentiated smooth muscle with no nuclear atypia [1]. According to the NCCN guidelines, Soft Tissue Sarcoma, Version 1.2023, in these types of tumors, R0 resection is the mainstay of treatment. A preoperative biopsy is not mandatory unless neoadjuvant therapy is planned.

The other important differential diagnosis for lipoleiomyosarcoma is dedifferentiated liposarcoma which has a leiomyosarcoma component in the dedifferentiated part of liposarcoma. These are high-grade sarcoma with a bad prognosis [1].

L Folpe et al. presented in 2002 a retrospective case series of nine cases of lipoleiomyosarcoma and concluded that these tumors also have significant local recurrence risk and have advised R0 resection as the mainstay of treatment [1]. A total of only around 25 cases were reported in the literature as shown in Table 1.

We present this case, in which we did multi-visceral R0 resection and managed this rare case of lipoleiomyosarcoma of size 50 × 50 × 30 cm, which was a great surgical adventure and test for a surgeon’s skill.

Conclusion

A multi-visceral resection is a feasible option that can be tried by doing exploratory laparotomy for patients who have a mass with multi-organ involvement. Lipoleiomyosarcoma has a good prognosis with R0 resection, even if it is done by doing a multi-visceral resection.

Declarations

Competing Interests

The authors declare no competing interests.

Patient ‘s Consent Statement

Patient’s identity is not exposed in this article, and permission was taken from the patient regarding publication. Institute committee clearance for publication was obtained.