CASE REPORT

A Case of Primary Myxoid Malignant Fibrous Histiocytomaof the Pancreas: Clinical, Histopathology,and Immunohistochemistry Findings

Pallav Gupta & Anu Behari & Manoj Jain

Published online: 3 June 2011# Springer Science+Business Media, LLC 2011

Introduction

Malignant fibrous histiocytoma (MFH) had beenregarded as the most common soft tissue sarcoma [1].However, after the introduction of immunohistochemistry(IHC), there has been a significant reduction in the numberof cases characterized as MFH. Presently, the diagnosis ofMFH is reserved only for those soft tissue sarcomas whichdo not show any definitive line of differentiation. Theextremities, retroperitoneum, and trunk are the commonsites of MFH [2]. MFH of the visceral organs like thelung, genitourinary tract, and cardiovascular system hasalso been described. Myxoid MFH (myxofibrosarcoma) ofthe pancreas is extremely rare with only three casesdescribed in world literature till date [3–5]. None of thecases reported earlier describe immunohistochemical find-ings of pancreatic myxoid MFH. Herein, we present apatient with myxoid MFH of the pancreas with clinical,radiological, histopathology, and immunohistochemistryfindings.

Case Report

A 52-year-old male patient presented in December 2010with history of epigastric pain for 4 months. Pain wasprogressively increasing in intensity with radiation to theback. The patient had a history of loss of weight andappetite during this period. There was no history ofhematemesis, hematochezia, fever, or jaundice. The patientwas a non-alcoholic and a non-smoker. There was noicterus or peripheral lymphadenopathy. Ultrasound of theupper abdomen showed a mass involving the body and tailof the pancreas. Abdominal computed tomography (CT)showed an 8×7×6-cm solid cystic mass involving the bodyand tail of the pancreas. The common bile duct and liverwere free of infiltration, and there was no lymph node orvisceral metastasis. The routine hematological laboratoryparameters were within normal limits. The patient under-went distal pancreaticosplenectomy with a provisionaldiagnosis of pancreatic neoplasm. At laparotomy, a tumorwas seen to involve the body and tail of the pancreas. Therewas no evidence of ascites, metastasis to the liver or spleen,and peritoneal/omental deposits. There was no abdominallymphadenopathy, and the superior mesentric vessels werefree of tumor infiltration. The post-operative course wasuneventful, and patient was discharged on the tenth post-operative day.

On gross examination, the specimen measured 8×8×4 cm;the tumor was seen to involve the body and tail of thepancreas. The cut surface of the tumor was largely solid graybrown with myxoid areas (Fig. 1). Microscopic examinationshowed a malignant neoplasm predominantly composed ofmyxoid areas with oval to spindle-shaped cells arranged in

P. Gupta :M. Jain (*)Department of Pathology,Sanjay Gandhi Postgraduate Institute of Medical Sciences,Lucknow, UP 226014, Indiae-mail: mnjjain@yahoo.com

P. Guptae-mail: pallavkmc1@gmail.com

A. BehariDepartment of Gastrosurgery,Sanjay Gandhi Postgraduate Institute of Medical Sciences,Lucknow, UP 226014, Indiae-mail: anubehari@sgpgi.ac.in

J Gastrointest Canc (2012) 43 (Suppl 1):S16–S19DOI 10.1007/s12029-011-9293-x

fascicles interspersed by a curvilinear array of blood vessels(Fig. 2). Foci of microcystic change were also seen. Cellularareas consisting of moderately anisomorphic spindle-shapedcells with bizarre nuclei, multinucleate giant cells, andinflammatory cells were also evident (Fig. 3). Focally,cellular areas had 4–5 mitoses/10 hpf. Any area of tumornecrosis was not identified. On IHC, tumor cells werepositive for vimentin (Fig. 4) and negative for desmin,smooth muscle actin, S-100, CD34, CD 117, EMA, andCEA. Ki-67 was positive in 20–30% of tumor cells. Basedon morphology and IHC, a diagnosis of intermediate-grademyxoid MFH (myxofibrosarcoma) was made. The patientwas stable at the end of 2 months of follow-up.

Discussion

Primary sarcomas of the pancreas are rare and represent lessthan 1% of pancreatic neoplasms [6]. Primary myxoidMFH (myxofibrosarcoma) of the pancreas is even rarer[3–5]. In the present case, a CT scan revealed a solid cystictumor involving the body and tail of the pancreas withoutany visceral or lymph node metastasis or any significantadhesion to the retroperitoneum. The patient underwentdistal pancreatectomy with splenectomy. Based on histopa-thology and IHC, the tumor was characterized as myxoidMFH (myxofibrosarcoma). Till date, only three cases ofmyxoid MFH of the pancreas have been reported in world

Fig. 1 Gross photograph showing the pancreas with a tumor massmeasuring 10×8×4 involving the body and tail of the pancreas.The cut surface of the tumor was largely solid gray brown withmyxoid areas

Fig. 2 Microphotograph showing mildly anisomorphic spindle tostellate cells in a myxoid background with curvilinear array of bloodvessels (H&E, ×200 original magnification)

Fig. 3 Microphotograph showing cellular areas with bizarre andmultinucleate giant cells (H&E, ×200 original magnification)

Fig. 4 Microphotograph showing tumor cells positive for vimentin(IHC, ×200 original magnification)

J Gastrointest Canc (2012) 43 (Suppl 1):S16–S19 S17

literature (Table 1) of which two were located within bodyand tail of the pancreas [3–5].

The cell of origin of MFH is thought to be fromundifferentiated mesenchymal cells. MFH of the pancreasusually occurs after the fourth decade of life with aM/F ratio of2:1. It has a mean diameter of 10.7 cm and has been reportedwith equal frequency in the body or the head of the pancreas.Clinical manifestations described in literature are variable, butupper abdominal symptoms are the most frequent presentation[7]. CT and MRI findings have been described as a large,massive liquescent necrotic mass or multilocular cystic lesion,with calcification or a hypointense area on T2-weightedimages [8]. There is also a great variation in histologicalfeatures of MFH of the pancreas. However, the differenthistological variants do not differ in prognosis [7].

In recent years, the myxoid variant of MFH (myxofi-brosarcoma) has been considered as a distinct sarcomatouslesion. Ultrastructurally, the tumor cells exhibit fibroblasticdifferentiation with prominent secretory activity within amyxoid matrix. On histopathology, myxoid MFH can begraded as low-, intermediate-, and high-grade lesions basedon cellularity, pleomorphism, mitotic activity, and presenceof necrosis. Low-grade lesions display a prominent myxoidmatrix, mild cellular pleomorphism, and occasional mitosis.High-grade lesions show more solid hypercellular areaswith marked cellular pleomorphism, numerous often atyp-ical mitotic figures along with confluent areas of necrosisand hemorrhage. Intermediate-grade lesions are cellular butdo not show pronounced cellular pleomorphism and lackareas of necrosis [9]. Proliferation index, as determined bypercentage of tumor cells displaying Ki-67 positivity, hasbeen demonstrated to have some association with histologicgrade. In low-grade lesions, it varies from 1.63–10.6%; inintermediate-grade lesions, it varies from 8.9–21.9%, and inhigh-grade neoplasms, it varies from 7–34% [9].

Surgery is the mainstay of treatment for myxoid MFH(myxofibrosarcoma). Till date, the role of adjuvant chemo-therapy or radiotherapy is not established for these neo-plasms. Two of the three cases reported earlier underwentleft pancreatectomy with splenectomy whereas one under-went pancreaticoduodenectomy. All the three cases reportedearlier including the present case did not receive any

adjuvant chemotherapy or radiotherapy [3–5]. MyxoidMFH is associated with high rate of local recurrences; therecurrent neoplasms have a tendency to be of higher grade.Local recurrences occurring within a year are associatedwith increased mortality.

IHC in myxoid MFH is positive for vimentin; focalpositivity can also be seen for muscle-specific actin and α-smooth muscle actin; however, these tumors do not showany definite line of differentiation [9, 10]. Histology in ourcase showed predominantly myxoid areas with few cellularareas showing multinucleate tumor giant cells and infre-quent mitosis. IHC showed positivity only for vimentin andnegative staining for other markers. Ki-67 proliferationindex ranged from 20% to 30%.

The pathological differential diagnosis among the pan-creatic neoplasms includes gastrointestinal stromal tumorwhich usually shows a biphasic pattern with epithelial andmesenchymal components and positivity for CD117 andCD34 on IHC. Low-grade myxofibrosarcoma must bedistinguished from myxoid neurofibroma which showsneural cytomorphology, presence of Wagner–Meissnerbodies, and S-100 immunopositivity of tumor cells [9].

The biological behavior of pancreatic MFH is reported tobe similar to retroperitoneal MFH with respect to prognosisand local aggressiveness, the 5-year survival being less than20% [11]. However, long-term follow-up studies withrespect to myxoid MFH of the pancreas are not available.

To conclude, primary myxoid MFH (myxofibrosarcoma)is an extremely rare tumor of the pancreas. This entityshould be considered in the differential diagnosis of thepancreatic mass lesions in middle-aged patients presentingwith solid cystic lesion on radiology. The present casehighlights the clinicopathological, radiological, and immu-nohistochemical profile of myxoid MFH of the pancreas.Long-term follow-up studies are needed to know the exactbiological behavior of these neoplasms.

Conflicts of Interest None.

Funding None.

Table 1 Reported cases of myxoid malignant fibrous histiocytoma of the pancreas

Study Year Age Sex Histology Site Treatment Follow-up

Margueles et al. [3] 1976 22 F Myxoid Head Pancreaticoduodenectomy 17 months, NR

Filippini et al. [4] 1992 50 F Myxoid Body–tail Lt pancreatectomy, splenectomy No follow-up

Liu et al. [5] 1999 27 F Myxoid Body–tail Lt pancreatectomy, splenectomy 6 months, NR

Gupta et al. 2011 52 M Myxoid Body–tail Distal pancreatectomy, splenectomy 2 months, NR

NR no recurrence, Lt left

S18 J Gastrointest Canc (2012) 43 (Suppl 1):S16–S19

References

1. Enjoji M, Hashimoto H. Diagnosis of soft tissue sarcomas. PatholRes Pract. 1984;178:215–26.

2. Weiss SW, Enzinger FM. Malignant fibrous histiocytoma: ananalysis of 200 cases. Cancer. 1978;41:2250–66.

3. Margules RM, Allen RE, Dunphy JE. Pancreatic tumor ofmesenchymal origin presenting as obstructive jaundice. Am J Surg.1976;131:357–9.

4. Filippini A, Lucci S, Berni A, Maggi S, Romani AM, Grilli P, etal. [Malignant fibrous histiocytoma of the pancreas]. G Chir.1992;13:485–8.

5. Liu DM, Jeffrey RB, Mindelzun RE. Malignant fibrous histiocytomapresenting as cystic pancreatic mass. Abdominal Imaging.1999;24:299–300.

6. Cubilla AL, Fitzgerald PJ. Tumors of the exocrine pancreas. In:Atlas of tumor pathology, fascicle 19. Washington, DC: ArmedForces Institute of Pathology, 1984

7. Jarry J, Belleannee G, Laurent C, et al. Primary malignant fibroushistiocytoma of the pancreas: benefit of the multidisciplinaryapproach. Eur J Gastroenterol Hepatol. 2010;22:765–8.

8. Ri-Sheng Y, Jia-WeiW YC, Wen-Hong D, Xiu-Fang X, Li-Rong C.A case of primary malignant fibrous histiocytoma of the pancreas:CT and MRI findings. World Journal of Gastroenterology.2008;14:2942–5.

9. Mentzel T, Calonje E, Wadden C, Camplejohn RS, Beham A,Smith MA, et al. Myxofibrosarcoma: clinicopathologic analysis of75 cases with emphasis on low grade variant. The AmericanJournal of Surgical Pathology. 1996;20:391–405.

10. Merck C, Angervall L, Kindblom LG, Oden A. Myxofibrosarcoma.A malignant soft tissue tumor of fibroblastic-histiocytic origin. Aclinicopathologic and prognostic study of 110 cases using multivar-iate analysis. Acta Pathologica, Microbiologica, et ImmunologicaScandinavica Supplement. 1983;282:1–40.

11. Kearney MM, Soule EH, Ivins JC. Malignant fibrous histiocy-toma: a retrospective study of 167 cases. Cancer. 1980;1980(45):167–78.

J Gastrointest Canc (2012) 43 (Suppl 1):S16–S19 S19