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Renal angiomyolipoma with liposarcomatous transformation: A case report and review of the literature
Urologic Oncology: Seminars and Original Investigations 22 (2004) 425– 427
Original article
Renal angiomyolipoma with liposarcomatous transformation: a case report and review of the literature Shahin Chandrasoma, B.S., Siamak Daneshmand, M.D.*, Shandra Wilson, M.D., Eila C. Skinner, M.D. Department of Urology, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA Received 22 August 2003; received in revised form 14 November 2003; accepted 25 November 2003
Abstract Renal angiomyolipoma is generally benign, although an uncommon subtype (epithelioid angiomyolipoma) may behave more aggressively. Sarcomatous transformation of the disease is exceedingly rare. We report the first case of a high grade round cell liposarcoma arising in a renal angiomyolipoma. © 2004 Elsevier Inc. All rights reserved. Keywords: Angiomyolipoma, Liposarcoma, Kidney
1. Introduction Renal angiomyolipoma occurs both sporadically and in association with tuberous sclerosis [1]. Earlier regarded as a hamartoma, angiomyolipoma is now believed to be neoplastic, showing clonal nonrandom inactivation of the X chromosome [2]. Angiomyolipoma is believed to arise from the perivascular epithelioid cell, which gives rise to the classical polymorphous renal angiomyolipoma that is composed of mature adipose tissue, thick-walled blood vessels and a proliferative spindle cell component [3]. The perivascular epithelioid cell and its cellular derivatives show immunoreactivity for vimentin and melanocyte markers such as HMB45 and MART-1, variably express actin and S100 protein, and are consistently negative for cytokeratin [3]. Though generally regarded as benign, angiomyolipomas rarely produce complicated clinical courses which can be life threatening. It is a common cause of severe perirenal and retroperitoneal hemorrhage. More rarely, they display malignant potential with rapid growth and metastasis. These malignancies associated with angiomyolipoma include malignant epithelioid angiomyolipomas [4 – 6], and sarcomatous transformation of one of the components of the tumor, most commonly leiomyosarcoma [7]. We report the first case of a high grade
* Corresponding author. Tel.: ⫹1-323-865-3700; fax: ⫹1-323-8650120. E-mail address: [email protected] (S. Daneshmand). 1078-1439/$ – see front matter © 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.urolonc.2003.11.013
round cell liposarcoma arising within an angiomyolipoma with its histopathologic and immunoperoxidase staining characteristics.
2. Case reports A 26-year-old male with no significant past medical history presented with a 2 week history of gradually increasing abdominal pain and girth. Computed tomography (CT) scan revealed a 4 cm right-sided renal mass with fat density surrounded by a large retroperitoneal hematoma, radiologically consistent with a hemorrhaging angiomyolipoma. Selective right renal arteriogram showed a long lateral bleeding vessel supplying the tumor, which was subsequently embolized. His hematocrit continued to drop over the next 24 hours, and he was taken to the operating room for right radical nephrectomy and evacuation of the hematoma through a right thoracoabdominal incision. Gross examination revealed a hemorrhagic yellow tumor mass in the central portion of the kidney infiltrating through the capsule into the perirenal adipose tissue (Fig. 1). Histopathologic examination of this tumor revealed the appearance of a classical angiomyolipoma in the central part of the kidney, exhibiting mature adipose tissue and thickwalled blood vessels with associated spindle-cell elements resembling smooth muscle cells (Fig. 2, inset). Arising from this angiomyolipoma and invading the perirenal space extensively was a highly cellular undifferentiated malignant neoplasm consistent with a high grade round cell liposarcoma
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S. Chandrasoma et al. / Urologic Oncology: Seminars and Original Investigations 22 (2004) 425– 427
Fig. 1. Bisected kidney showing mass in the central part of the kidney. The inner part shows adipose tissue and the typical appearance of angiomylipoma. The periphery shows hemorrhage and fleshy, necrotic tissue representing the sarcomatous transformation (arrows). (Color version of figure is available online.)
(Fig. 2). This consisted of small lipoblastic cells with round nuclei embedded in a myxomatous stroma and was associated with necrosis. Immunoperoxidase staining showed the malignant neoplastic cells to be positive for vimentin and negative for cytokeratin, HMB45, S100 protein, actin, desmin, CD45 and CD99. Adjuvant chemotherapy was considered, however, 2 months after nephrectomy the patient presented with widely disseminated peritoneal metastases. He underwent exploratory laparotomy with tumor debulking, however, his disease progressed rapidly without any response to chemotherapy leading to death 1 month later. 3. Discussion Angiomyolipomas are considered benign tumors that generally do not have malignant potential although lymph
node involvement may be seen as a sign of multi-centricity of the tumor [4]. Recently a variant form of the tumor known as a malignant epithelioid angiomyolipoma has been described that is associated with rapid growth and metastasis. Prior reported cases of renal cell carcinoma within angiomyolipomas may in fact have been malignant epithelioid angiomyolipomas that were confused for adenocarcinoma [5–7]. The occurrence of sarcomatous transformation in an angiomyolipoma is exceedingly rare with only two reported cases of leiomyosarcoma complicating angiomyolipoma that led to metastasis and death [8,9]. A round cell liposarcoma arising from a renal angiomyolipoma has not been previously described. Liposarcomas typically arise from the retroperitoneal fat or the peri-renal fat within Gerota’s fascia and compress and displace the kidney as they grow [10]. In contrast, angiomyolipomas arise from the
Fig. 2. Round cell liposarcoma arising from the angiomyolipoma showing highly cellular undifferentiated small lipoblasts in the perinephric space. The inset shows the classical angiomyolipoma in the central part of the renal mass. Hematoxylin and eosin stain. (Color version of figure is available online.)
S. Chandrasoma et al. / Urologic Oncology: Seminars and Original Investigations 22 (2004) 425– 427
kidney causing a defect at the sight of origin. Although liposarcomas can very rarely invade the kidney, the histological pattern of this case precludes this possibility. Care must be exercised in diagnosing sarcomatoid transformation in renal angiomyolipoma. It is not unusual for the spindle cell component in benign angiomyolipoma to show significant cytologic atypia and even increased mitotic activity resulting in a histological resemblance to sarcoma. Renal angiomyolipomas can also invade the renal veins and inferior vena cava [11]. Patients with cytologic atypia and renal vein invasion do not show metastasis and are cured by total tumor removal. As such, these features are not considered to be reliable indicators of sarcomatous transformation in angiomyolipoma and cases that have used these criteria are generally disregarded as being true sarcomatous transformation [8,9]. The diagnosis of malignant liposarcoma arising from the angiomyolipoma was confirmed in this patient by histological analysis of his metastatic disease.
[3] [4] [5]
[6]
[7]
[8]
[9]
References [10] [1] Steiner MS, Goldman SM, Fishman EK, Marshall FF. The natural history of renal angiomyolipoma. J Urol 1993;150:1782– 6. [2] Henske EP, Neumann HP, Scheithauer BW, Herbst EW, Short MP, Kwiatkowski DJ. Loss of heterozygosity in the tuberous sclerosis
[11]
427
(TSC2) region of chromosome band 16p13 occurs in sporadic as well as TSC-associated renal angiomyolipoma. Genes Chrom Cancer 1995;13:295– 8. Eble JN. Angiomyolipoma of kidney. Sem Diag Pathol 1998;15:21– 40. Sant GR, Ucci AA Jr., Meares EM Jr. Multicentric angiomyolipoma: renal and lymph node involvement. Urology 1986;28:111–3. Pea M, Bonetti F, Martignoni G, et al. Apparent renal cell carcinomas in tuberous sclerosis are heterogeneous: the identification of malignant epithelioid angiomyolipoma. Am J Surg Path 1998; 22:180 –7. Eble JN, Amin MB, Young RH. Epithelioid angiomyolipoma of the kidney. A report of five cases with a prominent and diagnostically confusing epithelioid smooth muscle component. Am J Surg Path 1997;21:1123–30. Martignoni G, Pea M, Bonetti F, et al. Carcinomalike monotypic epithelioid angiomyolipoma in patients without evidence of tuberous sclerosis. A clinicopathologic and genetic study. Am J Surg Path 1998;22(6):663–72. Ferry JA, Malt RA, Young RH. Renal angiomyolipoma with sarcomatous transformation and pulmonary metastasis. Am J Surg Path 1991;15:1083– 8. Lowe BA, Brewer J, Houghton DC, et al. Malignant transformation of angiomyolipoma. J Urol 1992;147:1356 – 8. Israel GM, Bosniak MA, Slywotzky CM, Rosen RJ. CT differentiation of large exophytic renal angiomyolipomas and perirenal liposarcomas. AJR Am J Roentgenol 2002;179(3):769 –73. Wilson SS. Clark PE. Stein JP. Angiomyolipoma with vena caval extension. Urology 2002;60(4):695– 6.
Original article
Renal angiomyolipoma with liposarcomatous transformation: a case report and review of the literature Shahin Chandrasoma, B.S., Siamak Daneshmand, M.D.*, Shandra Wilson, M.D., Eila C. Skinner, M.D. Department of Urology, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA Received 22 August 2003; received in revised form 14 November 2003; accepted 25 November 2003
Abstract Renal angiomyolipoma is generally benign, although an uncommon subtype (epithelioid angiomyolipoma) may behave more aggressively. Sarcomatous transformation of the disease is exceedingly rare. We report the first case of a high grade round cell liposarcoma arising in a renal angiomyolipoma. © 2004 Elsevier Inc. All rights reserved. Keywords: Angiomyolipoma, Liposarcoma, Kidney
1. Introduction Renal angiomyolipoma occurs both sporadically and in association with tuberous sclerosis [1]. Earlier regarded as a hamartoma, angiomyolipoma is now believed to be neoplastic, showing clonal nonrandom inactivation of the X chromosome [2]. Angiomyolipoma is believed to arise from the perivascular epithelioid cell, which gives rise to the classical polymorphous renal angiomyolipoma that is composed of mature adipose tissue, thick-walled blood vessels and a proliferative spindle cell component [3]. The perivascular epithelioid cell and its cellular derivatives show immunoreactivity for vimentin and melanocyte markers such as HMB45 and MART-1, variably express actin and S100 protein, and are consistently negative for cytokeratin [3]. Though generally regarded as benign, angiomyolipomas rarely produce complicated clinical courses which can be life threatening. It is a common cause of severe perirenal and retroperitoneal hemorrhage. More rarely, they display malignant potential with rapid growth and metastasis. These malignancies associated with angiomyolipoma include malignant epithelioid angiomyolipomas [4 – 6], and sarcomatous transformation of one of the components of the tumor, most commonly leiomyosarcoma [7]. We report the first case of a high grade
* Corresponding author. Tel.: ⫹1-323-865-3700; fax: ⫹1-323-8650120. E-mail address: [email protected] (S. Daneshmand). 1078-1439/$ – see front matter © 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.urolonc.2003.11.013
round cell liposarcoma arising within an angiomyolipoma with its histopathologic and immunoperoxidase staining characteristics.
2. Case reports A 26-year-old male with no significant past medical history presented with a 2 week history of gradually increasing abdominal pain and girth. Computed tomography (CT) scan revealed a 4 cm right-sided renal mass with fat density surrounded by a large retroperitoneal hematoma, radiologically consistent with a hemorrhaging angiomyolipoma. Selective right renal arteriogram showed a long lateral bleeding vessel supplying the tumor, which was subsequently embolized. His hematocrit continued to drop over the next 24 hours, and he was taken to the operating room for right radical nephrectomy and evacuation of the hematoma through a right thoracoabdominal incision. Gross examination revealed a hemorrhagic yellow tumor mass in the central portion of the kidney infiltrating through the capsule into the perirenal adipose tissue (Fig. 1). Histopathologic examination of this tumor revealed the appearance of a classical angiomyolipoma in the central part of the kidney, exhibiting mature adipose tissue and thickwalled blood vessels with associated spindle-cell elements resembling smooth muscle cells (Fig. 2, inset). Arising from this angiomyolipoma and invading the perirenal space extensively was a highly cellular undifferentiated malignant neoplasm consistent with a high grade round cell liposarcoma
426
S. Chandrasoma et al. / Urologic Oncology: Seminars and Original Investigations 22 (2004) 425– 427
Fig. 1. Bisected kidney showing mass in the central part of the kidney. The inner part shows adipose tissue and the typical appearance of angiomylipoma. The periphery shows hemorrhage and fleshy, necrotic tissue representing the sarcomatous transformation (arrows). (Color version of figure is available online.)
(Fig. 2). This consisted of small lipoblastic cells with round nuclei embedded in a myxomatous stroma and was associated with necrosis. Immunoperoxidase staining showed the malignant neoplastic cells to be positive for vimentin and negative for cytokeratin, HMB45, S100 protein, actin, desmin, CD45 and CD99. Adjuvant chemotherapy was considered, however, 2 months after nephrectomy the patient presented with widely disseminated peritoneal metastases. He underwent exploratory laparotomy with tumor debulking, however, his disease progressed rapidly without any response to chemotherapy leading to death 1 month later. 3. Discussion Angiomyolipomas are considered benign tumors that generally do not have malignant potential although lymph
node involvement may be seen as a sign of multi-centricity of the tumor [4]. Recently a variant form of the tumor known as a malignant epithelioid angiomyolipoma has been described that is associated with rapid growth and metastasis. Prior reported cases of renal cell carcinoma within angiomyolipomas may in fact have been malignant epithelioid angiomyolipomas that were confused for adenocarcinoma [5–7]. The occurrence of sarcomatous transformation in an angiomyolipoma is exceedingly rare with only two reported cases of leiomyosarcoma complicating angiomyolipoma that led to metastasis and death [8,9]. A round cell liposarcoma arising from a renal angiomyolipoma has not been previously described. Liposarcomas typically arise from the retroperitoneal fat or the peri-renal fat within Gerota’s fascia and compress and displace the kidney as they grow [10]. In contrast, angiomyolipomas arise from the
Fig. 2. Round cell liposarcoma arising from the angiomyolipoma showing highly cellular undifferentiated small lipoblasts in the perinephric space. The inset shows the classical angiomyolipoma in the central part of the renal mass. Hematoxylin and eosin stain. (Color version of figure is available online.)
S. Chandrasoma et al. / Urologic Oncology: Seminars and Original Investigations 22 (2004) 425– 427
kidney causing a defect at the sight of origin. Although liposarcomas can very rarely invade the kidney, the histological pattern of this case precludes this possibility. Care must be exercised in diagnosing sarcomatoid transformation in renal angiomyolipoma. It is not unusual for the spindle cell component in benign angiomyolipoma to show significant cytologic atypia and even increased mitotic activity resulting in a histological resemblance to sarcoma. Renal angiomyolipomas can also invade the renal veins and inferior vena cava [11]. Patients with cytologic atypia and renal vein invasion do not show metastasis and are cured by total tumor removal. As such, these features are not considered to be reliable indicators of sarcomatous transformation in angiomyolipoma and cases that have used these criteria are generally disregarded as being true sarcomatous transformation [8,9]. The diagnosis of malignant liposarcoma arising from the angiomyolipoma was confirmed in this patient by histological analysis of his metastatic disease.
[3] [4] [5]
[6]
[7]
[8]
[9]
References [10] [1] Steiner MS, Goldman SM, Fishman EK, Marshall FF. The natural history of renal angiomyolipoma. J Urol 1993;150:1782– 6. [2] Henske EP, Neumann HP, Scheithauer BW, Herbst EW, Short MP, Kwiatkowski DJ. Loss of heterozygosity in the tuberous sclerosis
[11]
427
(TSC2) region of chromosome band 16p13 occurs in sporadic as well as TSC-associated renal angiomyolipoma. Genes Chrom Cancer 1995;13:295– 8. Eble JN. Angiomyolipoma of kidney. Sem Diag Pathol 1998;15:21– 40. Sant GR, Ucci AA Jr., Meares EM Jr. Multicentric angiomyolipoma: renal and lymph node involvement. Urology 1986;28:111–3. Pea M, Bonetti F, Martignoni G, et al. Apparent renal cell carcinomas in tuberous sclerosis are heterogeneous: the identification of malignant epithelioid angiomyolipoma. Am J Surg Path 1998; 22:180 –7. Eble JN, Amin MB, Young RH. Epithelioid angiomyolipoma of the kidney. A report of five cases with a prominent and diagnostically confusing epithelioid smooth muscle component. Am J Surg Path 1997;21:1123–30. Martignoni G, Pea M, Bonetti F, et al. Carcinomalike monotypic epithelioid angiomyolipoma in patients without evidence of tuberous sclerosis. A clinicopathologic and genetic study. Am J Surg Path 1998;22(6):663–72. Ferry JA, Malt RA, Young RH. Renal angiomyolipoma with sarcomatous transformation and pulmonary metastasis. Am J Surg Path 1991;15:1083– 8. Lowe BA, Brewer J, Houghton DC, et al. Malignant transformation of angiomyolipoma. J Urol 1992;147:1356 – 8. Israel GM, Bosniak MA, Slywotzky CM, Rosen RJ. CT differentiation of large exophytic renal angiomyolipomas and perirenal liposarcomas. AJR Am J Roentgenol 2002;179(3):769 –73. Wilson SS. Clark PE. Stein JP. Angiomyolipoma with vena caval extension. Urology 2002;60(4):695– 6.