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Low-grade fibromyxoid sarcoma metastatic to the prostate
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Annals of Diagnostic Pathology 15 (2011) 64 – 68
Low-grade fibromyxoid sarcoma metastatic to the prostate Dilek Ertoy Baydar, MDa,⁎, Fazil Tuncay Aki, MDb a
Department of Pathology, Hacettepe University Hospital, 06100 Ankara, Turkey b Department of Urology, Hacettepe University Hospital, 06100 Ankara, Turkey
Abstract
Keywords:
Spindle cell tumors of the prostate are rare and mostly primary. We report a case of retroperitoneal sarcoma, which is a low-grade fibromyxoid sarcoma involving the prostate secondarily by metastasis. The patient was a 44-year-old man who presented with progressing abdominal pain. Computed tomography showed a large retroperitoneal mass. The patient underwent surgical resection. Intraoperatively, a second smaller mass was identified in the pelvis and was left untouched. The resected retroperitoneal specimen and prostate transrectal needle biopsies taken afterward showed the same mesenchymal tumor. Radical cystoprostatectomy was performed. Metatatic tumor involving the prostate, bilateral seminal vesicles, and base of the urinary bladder was found. Microscopic examination revealed typical histomorphologic features of low-grade fibromyxoid sarcoma. The patient is without evidence of disease 3 years postoperatively. This case is the first documentation of metastatic sarcoma to the prostate and expands the list of malignant mesenchymal neoplasms that may involve this organ. © 2011 Elsevier Inc. All rights reserved. Prostate; Sarcoma; Metastasis; Low-grade fibromyxoid sarcoma
1. Introduction Secondary involvement of the prostate by malignant neoplasms most frequently results from direct invasion of carcinomas from contagious organs, mainly the urinary bladder and rectum. Spread from distant organs can also occur, but very rarely. Metastases from the lung, gastrointestinal tract, kidney, testis, malignant melanoma, and endocrine malignancies to the prostate have been previously reported [1,2]. The lung is the most common primary organ. However, these are mainly epithelial tumors, and no metastatic sarcoma to the prostate and seminal vesicles have been described until now. This explains why metastatic sarcomas are not typically included in the differential diagnosis of spindle cell tumors of the prostate. Unawareness of this prospect can result in
⁎ Corresponding author. Tel.: +90 3123051555/170; fax: +90 3124260869. E-mail addresses: [email protected], [email protected] (D.E. Baydar). 1092-9134/$ – see front matter © 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.anndiagpath.2010.01.001
clinical and even pathologic misinterpretation as primary prostatic lesions. However, their recognition is critical because of their possibly unique clinical management. We report the first case of a malignant mesenchymal tumor, which is a low-grade fibromyxoid sarcoma (LGFMS), metastasizing to prostate.
2. Case report A 44-year-old white man with insignificant medical history presented to his primary care physician for abdominal pain that had been progressively worsening during the course of several months. The computed tomography (CT) scan identified a 15 × 12 × 8 cm mass in the retroperitoneum. He underwent an open surgery for the resection at an outside center. During the operation, the surgeon removed the retroperitoneal mass, but noted a second tumoral lesion in the pelvis, to which, without the patient's permission, he did not touch. After histopathologic evaluation, the patient was referred to our hospital with the diagnosis of retroperitoneal malignant mesenchymal tumor.
D.E. Baydar, F.T. Aki / Annals of Diagnostic Pathology 15 (2011) 64–68
65
Fig. 1. Radical cystoprostatectomy. A large mass located in the region of the prostate without undefinable borders in-between.
Fig. 3. Fibrous and myxoid zones with sharp transition and minimal cytologic atypia.
On digital rectal examination, we found the prostate to be enlarged and stony hard. CT scan showed a large tumoral prostate with the impression of involvement of the posterior
bladder wall. Prostate transrectal needle biopsies were taken and sent to our pathology department together with H&E slides of the retroperitoneal mass obtained from the first
Fig. 2. Micrographs showing various microscopic features of the tumor, characteristic of a LGFMS. (A) Alternating dense collagenous and loose areas. (B) Arteriol-like small vasculature. (C) Curvilinear blood vessels. (D) Hyalinizing collagen rosette-like area, poorly formed. (E) Swirling pattern.
66
D.E. Baydar, F.T. Aki / Annals of Diagnostic Pathology 15 (2011) 64–68
Fig. 4. Tumor involves the outer zone of prostate (A and B) and muscularis propria of urinary bladder (C).
center. All 10 cores of needle biopsies showed a spindle cell tumor in the same morphology of with the retroperitoneal lesion. A radical cystoprostatectomy was performed. 2.1. Pathology A mass, 12 × 9 × 5 cm in size, was seen at the low posterior part of the specimen (Fig. 1). It was a solid white lesion with intermingled areas of yellow fat. Its borders could not be distinguished from the prostate and seminal vesicles. Microscopically, the tumor was composed of sweeping bands of heavily collagenized, moderately cellular zones and alternating hypocellular myxoid nodules with abrupt transition in-between (Figs. 2 and 3). In dense areas, short fascicular and whorling growth patterns were present. A large area of hyalinizing collagen was seen at a single location. Neoplastic cells were bland-looking uniform spindle cells without significant atypia. The vasculature exhibited 2 patterns: both arcades of small vessels and arteriole-sized vessels with concentric perivascular cuffs of slender spindle cells. Mitotic rate was very low (b1/20 hpf). Necrosis was not found. The tumor infiltrated periphery of the prostate posteriorly and laterally, seminal vesicles, and deep muscularis propria of the base of urinary bladder (Figs. 4 and 5). It extended to the posterior surgical margins. On the immunohistochemical studies, neoplastic cells expressed vimentin and CD34 diffusely (Fig. 6); they were
negative for S-100, desmin, smooth muscle actin, bcl2, CD117, estrogen receptor (ER), progesterone receptor (PR), pan-cytokeratin, and epithelial membrane antigen. Ki-67 proliferative index was below 1%. The pathologic diagnosis was LGFMS, and it was thought to be metastatic from the primary retroperitoneal tumor.
Fig. 5. Tongues of the myxoid neoplasm infiltrating seminal vesicle.
D.E. Baydar, F.T. Aki / Annals of Diagnostic Pathology 15 (2011) 64–68
67
Fig. 6. Immunohistochemical profile of the tumor: negative for S-100 (A) and smooth muscle actin (B), positive for CD34 (C).
The patient received pelvic radiotherapy. He has been free of disease for 3-year follow-up.
3. Discussion Spindle cell lesions of the adult prostate are infrequent and provide a diagnostic challenge to pathologist. Most prostatic mesenchymal tumors are specialized prostatic stromal tumors (stromal sarcomas and stromal tumors of uncertain malignant potential), smooth muscle tumors, and, on rare occasion, solitary fibrous tumors, inflammatory myofibroblastic tumors, and nerve sheath tumors [3,4]. Gastrointestinal stromal tumors may also be sampled on prostate needle biopsy when the tumor is located between the rectum and prostate [5]. Sarcomatoid carcinoma of the prostate is another rare type of cancer that exhibits spindle cell morphology. Our case is an example that metastatic lesions must also be included in the differential diagnosis of the spindle cell tumors of the prostate. Having been informed about the retroperitoneal mass of the patient that was previously removed, we could manage to reach the accurate diagnosis on prostate needle biopsies, which otherwise would be very cumbersome. The prostate very rarely receives metastatic deposits from distant organs. Sarcomas generally use hematogenous as a way for distant spread, and the most common site is the lung.
There are several reports in the literature showing the potency of sarcomas for “seeding,” which usually occurs through the needle tracts or at the laparoscopic portsites [6,7]. Seeding by gravity seems to be one possible way of metastasis to the prostate in our case, since that the primary tumor is retroperitoneal. LGFMS was first described by Evans in 1987 [8]. It is a rare mesenchymal tumor that affects both men and women equally, and typically involves the deep soft tissues of the proximal extremities and trunk (mostly in young to middle-aged adults, even though it can be seen at any age). The retroperitoneum and abdominal cavity are distinctly unusual locations but have been reported [9,10]. The tumor in our case shows the morphologic characteristics of LGFMS, noted by a proliferation of fibroblastic spindle cells in a whorled pattern with sharply delineated fibrous and myxoid areas without significant cellular pleomorphism and mitosis. Although described as paradoxically aggressive neoplasm in the first reports, recent series have stated better prognosis with recurrences, metastases, and death from disease in only 9%, 6%, and 2% of patients, respectively [9]. LGFMS may metastasize many years after initial diagnosis, and indefinite clinical follow-up is mandatory for patients with this disease. Immunohistochemistry supports the fibroblastic nature of the LGFMS, and can be useful in the diagnosis of this disease to exclude other entities that may enter into the
68
D.E. Baydar, F.T. Aki / Annals of Diagnostic Pathology 15 (2011) 64–68
differential. Vimentin is the only positive marker in most LGFMSs. In our case, the tumor also expressed CD34 diffusely. CD34 immunostaining is known to be present in specialized stromal tumors of the prostate, solitary fibrous tumors, and gastrointestinal stromal tumors as well. These entities can arise in the prostate or in adjacent organs and were considered in our differential diagnosis. However, the typical morphology, lack of sex hormone receptors, and CD117 negativity, in addition to the clinical history, let us designate the lesion as metastatic LGFMS. LGFMSs bear either the t(7,16) (q32-34;p11) or t(11,16) (p11;p11) translocations, resulting in FUS-CREB3L2 or FUSCREB3L1 fusions, respectively [11]. Molecular genetic or cytogenetic analyses can be used as auxiliary diagnostic tools if needed. In conclusion, metastatic sarcomas to the prostate can occur and may bear a resemblance to a primary prostatic neoplasm. One should remember to review the complete medical history of the patient and exclude secondary involvement of the organ by metastasis before diagnosing a rare primary spindle cell tumor on a prostate biopsy.
Acknowledgment We present our special thanks to Dr Jonathan I. Epstein and Dr Elizabeth Montgomery from the Department of Pathology, The Johns Hopkins Hospital. Both experts reviewed our case and concurred with the diagnosis.
References [1] Bates AW, Baithun SI. Secondary solid neoplasms of the prostate: a clinico-pathological series of 51 cases. Virchows Arch 2002;440 (4):392-6. [2] Zein TA, Huben R, Lane W, Pontes JE, Englander LS. Secondary tumors of the prostate. J Urol 1985;133(4):615-6. [3] Gaudin PB, Rosai J, Epstein JI. Sarcomas and related proliferative lesions of specialized prostatic stroma: a clinicopathologic study of 22 cases. Am J Surg Pathol 1998;22:148-62. [4] Herawi M, Epstein JI. Specialized stromal tumors of the prostate: a clinicopathologic study of 50 cases. Am J Surg Pathol 2006;30(6):694-704. [5] Herawi M, Montgomery EA, Epstein JI. Gastrointestinal stromal tumors (GISTs) on prostate needle biopsy: a clinicopathologic study of 8 cases. Am J Surg Pathol 2006;30(11):1389-95. [6] Hidai H, Sakuramoto T, Miura T, et al. Needle tract seeding following puncture of retroperitoneal liposarcoma. Eur Urol 1983;9(6):368-9. [7] Clark MA, Thomas JM. Portsite recurrence after laparoscopy for staging of retroperitoneal sarcoma. Surg Laparosc Endosc Percutan Tech 2003;13(4):290-1. [8] Evans HL. Low-grade fibromyxoid sarcoma. A report of two metastasizing neoplasms having a deceptively benign appearance. Am J Clin Pathol 1987;88:615-9. [9] Folpe AL, Lane KL, Paull G, et al. Low-grade fibromyxoid sarcoma and hyalinizing spindle cell tumor with giant rosettes: a clinicopathologic study of 73 cases supporting their identity and assessing the impact of high-grade areas. Am J Surg Pathol 2000;24:1353-60. [10] Koishi A, Gomibuchi H, Inoue J, et al. Hyalinizing spindle cell tumor with giant rosettes of the omentum. J Obstet Gynaecol Res 2003;29:388-91. [11] Guillou L, Benhattar J, Gengler C, et al. Translocation-positive low-grade fibromyxoid sarcoma: clinicopathologic and molecular analysis of a series expanding the morphologic spectrum and suggesting potential relationship to sclerosing epithelioid fibrosarcoma: a study from the French Sarcoma Group. Am J Surg Pathol 2007;31(9):1387-402.
Annals of Diagnostic Pathology 15 (2011) 64 – 68
Low-grade fibromyxoid sarcoma metastatic to the prostate Dilek Ertoy Baydar, MDa,⁎, Fazil Tuncay Aki, MDb a
Department of Pathology, Hacettepe University Hospital, 06100 Ankara, Turkey b Department of Urology, Hacettepe University Hospital, 06100 Ankara, Turkey
Abstract
Keywords:
Spindle cell tumors of the prostate are rare and mostly primary. We report a case of retroperitoneal sarcoma, which is a low-grade fibromyxoid sarcoma involving the prostate secondarily by metastasis. The patient was a 44-year-old man who presented with progressing abdominal pain. Computed tomography showed a large retroperitoneal mass. The patient underwent surgical resection. Intraoperatively, a second smaller mass was identified in the pelvis and was left untouched. The resected retroperitoneal specimen and prostate transrectal needle biopsies taken afterward showed the same mesenchymal tumor. Radical cystoprostatectomy was performed. Metatatic tumor involving the prostate, bilateral seminal vesicles, and base of the urinary bladder was found. Microscopic examination revealed typical histomorphologic features of low-grade fibromyxoid sarcoma. The patient is without evidence of disease 3 years postoperatively. This case is the first documentation of metastatic sarcoma to the prostate and expands the list of malignant mesenchymal neoplasms that may involve this organ. © 2011 Elsevier Inc. All rights reserved. Prostate; Sarcoma; Metastasis; Low-grade fibromyxoid sarcoma
1. Introduction Secondary involvement of the prostate by malignant neoplasms most frequently results from direct invasion of carcinomas from contagious organs, mainly the urinary bladder and rectum. Spread from distant organs can also occur, but very rarely. Metastases from the lung, gastrointestinal tract, kidney, testis, malignant melanoma, and endocrine malignancies to the prostate have been previously reported [1,2]. The lung is the most common primary organ. However, these are mainly epithelial tumors, and no metastatic sarcoma to the prostate and seminal vesicles have been described until now. This explains why metastatic sarcomas are not typically included in the differential diagnosis of spindle cell tumors of the prostate. Unawareness of this prospect can result in
⁎ Corresponding author. Tel.: +90 3123051555/170; fax: +90 3124260869. E-mail addresses: [email protected], [email protected] (D.E. Baydar). 1092-9134/$ – see front matter © 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.anndiagpath.2010.01.001
clinical and even pathologic misinterpretation as primary prostatic lesions. However, their recognition is critical because of their possibly unique clinical management. We report the first case of a malignant mesenchymal tumor, which is a low-grade fibromyxoid sarcoma (LGFMS), metastasizing to prostate.
2. Case report A 44-year-old white man with insignificant medical history presented to his primary care physician for abdominal pain that had been progressively worsening during the course of several months. The computed tomography (CT) scan identified a 15 × 12 × 8 cm mass in the retroperitoneum. He underwent an open surgery for the resection at an outside center. During the operation, the surgeon removed the retroperitoneal mass, but noted a second tumoral lesion in the pelvis, to which, without the patient's permission, he did not touch. After histopathologic evaluation, the patient was referred to our hospital with the diagnosis of retroperitoneal malignant mesenchymal tumor.
D.E. Baydar, F.T. Aki / Annals of Diagnostic Pathology 15 (2011) 64–68
65
Fig. 1. Radical cystoprostatectomy. A large mass located in the region of the prostate without undefinable borders in-between.
Fig. 3. Fibrous and myxoid zones with sharp transition and minimal cytologic atypia.
On digital rectal examination, we found the prostate to be enlarged and stony hard. CT scan showed a large tumoral prostate with the impression of involvement of the posterior
bladder wall. Prostate transrectal needle biopsies were taken and sent to our pathology department together with H&E slides of the retroperitoneal mass obtained from the first
Fig. 2. Micrographs showing various microscopic features of the tumor, characteristic of a LGFMS. (A) Alternating dense collagenous and loose areas. (B) Arteriol-like small vasculature. (C) Curvilinear blood vessels. (D) Hyalinizing collagen rosette-like area, poorly formed. (E) Swirling pattern.
66
D.E. Baydar, F.T. Aki / Annals of Diagnostic Pathology 15 (2011) 64–68
Fig. 4. Tumor involves the outer zone of prostate (A and B) and muscularis propria of urinary bladder (C).
center. All 10 cores of needle biopsies showed a spindle cell tumor in the same morphology of with the retroperitoneal lesion. A radical cystoprostatectomy was performed. 2.1. Pathology A mass, 12 × 9 × 5 cm in size, was seen at the low posterior part of the specimen (Fig. 1). It was a solid white lesion with intermingled areas of yellow fat. Its borders could not be distinguished from the prostate and seminal vesicles. Microscopically, the tumor was composed of sweeping bands of heavily collagenized, moderately cellular zones and alternating hypocellular myxoid nodules with abrupt transition in-between (Figs. 2 and 3). In dense areas, short fascicular and whorling growth patterns were present. A large area of hyalinizing collagen was seen at a single location. Neoplastic cells were bland-looking uniform spindle cells without significant atypia. The vasculature exhibited 2 patterns: both arcades of small vessels and arteriole-sized vessels with concentric perivascular cuffs of slender spindle cells. Mitotic rate was very low (b1/20 hpf). Necrosis was not found. The tumor infiltrated periphery of the prostate posteriorly and laterally, seminal vesicles, and deep muscularis propria of the base of urinary bladder (Figs. 4 and 5). It extended to the posterior surgical margins. On the immunohistochemical studies, neoplastic cells expressed vimentin and CD34 diffusely (Fig. 6); they were
negative for S-100, desmin, smooth muscle actin, bcl2, CD117, estrogen receptor (ER), progesterone receptor (PR), pan-cytokeratin, and epithelial membrane antigen. Ki-67 proliferative index was below 1%. The pathologic diagnosis was LGFMS, and it was thought to be metastatic from the primary retroperitoneal tumor.
Fig. 5. Tongues of the myxoid neoplasm infiltrating seminal vesicle.
D.E. Baydar, F.T. Aki / Annals of Diagnostic Pathology 15 (2011) 64–68
67
Fig. 6. Immunohistochemical profile of the tumor: negative for S-100 (A) and smooth muscle actin (B), positive for CD34 (C).
The patient received pelvic radiotherapy. He has been free of disease for 3-year follow-up.
3. Discussion Spindle cell lesions of the adult prostate are infrequent and provide a diagnostic challenge to pathologist. Most prostatic mesenchymal tumors are specialized prostatic stromal tumors (stromal sarcomas and stromal tumors of uncertain malignant potential), smooth muscle tumors, and, on rare occasion, solitary fibrous tumors, inflammatory myofibroblastic tumors, and nerve sheath tumors [3,4]. Gastrointestinal stromal tumors may also be sampled on prostate needle biopsy when the tumor is located between the rectum and prostate [5]. Sarcomatoid carcinoma of the prostate is another rare type of cancer that exhibits spindle cell morphology. Our case is an example that metastatic lesions must also be included in the differential diagnosis of the spindle cell tumors of the prostate. Having been informed about the retroperitoneal mass of the patient that was previously removed, we could manage to reach the accurate diagnosis on prostate needle biopsies, which otherwise would be very cumbersome. The prostate very rarely receives metastatic deposits from distant organs. Sarcomas generally use hematogenous as a way for distant spread, and the most common site is the lung.
There are several reports in the literature showing the potency of sarcomas for “seeding,” which usually occurs through the needle tracts or at the laparoscopic portsites [6,7]. Seeding by gravity seems to be one possible way of metastasis to the prostate in our case, since that the primary tumor is retroperitoneal. LGFMS was first described by Evans in 1987 [8]. It is a rare mesenchymal tumor that affects both men and women equally, and typically involves the deep soft tissues of the proximal extremities and trunk (mostly in young to middle-aged adults, even though it can be seen at any age). The retroperitoneum and abdominal cavity are distinctly unusual locations but have been reported [9,10]. The tumor in our case shows the morphologic characteristics of LGFMS, noted by a proliferation of fibroblastic spindle cells in a whorled pattern with sharply delineated fibrous and myxoid areas without significant cellular pleomorphism and mitosis. Although described as paradoxically aggressive neoplasm in the first reports, recent series have stated better prognosis with recurrences, metastases, and death from disease in only 9%, 6%, and 2% of patients, respectively [9]. LGFMS may metastasize many years after initial diagnosis, and indefinite clinical follow-up is mandatory for patients with this disease. Immunohistochemistry supports the fibroblastic nature of the LGFMS, and can be useful in the diagnosis of this disease to exclude other entities that may enter into the
68
D.E. Baydar, F.T. Aki / Annals of Diagnostic Pathology 15 (2011) 64–68
differential. Vimentin is the only positive marker in most LGFMSs. In our case, the tumor also expressed CD34 diffusely. CD34 immunostaining is known to be present in specialized stromal tumors of the prostate, solitary fibrous tumors, and gastrointestinal stromal tumors as well. These entities can arise in the prostate or in adjacent organs and were considered in our differential diagnosis. However, the typical morphology, lack of sex hormone receptors, and CD117 negativity, in addition to the clinical history, let us designate the lesion as metastatic LGFMS. LGFMSs bear either the t(7,16) (q32-34;p11) or t(11,16) (p11;p11) translocations, resulting in FUS-CREB3L2 or FUSCREB3L1 fusions, respectively [11]. Molecular genetic or cytogenetic analyses can be used as auxiliary diagnostic tools if needed. In conclusion, metastatic sarcomas to the prostate can occur and may bear a resemblance to a primary prostatic neoplasm. One should remember to review the complete medical history of the patient and exclude secondary involvement of the organ by metastasis before diagnosing a rare primary spindle cell tumor on a prostate biopsy.
Acknowledgment We present our special thanks to Dr Jonathan I. Epstein and Dr Elizabeth Montgomery from the Department of Pathology, The Johns Hopkins Hospital. Both experts reviewed our case and concurred with the diagnosis.
References [1] Bates AW, Baithun SI. Secondary solid neoplasms of the prostate: a clinico-pathological series of 51 cases. Virchows Arch 2002;440 (4):392-6. [2] Zein TA, Huben R, Lane W, Pontes JE, Englander LS. Secondary tumors of the prostate. J Urol 1985;133(4):615-6. [3] Gaudin PB, Rosai J, Epstein JI. Sarcomas and related proliferative lesions of specialized prostatic stroma: a clinicopathologic study of 22 cases. Am J Surg Pathol 1998;22:148-62. [4] Herawi M, Epstein JI. Specialized stromal tumors of the prostate: a clinicopathologic study of 50 cases. Am J Surg Pathol 2006;30(6):694-704. [5] Herawi M, Montgomery EA, Epstein JI. Gastrointestinal stromal tumors (GISTs) on prostate needle biopsy: a clinicopathologic study of 8 cases. Am J Surg Pathol 2006;30(11):1389-95. [6] Hidai H, Sakuramoto T, Miura T, et al. Needle tract seeding following puncture of retroperitoneal liposarcoma. Eur Urol 1983;9(6):368-9. [7] Clark MA, Thomas JM. Portsite recurrence after laparoscopy for staging of retroperitoneal sarcoma. Surg Laparosc Endosc Percutan Tech 2003;13(4):290-1. [8] Evans HL. Low-grade fibromyxoid sarcoma. A report of two metastasizing neoplasms having a deceptively benign appearance. Am J Clin Pathol 1987;88:615-9. [9] Folpe AL, Lane KL, Paull G, et al. Low-grade fibromyxoid sarcoma and hyalinizing spindle cell tumor with giant rosettes: a clinicopathologic study of 73 cases supporting their identity and assessing the impact of high-grade areas. Am J Surg Pathol 2000;24:1353-60. [10] Koishi A, Gomibuchi H, Inoue J, et al. Hyalinizing spindle cell tumor with giant rosettes of the omentum. J Obstet Gynaecol Res 2003;29:388-91. [11] Guillou L, Benhattar J, Gengler C, et al. Translocation-positive low-grade fibromyxoid sarcoma: clinicopathologic and molecular analysis of a series expanding the morphologic spectrum and suggesting potential relationship to sclerosing epithelioid fibrosarcoma: a study from the French Sarcoma Group. Am J Surg Pathol 2007;31(9):1387-402.