 Abstract | | |
A 25-year-old woman had a mass of approximately 65 cm × 33 cm × 102 cm, located in the left paraaortic area on CT scan. It was diagnosed as retroperitoneal malignant neoplasm on imaging. Afterward, open retroperitoneal tumor excision was performed. At laparotomy, the mass was carefully dissected from the ureter, renal artery, and aorta and excised as en-bloc. The pathological result was “myopericytoma.” Histologically, the pathological findings characterized a pericytic neoplasm characterized by a perivascular growth of myoid tumor cells. In addition, there were uniform, oval-shaped cells with eosinophilic cytoplasm arranged in short fascicles around blood vessels. The cytologic atypia and mitoses were absent. There are many different tumors in the retroperitoneal area. Most of these lesions are malign nature. Nevertheless, for each benign and malign neoplasm, the preoperative imaging method is generally similar. This present case showed the significant findings of myopericytoma, a benign pathology located in the retroperitoneal area.
Keywords: Benign retroperitoneal mass, case report, myopericytoma, retroperitoneal mass
How to cite this article:
Ozkent MS, Günler T, Gönen M. A retroperitoneal myopericytoma: The first case located at the retroperitoneal area and not originate from the kidneys. Indian J Pathol Microbiol 2023;66:369-71 |
How to cite this URL:
Ozkent MS, Günler T, Gönen M. A retroperitoneal myopericytoma: The first case located at the retroperitoneal area and not originate from the kidneys. Indian J Pathol Microbiol [serial online] 2023 [cited 2023 Jun 3];66:369-71. Available from: https://www.ijpmonline.org/text.asp?2023/66/2/369/345840 |
| Introduction | |  |
Myopericytoma is rarely seen benign mesenchymal neoplasm. It generally originates from the skin and soft tissue and typically occurs on the distal extremities and trunk.[1] Rarely has reported neck region or visceral organs.[2],[3] Also, it has been reported some cases originated from kidneys.[4],[5]
However, in the literature analysis, there were no cases from the originated retroperitoneal area. In this present study, we aimed to present the first case on the isolated retroperitoneal area.
| Case History | | |
A 25-year-old woman was referred to our clinic with a retroperitoneal mass. The pulmonary lobectomy surgery was performed 18 months ago. The pathological result of this surgery was leiomyomatosis. Afterward, she did not receive additional treatment during the follow-up period. An incidental retroperitoneal mass was detected on contrast-enhanced abdominal computed tomography (CT). It was shown a mass of approximately 65 cm × 33 cm × 102 cm, located in the left paraaortic area on CT scan [Figure 1]. It started from the inferior of the left adrenal gland, close to the left renal artery vein, and extending to the iliac artery. Besides, this mass was containing cystic degeneration and enhancement. It was diagnosed as retroperitoneal malignant neoplasm on imaging. Also, no local invasion or metastasis was seen on CT scan. She had no abdominal symptoms. There was no apparent abnormality on the physical examination findings. Also, all laboratory findings were within normal limits. Open retroperitoneal tumor excision was performed. At laparotomy, the mass was carefully dissected from the ureter, renal artery, and aorta and excised as en-bloc [Figure 2]. The patient was follow-up at the postoperative period without any problems and discharged on the third postoperative day. The patient was followed up for three months, and no tumors recurred or metastasized. | Figure 1: Abdominal CT scan showed a mass of approximately 65 × 33 × 102 cm, located in the left paraaortic area
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The pathological result was “myopericytoma.” The macroscopic evaluation showed an 8.5 cm × 5.5 cm × 3 cm elastic, greyish-brown solid cut surface. Cream-colored areas with bleeding drew attention in the cross-section. Histologically, the pathological findings characterized a pericytic neoplasm characterized by a perivascular growth of myoid tumor cells (HEX100) [Figure 3]a. In addition, there were uniform, oval-shaped cells with eosinophilic cytoplasm arranged in short fascicles around blood vessels. The cytologic atypia and mitoses were absent [Figure 3]b. | Figure 3: (a) The myopericytoma is a pericytic neoplasm characterized by a perivascular growth of myoid tumor cells (HEX100). (b) The presence of uniform, oval-shaped cells with eosinophilic cytoplasm arranged in short fascicles around blood vessels. Cytologic atypia and mitoses were absent (HEX200)
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Immunohistochemical stains revealed diffuse and strong staining of the lesional cells with alpha-smooth muscle actin (SMA) [Figure 4]a and h-caldesmon [Figure 4]b. | Figure 4: Immunohistochemical stains revealed diffuse and strong staining of the lesional cells with SMA (a) and h-caldesmon (b)
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| Discussion | | |
Myopericytomas are mesenchymal neoplasms rarely encountered in visceral sites. They are generally benign neoplasm with an indolent clinical course.[6] However, its immunohistochemical profiles and morphologic features have not been entirely understood due to its rarity.[4] There is no specific radiological imaging finding. Therefore, myopericytomas are usually misdiagnosed.[5] This present study was the first case located at the retroperitoneal area without originated any specific organ. Abdominal CT findings were not specific for the myopericytoma. The preliminary diagnosis of the present case at abdominal CT scan was retroperitoneal sarcoma. However, the pathological result was reported myopericytoma.
The term myopericytoma has been reported initially by Requena et al.[7] for described the cutaneous adult myofibroma. In the following years, Granter et al.[8] has stated the myopericytoma characterized by periluminal concentric multilayering proliferation, bland, ovoid- to spindle-shaped cells at seven cases. However, all these seven tumors have been located in distal extremities and originated the subcutaneous and superficial soft tissue.[8] Afterward, the first myopericytoma report of the kidney was described by Lau et al.[9] Besides, the myopericytomas originated renal and bladder were reported in the following periods.[5],[10],[11] In this present example, the neoplasm was located retroperitoneal area, between the ureter and aorta, without renal origin. It has been closely associated with the renal artery and vein and extends from the adrenal gland to the common iliac artery.
The masses located at the retroperitoneal area are extremely rare. The 80% of retroperitoneal masses are originated mesenchymal, as in our case.[12] In addition, they usually grow insidiously and rarely be symptomatic. Therefore, they may reach a huge size.[12] In this present case, the patient was asymptomatic and had a 10 cm retroperitoneal mass. It is one of the top 3 tumors of the largest size in the literature.[4],[5],[13],[14] The majority of retroperitoneal masses are malignant. Contrary to the other retroperitoneal masses, myopericytomas are usually benign. However, rare cases of malignant myopericytomas have been reported.[15] These malignant myopericytomas have been located on the arm, thigh, neck, and foot.[15] However, all primary renal myopericytomas have been benign.[5] Similar to the other urological myopericitomas, in this present case was benign.
Usually, the first and single treatment of myopericytoma is surgical excision.[5] In light of this finding, we performed the retroperitoneal tumor excision in this case. There was no recurrence or metastasis within the followed-up three months and no need for any additional treatment.
The pathological findings of myopericytoma are commonly seen as the concentric growth of neoplastic cells from prominent vascular spaces. Generally, these neoplasms also contain ovoid, spindled, or round myoid tumor cells with abundant cytoplasm. These cells have eosinophilic cytoplasm and have no nuclear atypia or hyperchromasia. Besides, it has been reported that necrosis was not observed in these neoplasms.[4],[5] Similar to other findings, this present case had a pericytic neoplasm characterized by a perivascular growth of uniform, oval-shaped cells with eosinophilic cytoplasm myoid tumor cells. Also, there was no necrosis or cytologic atypia. These cells were diffusely positive for alpha-smooth muscle actin and h-caldesmon.
This case is the first example in the literature located at the retroperitoneal area without any specific organ. This lesion was compatible with the characteristic pathological findings of myopericytoma. It is following up without the need for additional treatment, except for surgical treatment.
In conclusion, there are many different tumors in the retroperitoneal area. Most of these lesions are malign nature. Nevertheless, for each benign and malign neoplasm, the preoperative imaging method is generally similar. This present case showed the significant findings of myopericytoma, a benign pathology located in the retroperitoneal area.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
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Correspondence Address:
Mehmet Serkan Ozkent
Department of Urology, Konya City Hospital, Akabe Quarter, Adane Cevreyolu Street, Konya - 42020
Turkey
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/ijpm.ijpm_403_21
[Figure 1], [Figure 2], [Figure 3], [Figure 4] |
