Pancreatic liposarcoma: A case series and literature overview of an extremely rare soft tissue tumor

Abstract

Introduction and importance: Liposarcoma is a subtype of soft tissue sarcoma. It can originate from any adipose tissue in the body. However, the most common sites are deep soft tissues of the lower extremities and retroperitoneum. Liposarcoma arising from the pancreas is extremely rare. It occasionally presents with epigastric pain and abdominal distension, yet, in most cases it is asymptomatic. It can be discovered incidentally on radiological imaging. Complete surgical excision is the only effective cure. Definitive pathological classification can be made after histopathological assessment with additional diagnostic features in biopsy material of the resected tumor. Herein, we present a case series of three consecutive adult patients with pancreatic liposarcoma who were treated surgically to increase our understanding of surgical and pathological aspects of this type of tumor.

Case presentation: The first patient is a 75-year-old female with recurrence of a well differentiated liposarcoma with partial dedifferentiation in the pancreatic head who was managed surgically with pylorus-resecting pancreaticoduodenectomy (PrPD). The second patient is an 80-year-old female with pleomorphic liposarcoma of the pancreatic head who was managed surgically with the same approach. The final patient is a 72-year-old male with primary dedifferentiated liposarcoma and well-differentiated liposarcoma located dorsal to the duodenum, in close contact with the right renal fascia and with ingrowth into the pancreatic head. This patient was managed surgically with PrPD involving right nephrectomy.

Clinical discussion: In this case series, we added three new cases of pancreatic liposarcoma to twenty earlier reported cases in the literature. Complete resection is not the only indicator of recurrence, recurrence can be faster in high grade tumors, such as dedifferentiated liposarcoma and pleomorphic liposarcoma. None of the patients in our study underwent (neo)-adjuvant chemo-radiotherapy.

Conclusion: Surgical resection remains the curative treatment of choice for pancreatic liposarcoma. Pancreatoduodenectomy is considered safe, and it should only be performed when in line with patient physical fitness and preferences. Personalized exercise program to improve fitness is recommended in patients with low aerobic fitness.

Keywords: Aerobic fitness; Complications; Pancreas; Pancreatic liposarcoma; Pancreatoduodenectomy.

Fig. 1

Portal venous phase abdominal CT in axial (A, C) and coronal (B) direction, showing a mass (between arrowheads) in the pancreatic head with a maximum diameter of 37 mm and heterogeneous enhancement. Also, the pancreatic duct proximal to the mass is dilated (arrow in image B). (C) showing the mass (between arrowheads) in the pancreatic head with a maximum diameter of 43 mm and heterogeneous enhancement. A stent in the common bile duct is present (arrow).

Fig. 2

Histopathological findings in patient 1. (A) resected pancreatic liposarcoma with permeative growth in the pre-existing pancreas (arrowhead = liposarcoma; double arrowhead = pre-existing pancreatic tissue. (B—C) Hematoxylin-eosin staining showing liposarcoma with lipoblast and pleomorphic spindle cells (arrowhead) with permeative growth into pancreatic tissue (double arrowhead) (D) Positive MDM2 nuclear immunostaining in tumor cells indicative for MDM2 amplification. These findings are consistent with dedifferentiated liposarcoma (DDLPS) and well-differentiated liposarcoma (WDLPS).

Fig. 3

Abdominal MRI in axial (A-E) and coronal (F) direction. A mass in the pancreatic head (arrowheads) with a maximum diameter of 49 mm is observed, with a heterogeneous hyperintense signal intensity on T2 weighted imaging (A), and clear diffusion restriction (B and C), as well as a heterogeneous enhancement pattern in the late arterial (D) and portal venous phase (E and F).

Fig. 4

(A) Portal venous phase abdominal CT in axial direction, showing a mass (between arrowheads) in the pancreatic head with a maximum diameter of 57 mm and heterogeneous enhancement. (B) Contrast-enhanced abdominal MRI in axial direction in the portal venous phase, showing several enhancing nodular lesions (arrowheads) diffusely distributed in the liver, suspicious for liver metastases.

Fig. 5

Histopathological findings in patient 2. (A) resected pancreatic liposarcoma with a diameter of 62 mm (Arrowhead = liposarcoma; double arrowhead = normal pancreatic tissue) (B—C) Hematoxylin-eosin staining shows pleomorphic lipoblasts (arrowhead). (D) No expression of MDM2 therefore well- differentiated and dedifferentiated liposarcomas were ruled out.

Fig. 6

Portal venous phase abdominal CT in axial direction, showing a mass (between arrowheads in A) in the proximal duodenum with a maximum diameter of 56 mm and slight enhancement. Besides, two nodular lesions at the anterior and medial fascias of the right kidney are present (arrows in A and B).

Fig. 7

Abdominal MRI in axial (A-E) and coronal (F) direction. A mass in the proximal duodenum (arrowheads) is visible, with only slight heterogeneous enhancement in the late arterial (A) and portal venous phase (B and F), heterogeneous slightly hyperintense signal intensity on T2 weighted imaging (C), and clear diffusion restriction (D and E). The lesion extends into the fatty tissue surrounding the duodenum as well as in the pancreaticoduodenal groove (arrow in F).

Fig. 8

Histopathological findings in patient 3. (A) resected pancreatic liposarcoma with a diameter of 95 mm. (B) Hematoxylin-eosin staining shows spindle-shaped tumor cells (left upper part) infiltrating pre-existing pancreatic glandular tissue (right lower part). (C) Fibrous septae with atypical hyperchromatic spindle cells surrounded by abundant lipogenic component with lipoblasts (D) The tumor cells showed strong nuclear MDM2 staining indicative for MDM2 amplification. These findings are diagnostic for dedifferentiated liposarcoma (DDLPS) and well-differentiated liposarcoma (WDLPS).