Primary Leiomyosarcoma of the Pancreas-a Case Report and a Comprehensive Review

Abstract

Purpose: Primary mesenchymal tumors of the pancreas are rare, with leiomyosarcomas the most encountered entities among the pancreatic sarcomas. With few exceptions, single case reports published over the last six decades constitute the entire scientific literature on this topic. Thus, evidence regarding clinical decision-making is scant.

Methods: Based on a case report and an extensive literature search in PubMed, we discuss the clinical aspects and current management of this rare malignancy.

Results: We identified only two papers with more than a single case presentation; these institutional patient series were limited to five and nine patients. Additionally, a few papers sought to summarize the individual case reports published in the English and/or Chinese language. The clinical presentation is rather non-specific. Moreover, modern imaging modalities are insufficiently accurate to diagnose leiomyosarcoma of the pancreas. Treatment goals include a complete resection with free margins. Proper morphologic examination using immunohistochemistry and the application of a grading system are clinically important for prognostication. The efficacy of adjuvant treatments has not been established.

Conclusion: Primary pancreatic leiomyosarcoma is extremely rare, and the scientific literature is primarily based on single case reports. Conclusions on management and prognosis should be drawn with caution. A multidisciplinary team consultation is warranted to discuss a thorough individual treatment plan based on the available scientific literature, despite its low evidence level.

Keywords: Leiomyosarcoma; Mesenchymal tumor; Pancreas; Review.

Fig. 1

Abdominal computed tomography (CT) shows a 15 × 12-mm tumor (white arrow), which is heterogeneously enhanced by contrast media

Fig. 2

Magnetic resonance imaging (T1 sequence) shows the same lesion identified by CT as a 17 × 14-mm heterogeneously enhanced lesion (white arrows) of the pancreatic tail

Fig. 3

a CT of the pancreas with intravenous contrast in the arterial phase (red arrows) shows a 17 × 15-mm tumor with heterogeneous contrast enhancement. b CT of the pancreas in the venous phase shows the tumor (blue arrows) in the pancreatic tail

Fig. 4

a HE ×20 magnification. Lumen of the intrapancreatic venous vessel with the tumor (T) infiltrating the pancreatic tissue (Pa). b Positive staining with actin HHF35. White arrows indicate smooth muscle in the vessel wall. Black arrows indicate the spindle cell proliferation as positive for muscle-specific actin, which is consistent with a leiomyosarcoma

Fig. 5

Discernibly atypical tumor cells (white arrows) with positive staining for desmin, a relatively specific marker for muscle differentiation (magnification ×600)

Fig. 6

a Discernibly atypical sarcoma cells (black arrows), some of which are pleomorphic and show abnormal nuclei, infiltrating the pancreatic soft tissue (magnification ×200). b Normal acinar pancreatic parenchyma (red arrows) with atypical sarcoma cells infiltrating the pancreatic tissue (black arrows) (magnification ×400)