Intraperitoneal Rupture of a Synovial Sarcoma of the Kidney
Case Review Intraperitoneal Rupture of a Synovial Sarcoma of the Kidney Andrew Stamm, MD,1 Neal Conti, MD,1 Semra Olgac, MD,1 John Paul Flores, MD,1 Michael J. Wagner, MD,2 Paul Kozlowski, MD1 1Virginia Mason Medical Center, Seattle, WA; 2University of Washington Medical Center, Seattle, WA Primary renal synovial sarcoma is an aggressive, extremely rare disease. Nearly all reported cases are characterized by SYT-SSX gene translocation (X;18)(p11;q11). We describe the case of a 43-year-old woman who presented with an intraperitoneal rupture of this rare sarcoma followed by a right radical nephrectomy. Follow-up imaging 1 month after surgery revealed peritoneal carcinomatosis. She began systemic chemotherapy with doxorubicin and dacarbazine, progressed after 3 months, and is currently receiving single-agent ifosfamide. Only one instance of intraperitoneal rupture has been reported previously. This case report contributes to the characterization of this rare disease. [Rev Urol. 2019;21(2/3):141–143] © 2019 MedReviews®, LLC KEY WORDS Renal synovial sarcoma • Kidney cancer • Oncology P rimary renal synovial sarcoma is an aggressive and extremely rare disease entity. It was first described by Argani and colleagues in 2000,1 and fewer than 70 cases have been reported internationally.2 Tumors are genetically characterized by the SYT-SSX gene translocation (X;18)(p11;q11), found in nearly all reported cases.3 Patients are typically young (mean age, 35-40 years) and nearly all present symptomatically with pain or hematuria.2 Tumor appearance on imaging is characteristically large, heterogeneous, cystic, and often associated with calcifications and subcapsular hematoma.4 To our knowledge, only one prior case of intraperitoneal rupture has been described.1 Case Report A 43-year-old, previously healthy woman presented to the hospital with 1 month of worsening right flank pain. On computed tomography, she was found to Vol. 21 No. 2/3 • 2019 • Reviews in Urology • 141 Kidney Cancer continued with doxorubicin and dacarbazine. After 3 months on this regimen she progressed and is currently receiving single-agent ifosfamide. Discussion Figure 1. Axial and coronal computed tomography demonstrating intraperitoneal rupture of this complex heterogeneous right renal mass. have an 11 3 17 3 15–cm complex, heterogeneous, enhancing, cystic mass of the right kidney with intraperitoneal rupture (Figure 1). She was operated on semi-urgently for right radical nephrectomy. The mass appeared disrupted and renal fascial planes were obliterated with significant intraperitoneal hemorrhage. Histopathology revealed an invasive renal tumor predominantly comprised of spindle cells [Figure 2(A)] with small foci of necrosis [Figure 2(B)] and large areas of cystic change. Dilated tubular structures within the tumor, with cuboidal epithelium and hobnailing of the nuclei were noted, likely representative of entrapped dilated native tubules [Figure 2(C)]. Focally, there were up to 22 mitoses per 10 high-power fields. Tumor staining was positive for B-cell lymphoma/leukemia-2gene (bcl2) [Figure 2(D)] and vimentin. A smaller number of cells were also positive for epithelial membrane antigen (EMA), estrogen receptor (ER), and cluster of differentiation 10 (CD10). Tumor staining was negative for cytokeratin AE1/AE3, desmin, cluster of differentiation 31 (CD31), human melanoma black (HMB45), melan-A protein, and cluster of differentiation 34 (CD34). Fluorescent in situ hybridization (FISH) was positive for SYT-SSX rearrangement, confirming primary synovial sarcoma of the kidney as the diagnosis. The patient’s pain resolved postoperatively. However, follow-up imaging 1 month later was concerning for possible peritoneal carcinomatosis. The patient was referred to a sarcoma specialty center for further management, where she began systemic chemotherapy Synovial sarcoma of the kidney is an aggressive tumor characterized by a specific genetic translocation, SYT-SSX, (X;18)(p11;q11). Fewer than 70 cases have been reported to date,2 including patients as young as 17 years.5 All of these cases presented symptomatically, other than one incidental case discovered during pregnancy.6 On imaging, these tumors are characteristically large, well circumscribed, heterogeneously enhancing, multi-cystic masses that may contain calcifications.7 Cysts are due to entrapped, dilated renal tubules. Radiographically, cysts appear smooth walled with enhancing soft-tissue components, in contrast to the septa and mural nodules often seen in renal cell carcinoma. Further, massive, heterogeneous, soft-tissue A B C D Figure 2. (A) Tumor is predominantly comprised of spindle cells. (B) Rare foci of epithelioid cells. (C) Dilated tubular structures with cuboidal epithelium and hobnailing of nuclei. (D) Tumor cells show positivity for Bcl-2, negative for desmin, CD31, and CD34. 142 • Vol. 21 No. 2/3 • 2019 • Reviews in Urology Kidney Cancer enhanced, solid components of the cysts are typical of synovial sarcoma and rarely seen in renal cell carcinoma.7 Although imaging findings are distinct, genetic and histological analyses are the essential components for diagnosis. Histologically, synovial sarcoma is characterized by infiltrative spindle cells that are destructive to the renal parenchyma. Often, “trapped” intratumor cysts are seen, lined by hob-nailed epithelial cells (Figure 2). On immunohistochemistry, transducin-like enhancer protein 1 (TLE1) and bcl2 are characteristically positive, whereas cluster of differentiation 24 (CD24) and S100 protein are typically negative.3 Identification of the SYT-SSX gene translocation is specific for diagnosis of synovial sarcoma. It is likely that the lack of genetic evaluation has in some cases led to underdiagnosis of this disease.8 For prognosis, the stage at diagnosis appears to be the most important contributing factor. Median overall survival is 48 months but is only 6 months in cases with metastases at presentation.2 The mainstay of treatment is radical surgical excision including lymphadenectomy. However, some patients may benefit from neoadjuvant chemotherapy and in these cases a biopsy, especially if performed at a multidisciplinary sarcoma center, may be helpful.9 The role of adjuvant chemotherapy has not been well defined but may be considered for patients at high risk of metastases. For metastatic disease, patients are generally given doxorubicin-based treatment. The addition of ifosfamide to this chemotherapeutic regimen has been shown to increase the effectiveness of doxorubicin but concerns about nephrotoxicity must be considered.10 Synovial sarcoma of the kidney is a genetically characterized malignancy that usually presents symptomatically and requires radical surgical excision. Cyst rupture and subcapsular hematoma are commonly described, possibly contributing to the high rate of recurrence (36%).2 Only one instance of intraperitoneal rupture has been reported prior to the present case. Understanding of the presentation, histology, treatment, and outcomes is critical to advancing understanding of this rare disease. References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Argani P, Faria PA, Epstein JI, et al. Primary renal synovial sarcoma: molecular and morphologic delineation of an entity previously included among embryonal sarcomas of the kidney. Am J Surg Pathol. 2000;24:1087-1096. Iacovelli R, Altavilla A, Ciardi A, et al. 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