Indian Journal of Pathology and Microbiology

: 2023  |  Volume : 66  |  Issue : 2  |  Page : 356--359

Peritoneal sarcomatosis due to undifferentiated pleomorphic sarcoma: A case report and review of the literature

Nilgun Sogutcu1, Seyhmus Kavak2, Serdar Gumus3,  
1 Department of Pathology, Gazi Yasargil Research and Training Hospital, University of Health Sciences, Diyarbakir, Turkey
2 Department of Radiology, Gazi Yasargil Research and Training Hospital, University of Health Sciences, Diyarbakir, Turkey
3 Department of General Surgery and Surgical Oncology, Faculty of Medicine, Cukurova University, Adana, Turkey

Correspondence Address:
Serdar Gumus
Department of General Surgery and Surgical Oncology, Cukurova University, Saricam, Adana - 01330


Undifferentiated pleomorphic sarcoma (UPS), which was previously known as malignant fibrous histiocytoma (MFH), rarely presents in the abdomen, and sarcomatosis due to UPS has not yet been reported in the literature. Here, we present a 62-year-old man who had abdominal sarcomatosis due to UPS with a poor prognosis.

How to cite this article:
Sogutcu N, Kavak S, Gumus S. Peritoneal sarcomatosis due to undifferentiated pleomorphic sarcoma: A case report and review of the literature.Indian J Pathol Microbiol 2023;66:356-359

How to cite this URL:
Sogutcu N, Kavak S, Gumus S. Peritoneal sarcomatosis due to undifferentiated pleomorphic sarcoma: A case report and review of the literature. Indian J Pathol Microbiol [serial online] 2023 [cited 2023 Sep 25 ];66:356-359
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Malignant fibrous histiocytoma (MFH), which was included in the undifferentiated pleomorphic sarcoma (UPS) group with the classification of soft tissue tumors by the World Health Organization in 2013, first defined as a storiform growth pattern histiocytic tumor by Kauffman in 1961.[1],[2] UPS, considered a type of malignant sarcoma, is usually seen in older patients.[3] It constitutes 28% of all soft tissue sarcomas.[4] The location of the tumor is in the lower (49%) and upper (19%) extremities, followed by 16% in the retroperitoneal and abdominal cavity and 9% in the trunk, respectively.[5]

This case report presents a new case of abdominal UPS with peritoneal metastasis, which is extremely rare and had a poor prognosis; it is characterized by complicated clinical and histopathological diagnoses.

 Case History

A 62-year-old male patient was admitted to the emergency room with severe abdominal pain in February 2018. He had weakness and general condition disorder in his medical history and weight loss over the past few months. Physical examination revealed abdominal swelling. In the laboratory tests, no significant feature was found except leukocytosis and high C-Reactive protein (CRP). Air-fluid levels were found on anterior-posterior abdominal X-ray radiography. An intravenous contrast-enhanced abdominal computed tomography revealed a mass in the pelvic region with lobulated contours, irregularly circumscribed with the bowel loops' localization, accompanied by multiple mesenteric implants located in all quadrants of the abdomen [Figure 1]. An emergency laparotomy was performed, and malignant implants with a bleeding tendency were observed in all small intestine segments and colon. The small intestine segment from 30 cm distal to the trietz to 30 cm proximal to the terminal ileum and the sigmoid colon approximately 15 cm in length and omentum were resected.{Figure 1}

A tumor with a size of 9 × 8 × 6 cm in the small intestine and 5.5 × 2.5 × 1.5 cm in the sigmoid colon was observed macroscopically in the pathological examination. There were also many tumoral implants, the largest of which was 7 × 2.5 × 2.5 cm in the omentum. The cross-sectional tumor surface was grayish-white in color and solid character with focal hemorrhagic areas. In the microscopic examination, an invasive tumor was observed in all small intestine layers from mucosa to serosa [Figure 2]. Cancer in the colon surface was only invasive to serosa and muscularis propria. In the immunohistochemical study, tumor cells were diffuse positive with vimentin and CD68 [Figure 3], but PanCK, S100, SMA, desmin, CD34, HMB45, EMA, and CEA were negative [Figure 4]. The Ki-67 proliferation index was about 60% [Figure 5]. The patient was diagnosed with high-grade UPS with the present pathological findings.{Figure 2}{Figure 3}{Figure 4}{Figure 5}

It was decided to give adjuvant radiotherapy to the patient evaluated in the multidisciplinary tumor council after surgery. The treatment could not be continued due to gastrointestinal bleeding and general condition disorder that developed after radiotherapy. The patient died in April 2018.


Patients with abdominal UPS usually present to the hospital for fever, abdominal pain, palpable mass, diarrhea, blood in the stool, and appetite loss. Nonspecific symptoms may develop in patients due to weight loss and increased intra-abdominal pressure.[5] UPS's preoperative diagnosis is challenging, as there are no specific clinical and radiological findings, and no significant elevation in tumor markers is detected. Therefore, when patients are diagnosed, the tumor size is usually large.[6] In addition to clinical, radiological, and laboratory findings, an accurate evaluation and immunohistochemical study by histopathological criteria are required to diagnose UPS.[3]

UPS is divided into four histological types: storiform-pleomorphic, myxoid, giant cell, and inflammatory.[3] Our cases had histomorphology consisting of spindle-shaped and large histiocyte-like cells with prominent nucleoli arranged in a storiform pattern. Distinct pleomorphic cells were scattered in both our patients.

It has been reported immunohistochemically that UPS usually expresses CD68, vimentin, actin, α-1-antitrypsin, and frequently laminin mRNA.[7] However, neither a reproducible immunophenotype nor any protein expression in the tumor allows for a more specific subclassification.[8]

Intra-abdominal UPS probably has a worse prognosis than those located in the extremity due to late diagnosis. Although the number of reported cases is limited, many investigators consider intra-abdominal UPS as a rare but aggressive tumor.[6] Tumor size is a significant prognostic factor along with grade.[8] Wide surgical resection with negative tumor margins is the preferred primary treatment modality.[8] Metastases occur in the lung (82%), lymph nodes (32%), then bone and liver, respectively.[5] Recent studies suggest that some indicators such as phosphorylation of signal transducer and activator of transcription protein 3 (STAT3), 3'-untranslated region of suppressor of cytokine signaling 3 (SOCS3), MET, and KIT proteins overexpression may be useful prognostic factors for UPS.[9],[10] Another important criterion in the UPS prognosis is the ratio of the myxoid component.[3] The metastatic tendency of myxoid tumors was lower. Therefore, patients with myxoid tumors may not need systemic therapy, whereas patients with nonmyxoid tumors larger than 5 cm are at risk of developing a local recurrence or distance metastases.[3]

The use of adjuvant radiotherapy in treating patients with intraabdominal UPS is controversial, and it is not applied routinely. However, neoadjuvant radiotherapy can be considered successful radical resection in advanced stage retroperitoneal tumors.[3] Adjuvant radiotherapy was given to our patient after evaluating the multidisciplinary tumor council. The treatment was discontinued due to gastrointestinal bleeding and general condition disorder in the patient, and he died in the 4th month of follow-up.

To conclude, UPS is an uncommon tumor and rarely presents with peritoneal sarcomatosis. Diligent evaluation of histopathological features is critical at diagnosis. Also, there are no standard recommendations for therapeutic strategy given these tumors' rarity, and the prognosis is poor.

Declaration of patient consent

The consent form was obtained from the patient at the first admission to the hospital for future studies. The authors certify that they have obtained all appropriate patient consent forms. In the form the patient has given his/her/their consent for his images and other clinical information to be reported in the journal. The patient understand that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


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