Figure 1
Anatomic pathology
Solitary fibrous tumour of the kidney
SectionUroradiology & genital male imaging
Case TypeClinical Cases
AuthorsMarta E. Hernández García, Begoña Diaz Barroso, Carolina Sainz Azara, Gabriel Olmedilla Arregui, Óscar Rueda Elias, Mª Ángeles Cruz Diaz
Connected authors
67 years, female
Clinical History
A 67-year-old woman was referred to the digestive health specialist for study of chronic abdominal pain.
Imaging Findings
On CT we observed a well-defined 7 cm solid mass arising from the middle region of the left kidney, with heterogeneous attenuation higher in the periphery. It had small calcifications in the wall. This lesion contacted the left renal artery and vein, which were permeable.
There were small retroperitoneal left-paraaortic lymph nodes, under 5 mm.
There were small retroperitoneal left-paraaortic lymph nodes, under 5 mm.
Discussion
PATHOLOGIC FINDINGS:
At gross pathologic analysis the tumour appeared as a well-defined, firm mass with a grey-white shade measuring 6 x 8 x 7 cm, composed of a proliferation of highly cellular spindle cells with mild atypia. They were arranged in a storiform pattern in some areas and between thick bundles of collagen in other areas.
No significant necrosis, haemorrhage or cellular pleomorphism was seen.
The tumour strongly expressed CD34, vimentin and showed a weak immunohistochemical reaction for Cd99, Bcl2 and HHF-35. There were no reactions for Desmin, EMA, CkAe1-Ae3, melan-a, S-100 or Hmb-45.
DISCUSSION:
Solitary fibrous tumours (SFT) are rare mesenchymal neoplasms. They frequently arise from the serosal surface, most commonly seen in the pleural cavity. Extrapleural SFTs are very uncommon, and to our knowledge, there are less than 50 published cases of SFTs located in the kidney [1]. SFT diagnosis is more frequent during the fifth and sixth decades of life, without significant sex predilection [2].
Histologically, SFTs are distinctive mesenchymal tumours characterized by a well-defined mass composed of a proliferation of spindle cells embedded in a collagenous stroma, with an increase in vascularization with thin-walled blood vessels showing a typical staghorn pattern [3].
The diagnosis is confirmed by characteristic positive immunohistochemical staining for CD34 and negative staining for S-100 [1, 4].
Extrapleural SFTs typically manifest as large, slow-growing soft-tissue neoplasms [4].
Although most extrapleural SFTs have a benign clinical course, up to 15% of these tumours demonstrate aggressive behaviour in the form of recurrence or malignancy [4]
Malignancy probability increases with the size of the tumour [5]
SFT are often incidentally found at CT studies, although their appearance is nonspecific and prompts further investigations [2]
Clinically, most patients are asymptomatic or have pain secondary to a mass effect due to the size of the tumour [6, 7].
The tumour can involve the renal cortex, peripelvis, renal capsule, or extrarenal soft tissue [6]
The radiologic findings of renal solitary fibrous tumour are [2, 6]:
- On ultrasound renal solitary fibrous tumours appear as hypo or heterogeneous echoic masses, and as hypoechoic masses with intratumoural vascularity on Doppler ultrasound.
- Contrast-enhanced CT may reveal a well-circumscribed smooth lobulated solid enhancing mass that contains areas of cystic degeneration.
- MRI usually demonstrates a signal intensity on T1- weighted images and inhomogeneous high or low intensity on T2-weighted images.
In differential diagnosis, the most useful tool is diffuse CD34 positivity to distinguish it from other spindle cell tumours of the kidney [7].
Complete excision and follow-up for recurrence are recommended for both benign and malignant SFT [2, 8].
At gross pathologic analysis the tumour appeared as a well-defined, firm mass with a grey-white shade measuring 6 x 8 x 7 cm, composed of a proliferation of highly cellular spindle cells with mild atypia. They were arranged in a storiform pattern in some areas and between thick bundles of collagen in other areas.
No significant necrosis, haemorrhage or cellular pleomorphism was seen.
The tumour strongly expressed CD34, vimentin and showed a weak immunohistochemical reaction for Cd99, Bcl2 and HHF-35. There were no reactions for Desmin, EMA, CkAe1-Ae3, melan-a, S-100 or Hmb-45.
DISCUSSION:
Solitary fibrous tumours (SFT) are rare mesenchymal neoplasms. They frequently arise from the serosal surface, most commonly seen in the pleural cavity. Extrapleural SFTs are very uncommon, and to our knowledge, there are less than 50 published cases of SFTs located in the kidney [1]. SFT diagnosis is more frequent during the fifth and sixth decades of life, without significant sex predilection [2].
Histologically, SFTs are distinctive mesenchymal tumours characterized by a well-defined mass composed of a proliferation of spindle cells embedded in a collagenous stroma, with an increase in vascularization with thin-walled blood vessels showing a typical staghorn pattern [3].
The diagnosis is confirmed by characteristic positive immunohistochemical staining for CD34 and negative staining for S-100 [1, 4].
Extrapleural SFTs typically manifest as large, slow-growing soft-tissue neoplasms [4].
Although most extrapleural SFTs have a benign clinical course, up to 15% of these tumours demonstrate aggressive behaviour in the form of recurrence or malignancy [4]
Malignancy probability increases with the size of the tumour [5]
SFT are often incidentally found at CT studies, although their appearance is nonspecific and prompts further investigations [2]
Clinically, most patients are asymptomatic or have pain secondary to a mass effect due to the size of the tumour [6, 7].
The tumour can involve the renal cortex, peripelvis, renal capsule, or extrarenal soft tissue [6]
The radiologic findings of renal solitary fibrous tumour are [2, 6]:
- On ultrasound renal solitary fibrous tumours appear as hypo or heterogeneous echoic masses, and as hypoechoic masses with intratumoural vascularity on Doppler ultrasound.
- Contrast-enhanced CT may reveal a well-circumscribed smooth lobulated solid enhancing mass that contains areas of cystic degeneration.
- MRI usually demonstrates a signal intensity on T1- weighted images and inhomogeneous high or low intensity on T2-weighted images.
In differential diagnosis, the most useful tool is diffuse CD34 positivity to distinguish it from other spindle cell tumours of the kidney [7].
Complete excision and follow-up for recurrence are recommended for both benign and malignant SFT [2, 8].
Differential Diagnosis List
Solitary fibrous tumour of the kidney
Renal cell carcinoma (subtype clear cell)
Oncocytoma
Mesenchymal tumours
Lymphoma
Final Diagnosis
Solitary fibrous tumour of the kidney
References
[1] Naoto Kuroda, Chisato Ohe, Noriko Sakaida, Yoshiko Uemura, Keiji Inoue, Yoji Nagashima, Ondrej Hes, Michal Michal (2014) Solitary fibrous tumor of the kidney with focus on clinical and pathobiological aspects. Int J Clin Exp Pathol 7(6):2737-2742 (PMID: 25031693)
[2] Daniel T. Ginat, Aqiba Bokhari, Shweta Bhatt, and Vikram Dogra (2011) Imaging Features of Solitary Fibrous Tumors. American Journal of Roentgenology 196: 487-495 (PMID: 21343490)
[3] Alampady K. Shanbhogue, MD; Srinivasa R. Prasad, MD; Naoki Takahashi, MD; Raghunandan Vikram, MBBS, MRCP, FRCR; Atif Zaheer, MD; Kumaresan Sandrasegaran, MD. (2011) Somatic and Visceral Solitary Fibrous Tumors in the Abdomen and Pelvis: Cross-sectional Imaging Spectrum. RadioGraphics 31:393–408 (PMID: 21415186)
[4] Katabathina VS, Vikram R, Nagar AM, Tamboli P, Menias CO, Prasad SR. (2010) Mesenchymal Neoplasms of the Kidney in Adults: Imaging Spectrum with Radiologic-Pathologic Correlation. Radiographics 30(6):1525-40 (PMID: 21071373)
[5] M. Arias González, A. Iglesias Castañón, B. Nieto Baltar, J. Mañas Uxó, M.C. Ruibal Villanueva y A. Nieto Parga (2014) Tumor fibroso solitario extrapleural: Imagen con RM y su correlación patológica. Radiología 56 (Espec Cong):668
[6] Sung Bin Park, Yang Shin Park, Jeong Kon Kim, Mi Hyun Kim, Young Taik Oh, Kyeong Ah Kim, and Kyoung-Sik Cho (2011) Solitary Fibrous Tumor of the Genitourinary Tract. Roentgenology 196:2, W132-W137 (PMID: 21257853)
[7] Bülent Kurt, Önder Öngürü, Ayhan Özcan, Ali Fuat Çiçek, Şeref Başal, Fatih Örs, Yıldırım Karslıoğlu, Ömer Günhan (2009) Solitary fibrous tumor of kidney: a case report with extensive review of the literature. Gulhane Med J 51(2): 116-121
[8] Abdullah Demirtaş, Volkan Sabur, Hülya Akgün, Emre Can Akınsal, and Deniz Demirci (2013) Solitary Fibrous Tumor of the Kidney: A Case Report. Case Reports in Urology Volume 2013, Article ID 147496, 4 pages (PMID: 23662242)
[9] Gaetano Magro, Vincenzo Cavallaro, Antonietta Torrisi, Maria Lopes, Marcello Dell’Albani, Salvatore Lanzafame (2002) Intrarenal Solitary Fibrous Tumor of the Kidney Report of a Case with Emphasis on the Differential Diagnosis in the Wide Spectrum of Monomorphous Spindle Cell Tumors of the Kidney. Pathol. Res. Pract 198: 37–43 (PMID: 11866209)
[10] Santosh Kumar Mondal, Mamata Guha Mallick, Ranjana Bandyopadhyay, Palash Kumar Mondal (2010) Neurofibroma of kidney: An uncommon neoplasm and diagnostic dilemma with solitary fibrous tumor. J Cancer Res The 6:388-390 (PMID: 21119287)
Case information
| URL: | https://www.eurorad.org/case/12823 |
| DOI: | 10.1594/EURORAD/CASE.12823 |
| ISSN: | 1563-4086 |
License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Figure 2
CT
Contrast-enhanced CT obtained during the corticomedullary phase shows a solid mass in the left kidney, predominantly heterogeneously enhancing, with a small peripheral calcification.
Anatomic pathology
Pathology analysis shows a proliferation of highly cellular spindle cells adopting a storiform pattern.
G. Olmedilla. Department of Pathology. Hospital Universitario Príncipe de Asturias. Alcalá de Henares, Madrid. Spain.
G. Olmedilla. Department of Pathology. Hospital Universitario Príncipe de Asturias. Alcalá de Henares, Madrid. Spain.
Pathology analysis shows a strong immunohistochemical reaction for CD34.
G. Olmedilla. Department of Pathology. Hospital Universitario Príncipe de Asturias. Alcalá de Henares, Madrid. Spain.
G. Olmedilla. Department of Pathology. Hospital Universitario Príncipe de Asturias. Alcalá de Henares, Madrid. Spain.
CT
Contrast-enhanced CT obtained during the corticomedullary phase shows a solid mass in the left kidney, predominantly heterogeneously enhancing, with a small peripheral calcification.
Department of Radiology. Hospital Universitario Príncipe de Asturias. Alcalá de Henares, Madrid. Spain.
Department of Radiology. Hospital Universitario Príncipe de Asturias. Alcalá de Henares, Madrid. Spain.
CT
Coronal enhanced CT shows a well-defined mass arising from the middle region of the left kidney with heterogenous enhancement.
Department of Radiology. Hospital Universitario Príncipe de Asturias. Alcalá de Henares, Madrid. Spain.
Department of Radiology. Hospital Universitario Príncipe de Asturias. Alcalá de Henares, Madrid. Spain.
Sagittal enhanced CT shows well-defined mass arising from the middle region of the left kidney with heterogenous enhancement.
Department of Radiology. Hospital Universitario Príncipe de Asturias. Alcalá de Henares, Madrid. Spain.
Department of Radiology. Hospital Universitario Príncipe de Asturias. Alcalá de Henares, Madrid. Spain.