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Renal angiofibroma: A case report
Human Pathology: Case Reports 12 (2018) 29–31
Contents lists available at ScienceDirect
Human Pathology: Case Reports journal homepage: www.elsevier.com/locate/ehpc
Case Report
Renal angiofibroma: A case report a
b
Wei Chen, M.D. , Carmen J. Julius, M.D. , Robin M. Elliott, M.D. a b
a,⁎
T
University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH, United States Mercy Health Laboratories, Mercy Health-Youngstown, Youngstown, OH, United States
A R T I C L E I N F O
A B S T R A C T
Keywords: Angiofibroma Kidney Case
A 28 year-old woman presenting with abdominal pain was found by CT scan to have a 5.7 cm mass in the right kidney. Examination of the nephrectomy specimen revealed a tumor with histopathologic features consistent with angiofibroma, an entity heretofore described only the nasopharynx, genital region, and somatic soft tissue.
1. Introduction Angiofibromas are defined as benign fibroblastic neoplasms with prominent vasculature and have been encountered as three distinct clinicopathologic entities: those occurring in the nasopharynx (frequently associated with tuberous sclerosis), those occurring in the genital region (cellular angiofibroma), and mostly recently, those occurring in somatic soft tissue. Herein, we describe a tumor with the histopathologic features of soft tissue angiofibroma occurring in the kidney. 2. Case presentation A 28-year-old woman presented to the emergency department with right upper quadrant pain. An abdominal CT scan revealed a 5.7 × 5.2 × 4.7 cm exophytic, solid, heterogeneous mass involving the superior pole of the right kidney. No history of tuberous sclerosis or other renal tumor related heredity syndrome was reported. The patient underwent laparoscopic right nephrectomy five months later. At nine months follow-up, there was no evidence of disease. 3. Pathological findings A 6.5 cm well-circumscribed mass was identified in the upper pole of the kidney (Fig. 1A). The cut surface was homogenous gray-white, smooth, and firm without hemorrhage or necrosis. Microscopic sections showed a variably cellular neoplasm composed of bland spindle cells in a collagenous and focally myxoid background (Fig. 1B). Less cellular areas appeared variably hyalinized or edematous. The tumor contained numerous blood vessels of varying size and shape (Fig. 1C), the vast majority of which were small, thin-walled, and
branching. A few larger slit-like or staghorn vessels with variably thick walls resembling those of solitary fibrous tumor (SFT) were also noted. On high power, the spindle cells were monomorphic with ovoid or tapering nuclei containing fine chromatin and indistinct, lightly eosinophilic cytoplasm (Fig. 1D). Mitotic activity and necrosis were not identified. Immunohistochemical stains demonstrated the tumor cells to be positive for vimentin, smooth muscle actin (SMA) (Fig. 2A), bcl-2 and PR; weakly and focally positive for CD10; and negative for S100, CD34, CD31, cytokeratin AE1/AE3, CK7, CK20, CD117, desmin, STAT6, ER, melan A, HMB-45, and CD99. The vascular pattern was highlighted by CD34 staining of the endothelial cells. (Fig. 2B). 4. Discussion Angiofibroma of soft tissue (AST) has been recently recognized as a benign mesenchymal tumor characterized by bland spindle cells and a highly developed branching capillary network [1]. It occurs predominantly in women with a wide age range. Sixty-two cases have been reported since 2012, most frequently in the lower extremities, often adjacent to joints [2–5]. Unusual anatomic locations include the back, abdominal wall, pelvic cavity, and breast. Although its name infers that this tumor would be restricted to somatic soft tissue, it is conceivable that tumors with identical histological features could occur elsewhere, even in visceral sites. Before accepting a diagnosis of angiofibroma of the kidney, one must be careful to rule out potential mimics. The differential diagnosis includes both benign and malignant renal tumors, including angiomyolipoma (AML), leiomyoma, medullary fibroma, solitary fibrous tumor (SFT), low grade fibromyxoid sarcoma (LGFMS), myxofibrosarcoma and myxoid liposarcoma.
⁎ Corresponding author at: Assistant Professor of Pathology, Case Western Reserve University School of Medicine, University Hospitals Cleveland Medical Center, 11100 Euclid Ave, Cleveland, OH 44106, United States. E-mail address: [email protected] (R.M. Elliott).
https://doi.org/10.1016/j.ehpc.2018.01.001 Received 11 June 2017; Received in revised form 9 December 2017; Accepted 3 January 2018 2214-3300/ © 2018 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/).
Human Pathology: Case Reports 12 (2018) 29–31
W. Chen et al.
Fig. 1. (A) Grossly, the tumor is well-circumscribed with grey cut surface. (B) In a lower-power view, tumor has complete capsule separating from kidney parenchyma (HE stain, 40X); (C) Cells are scattered in a background of edematous stroma and highly developed arborizing vessels. (HE stain, 100X); (D) Spindle cells with palely eosinophilic cytoplasm, short, ovoid or tapering nuclei and fine chromatin (HE stain, 200X).
An important benign entity to be considered in the evaluation of a spindle cell neoplasm within the kidney is AML. These tumors arise from perivascular epithelioid cells (PEC) and are often associated with tuberous sclerosis. Although the lipid poor variant could potentially mimic an angiofibroma, AMLs are characterized by smooth muscle cells arranged in fascicles admixed with mature fat and thick-walled blood vessels. Positive immunohistochemistry for melanocytic markers, including melan A and HMB-45, supports a diagnosis of AML. Leiomyomas, derived from the walls of renal vessels, may occur in the kidney and may enter the differential diagnosis, however, these would express desmin and would not feature the highly developed branching capillary network seen in AST. Lastly among benign entities, we mention renomedullary interstitial cell tumor or medullary fibroma, a small tumor that commonly presents as an incidental finding. It usually measures less than 5 mm in diameter and is not known to cause clinical symptoms. In addition to benign tumors, the differential diagnosis includes tumors that possess varying degrees of malignant potential, from “intermediate” to fully malignant. Among these, SFT is the most likely to mimic AST. SFTs occur in a variety of locations outside the pleura including the kidney [6]. Around 50 cases of primary renal SFTs have been described in the literature [7–9]. Myxoid SFTs especially should be considered in the differential diagnosis, as they may exhibit both bland spindle cells and myxoid stroma. SFTs, however, typically show “patternless” architecture and usually do not display the innumerable, evenly distributed, branching thin-walled vessels characteristic of angiofibroma. Furthermore, most SFTs express CD34 and nearly all express STAT6. Neither marker was expressed in our case. LGFMS was not recognized as a malignant neoplasm until 1987. It typically affects young patients (median age, 35 years) presenting as a long-standing, painless mass in deep soft tissues of the limbs, limb girdles, and trunk. Five cases of renal LGFMS have been reported [10–12]. LGFMS shows alternating collagenous and myxoid areas with a swirling growth pattern and bland spindle cell morphology; however, it lacks the vascularity typically encountered in angiofbroma. Ninety percent of cases of LGFMS express CD99 and BCL-2, neither of which was expressed in our case. Myxofibrosarcoma may enter the differential, however, myxofibrosarcomas usually show obvious features of malignancy and elongated curvilinear vessels, which are easily distinguished from the
Fig. 2. The immunohistochemical stains. (A) showed the cytoplasmic staining of SMA in myofibroblasts. (B) showed that CD34 is negative in tumor cells and only vessels are highlighted.
30
Human Pathology: Case Reports 12 (2018) 29–31
W. Chen et al.
vascular network of angiofibroma. Only a single case of renal myxofibrosarcoma has been reported to date [13]. Myxoid liposarcomas account for about 30% to 35% of all liposarcomas. Four cases of myxoid liposarcoma of the kidney have been reported in the English literature [14,15]. These exhibit a prominent plexiform network of thin-walled capillaries, which resembles the vascular network seen in AST. However, even the smallest vessels of ASTs have considerably thicker vessel walls compared with the vessels of myxoid liposarcoma. Vasculature features aside, our case showed no evidence of adipocytic differentiation.
[2] M.A. Edgar, S.R. Lauer, J.A. Bridge, et al., Soft tissue angiofibroma: report of 2 cases of a recently described tumor, Hum. Pathol. 44 (2013) 438–441. [3] Y. Jin, E. Moller, K.H. Nord, et al., Fusion of the AHRR and NCOA2 genes through a recurrent translocation t(5;8)(p15;q13) in soft tissue angiofibroma results in upregulation of aryl hydrocarbon receptor target genes, Genes Chromosomes Cancer 51 (2012) 510–520. [4] J.S. Song, S. Park, J.S. Lee, et al., Angiofibroma of soft tissue: a recently described entity, Pathol. Int. 64 (2014) 289–291. [5] Y. Yamada, H. Yamamoto, K. Kohashi, et al., Histological Spectrum of Angiofibroma of Soft Tissue: Histological and genetic analysis of 13 cases, Histopathology 69 (3) (2016) 459–469. [6] J.K. Chan, Solitary fibrous tumour—everywhere, and a diagnosis in vogue, Histopathology 31 (1997) 568–576. [7] R. Nakajima, K. Abe, T. Kondo, et al., FDG-PET/CT and CT findings of a benign solitary fibrous tumor of the kidney; correlation with pathology, Asia Ocean J. Nucl. Med. Biol. 3 (2015) 116–119. [8] A.K. Shanbhogue, S.R. Prasad, N. Takahashi, et al., Somatic and visceral solitary fibrous tumors in the abdomen and pelvis: cross-sectional imaging spectrum, Radiographics 31 (2011) 393–408. [9] P. Tritschler, B. Coulier, I. Gielen, Solitary fibrous tumor of the kidney, JBR-BTR 97 (2014) 298–300. [10] G.N. del Valle, L.J. Santos, O.J. Martinez-Sagarra, et al., Fibromyxoid sarcoma of kidney, Actas Urol. Esp. 33 (2009) 1036–1039. [11] J.C. Rubinstein, A. Visa, L. Zhang, et al., Primary low-grade fibromyxoid sarcoma of the kidney in a child with the alternative EWSR1-CREB3L1 gene fusion, Pediatr. Dev. Pathol. 17 (2014) 321–326. [12] J.F. Silverman, G. Nathan, P.R. Olson, et al., Fine-needle aspiration cytology of lowgrade fibromyxoid sarcoma of the renal capsule (capsuloma), Diagn. Cytopathol. 23 (2000) 279–283. [13] J.F. Val-Bernal, M.R. Garcia-Gonzalez, M. Mayorga, et al., Primary renal myxofibrosarcoma, Pathol. Res. Pract. 211 (2015) 619–624. [14] N. Crisan, C.S. Ivan, C. Bungardean, et al., Retroperitoneal perirenal myxoid liposarcoma, J. Surg. Case. Rep. 2015 (2015). [15] J.R. Tysome, A. Sandison, P.M. Clarke, Myxoid liposarcoma metastatic to the thyroid gland: a case report and literature review, J. Laryngol. Otol. 120 (2006) 511–513.
5. Conclusion AST is a recently described tumor that, to date, has only been reported in somatic sites. Our case demonstrates that a similar, if not identical, neoplasm may arise in a visceral site. Awareness of the unique histopathologic features of these lesions should readily allow for their distinction from other, more aggressive mesenchymal tumors. Conflict of interest The authors report no conflicts of interest with the submission of this manuscript. References [1] A. Marino-Enriquez, C.D. Fletcher, Angiofibroma of soft tissue: clinicopathologic characterization of a distinctive benign fibrovascular neoplasm in a series of 37 cases, Am. J. Surg. Pathol. 36 (2012) 500–508.
31
Contents lists available at ScienceDirect
Human Pathology: Case Reports journal homepage: www.elsevier.com/locate/ehpc
Case Report
Renal angiofibroma: A case report a
b
Wei Chen, M.D. , Carmen J. Julius, M.D. , Robin M. Elliott, M.D. a b
a,⁎
T
University Hospitals Cleveland Medical Center, Case Western Reserve University School of Medicine, Cleveland, OH, United States Mercy Health Laboratories, Mercy Health-Youngstown, Youngstown, OH, United States
A R T I C L E I N F O
A B S T R A C T
Keywords: Angiofibroma Kidney Case
A 28 year-old woman presenting with abdominal pain was found by CT scan to have a 5.7 cm mass in the right kidney. Examination of the nephrectomy specimen revealed a tumor with histopathologic features consistent with angiofibroma, an entity heretofore described only the nasopharynx, genital region, and somatic soft tissue.
1. Introduction Angiofibromas are defined as benign fibroblastic neoplasms with prominent vasculature and have been encountered as three distinct clinicopathologic entities: those occurring in the nasopharynx (frequently associated with tuberous sclerosis), those occurring in the genital region (cellular angiofibroma), and mostly recently, those occurring in somatic soft tissue. Herein, we describe a tumor with the histopathologic features of soft tissue angiofibroma occurring in the kidney. 2. Case presentation A 28-year-old woman presented to the emergency department with right upper quadrant pain. An abdominal CT scan revealed a 5.7 × 5.2 × 4.7 cm exophytic, solid, heterogeneous mass involving the superior pole of the right kidney. No history of tuberous sclerosis or other renal tumor related heredity syndrome was reported. The patient underwent laparoscopic right nephrectomy five months later. At nine months follow-up, there was no evidence of disease. 3. Pathological findings A 6.5 cm well-circumscribed mass was identified in the upper pole of the kidney (Fig. 1A). The cut surface was homogenous gray-white, smooth, and firm without hemorrhage or necrosis. Microscopic sections showed a variably cellular neoplasm composed of bland spindle cells in a collagenous and focally myxoid background (Fig. 1B). Less cellular areas appeared variably hyalinized or edematous. The tumor contained numerous blood vessels of varying size and shape (Fig. 1C), the vast majority of which were small, thin-walled, and
branching. A few larger slit-like or staghorn vessels with variably thick walls resembling those of solitary fibrous tumor (SFT) were also noted. On high power, the spindle cells were monomorphic with ovoid or tapering nuclei containing fine chromatin and indistinct, lightly eosinophilic cytoplasm (Fig. 1D). Mitotic activity and necrosis were not identified. Immunohistochemical stains demonstrated the tumor cells to be positive for vimentin, smooth muscle actin (SMA) (Fig. 2A), bcl-2 and PR; weakly and focally positive for CD10; and negative for S100, CD34, CD31, cytokeratin AE1/AE3, CK7, CK20, CD117, desmin, STAT6, ER, melan A, HMB-45, and CD99. The vascular pattern was highlighted by CD34 staining of the endothelial cells. (Fig. 2B). 4. Discussion Angiofibroma of soft tissue (AST) has been recently recognized as a benign mesenchymal tumor characterized by bland spindle cells and a highly developed branching capillary network [1]. It occurs predominantly in women with a wide age range. Sixty-two cases have been reported since 2012, most frequently in the lower extremities, often adjacent to joints [2–5]. Unusual anatomic locations include the back, abdominal wall, pelvic cavity, and breast. Although its name infers that this tumor would be restricted to somatic soft tissue, it is conceivable that tumors with identical histological features could occur elsewhere, even in visceral sites. Before accepting a diagnosis of angiofibroma of the kidney, one must be careful to rule out potential mimics. The differential diagnosis includes both benign and malignant renal tumors, including angiomyolipoma (AML), leiomyoma, medullary fibroma, solitary fibrous tumor (SFT), low grade fibromyxoid sarcoma (LGFMS), myxofibrosarcoma and myxoid liposarcoma.
⁎ Corresponding author at: Assistant Professor of Pathology, Case Western Reserve University School of Medicine, University Hospitals Cleveland Medical Center, 11100 Euclid Ave, Cleveland, OH 44106, United States. E-mail address: [email protected] (R.M. Elliott).
https://doi.org/10.1016/j.ehpc.2018.01.001 Received 11 June 2017; Received in revised form 9 December 2017; Accepted 3 January 2018 2214-3300/ © 2018 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/).
Human Pathology: Case Reports 12 (2018) 29–31
W. Chen et al.
Fig. 1. (A) Grossly, the tumor is well-circumscribed with grey cut surface. (B) In a lower-power view, tumor has complete capsule separating from kidney parenchyma (HE stain, 40X); (C) Cells are scattered in a background of edematous stroma and highly developed arborizing vessels. (HE stain, 100X); (D) Spindle cells with palely eosinophilic cytoplasm, short, ovoid or tapering nuclei and fine chromatin (HE stain, 200X).
An important benign entity to be considered in the evaluation of a spindle cell neoplasm within the kidney is AML. These tumors arise from perivascular epithelioid cells (PEC) and are often associated with tuberous sclerosis. Although the lipid poor variant could potentially mimic an angiofibroma, AMLs are characterized by smooth muscle cells arranged in fascicles admixed with mature fat and thick-walled blood vessels. Positive immunohistochemistry for melanocytic markers, including melan A and HMB-45, supports a diagnosis of AML. Leiomyomas, derived from the walls of renal vessels, may occur in the kidney and may enter the differential diagnosis, however, these would express desmin and would not feature the highly developed branching capillary network seen in AST. Lastly among benign entities, we mention renomedullary interstitial cell tumor or medullary fibroma, a small tumor that commonly presents as an incidental finding. It usually measures less than 5 mm in diameter and is not known to cause clinical symptoms. In addition to benign tumors, the differential diagnosis includes tumors that possess varying degrees of malignant potential, from “intermediate” to fully malignant. Among these, SFT is the most likely to mimic AST. SFTs occur in a variety of locations outside the pleura including the kidney [6]. Around 50 cases of primary renal SFTs have been described in the literature [7–9]. Myxoid SFTs especially should be considered in the differential diagnosis, as they may exhibit both bland spindle cells and myxoid stroma. SFTs, however, typically show “patternless” architecture and usually do not display the innumerable, evenly distributed, branching thin-walled vessels characteristic of angiofibroma. Furthermore, most SFTs express CD34 and nearly all express STAT6. Neither marker was expressed in our case. LGFMS was not recognized as a malignant neoplasm until 1987. It typically affects young patients (median age, 35 years) presenting as a long-standing, painless mass in deep soft tissues of the limbs, limb girdles, and trunk. Five cases of renal LGFMS have been reported [10–12]. LGFMS shows alternating collagenous and myxoid areas with a swirling growth pattern and bland spindle cell morphology; however, it lacks the vascularity typically encountered in angiofbroma. Ninety percent of cases of LGFMS express CD99 and BCL-2, neither of which was expressed in our case. Myxofibrosarcoma may enter the differential, however, myxofibrosarcomas usually show obvious features of malignancy and elongated curvilinear vessels, which are easily distinguished from the
Fig. 2. The immunohistochemical stains. (A) showed the cytoplasmic staining of SMA in myofibroblasts. (B) showed that CD34 is negative in tumor cells and only vessels are highlighted.
30
Human Pathology: Case Reports 12 (2018) 29–31
W. Chen et al.
vascular network of angiofibroma. Only a single case of renal myxofibrosarcoma has been reported to date [13]. Myxoid liposarcomas account for about 30% to 35% of all liposarcomas. Four cases of myxoid liposarcoma of the kidney have been reported in the English literature [14,15]. These exhibit a prominent plexiform network of thin-walled capillaries, which resembles the vascular network seen in AST. However, even the smallest vessels of ASTs have considerably thicker vessel walls compared with the vessels of myxoid liposarcoma. Vasculature features aside, our case showed no evidence of adipocytic differentiation.
[2] M.A. Edgar, S.R. Lauer, J.A. Bridge, et al., Soft tissue angiofibroma: report of 2 cases of a recently described tumor, Hum. Pathol. 44 (2013) 438–441. [3] Y. Jin, E. Moller, K.H. Nord, et al., Fusion of the AHRR and NCOA2 genes through a recurrent translocation t(5;8)(p15;q13) in soft tissue angiofibroma results in upregulation of aryl hydrocarbon receptor target genes, Genes Chromosomes Cancer 51 (2012) 510–520. [4] J.S. Song, S. Park, J.S. Lee, et al., Angiofibroma of soft tissue: a recently described entity, Pathol. Int. 64 (2014) 289–291. [5] Y. Yamada, H. Yamamoto, K. Kohashi, et al., Histological Spectrum of Angiofibroma of Soft Tissue: Histological and genetic analysis of 13 cases, Histopathology 69 (3) (2016) 459–469. [6] J.K. Chan, Solitary fibrous tumour—everywhere, and a diagnosis in vogue, Histopathology 31 (1997) 568–576. [7] R. Nakajima, K. Abe, T. Kondo, et al., FDG-PET/CT and CT findings of a benign solitary fibrous tumor of the kidney; correlation with pathology, Asia Ocean J. Nucl. Med. Biol. 3 (2015) 116–119. [8] A.K. Shanbhogue, S.R. Prasad, N. Takahashi, et al., Somatic and visceral solitary fibrous tumors in the abdomen and pelvis: cross-sectional imaging spectrum, Radiographics 31 (2011) 393–408. [9] P. Tritschler, B. Coulier, I. Gielen, Solitary fibrous tumor of the kidney, JBR-BTR 97 (2014) 298–300. [10] G.N. del Valle, L.J. Santos, O.J. Martinez-Sagarra, et al., Fibromyxoid sarcoma of kidney, Actas Urol. Esp. 33 (2009) 1036–1039. [11] J.C. Rubinstein, A. Visa, L. Zhang, et al., Primary low-grade fibromyxoid sarcoma of the kidney in a child with the alternative EWSR1-CREB3L1 gene fusion, Pediatr. Dev. Pathol. 17 (2014) 321–326. [12] J.F. Silverman, G. Nathan, P.R. Olson, et al., Fine-needle aspiration cytology of lowgrade fibromyxoid sarcoma of the renal capsule (capsuloma), Diagn. Cytopathol. 23 (2000) 279–283. [13] J.F. Val-Bernal, M.R. Garcia-Gonzalez, M. Mayorga, et al., Primary renal myxofibrosarcoma, Pathol. Res. Pract. 211 (2015) 619–624. [14] N. Crisan, C.S. Ivan, C. Bungardean, et al., Retroperitoneal perirenal myxoid liposarcoma, J. Surg. Case. Rep. 2015 (2015). [15] J.R. Tysome, A. Sandison, P.M. Clarke, Myxoid liposarcoma metastatic to the thyroid gland: a case report and literature review, J. Laryngol. Otol. 120 (2006) 511–513.
5. Conclusion AST is a recently described tumor that, to date, has only been reported in somatic sites. Our case demonstrates that a similar, if not identical, neoplasm may arise in a visceral site. Awareness of the unique histopathologic features of these lesions should readily allow for their distinction from other, more aggressive mesenchymal tumors. Conflict of interest The authors report no conflicts of interest with the submission of this manuscript. References [1] A. Marino-Enriquez, C.D. Fletcher, Angiofibroma of soft tissue: clinicopathologic characterization of a distinctive benign fibrovascular neoplasm in a series of 37 cases, Am. J. Surg. Pathol. 36 (2012) 500–508.
31