- Email: [email protected]
Mass-like and extensive secondary tumoral calcinosis in the neck and body of a patient on peritoneal dialysis
Clinical Imaging 37 (2013) 972–975
Contents lists available at ScienceDirect
Clinical Imaging journal homepage: http://www.clinicalimaging.org
Mass-like and extensive secondary tumoral calcinosis in the neck and body of a patient on peritoneal dialysis Katya A. Shpilberg a,⁎, Sarah E. Blowe b, Peter M. Som a a b
Department of Radiology, Mount Sinai Medical Center, New York, NY Department of Pathology, Mount Sinai Medical Center, New York, NY
a r t i c l e
i n f o
Article history: Received 10 July 2012 Received in revised form 21 October 2012 Accepted 17 January 2013 Keywords: Neck Tumoral calcinosis Peritoneal dialysis CT scan
a b s t r a c t We present a case of extensive tumoral calcinosis in a 42-year-old female with end-stage renal disease and secondary hyperparathyroidism on peritoneal dialysis. Periarticular calcified masses demonstrating fluidcalcium levels on computed tomography and containing chalky amorphous calcified material in the absence of neoplastic cells are the salient features of tumoral calcinosis. Although renal failure is the most common cause of secondary tumoral calcinosis, there are few reported cases of this condition occurring in patients on peritoneal dialysis. This case is also unusual due to the widespread and bulky nature of the disease with involvement of the neck and its quick onset and progression. © 2013 Elsevier Inc. All rights reserved.
1. Introduction
2. Case report
Tumoral calcinosis is a pathologic entity characterized by periarticular radiodense dystrophic soft tissue calcifications. Tumoral calcinosis occurs in three clinical settings: as a complication of renal dialysis, in young patients with heritable abnormality of vitamin D metabolism, and sporadically in patients with degenerated or inflamed tissue without metabolic abnormalities [1]. “Metastatic calcifications” is another term for secondary tumoral calcinosis in the setting of metabolic abnormalities such as elevated calcium–phosphorus product in hemodialysis patients or after renal transplantation [2]. Other terms used in the literature for this lesion are uremic tumoral calcinosis, secondary tumoral calcinosis, tumoral calcinosis-like lesion, pseudotumor calcinosis, nonfamilial tumoral calcinosis, and tumoral calcification [3]. This case is presented because of the rapid onset and progression of massive and extensive tumoral calcinosis involving the neck as well as areas of the lower body.
Our patient was a 42-year-old Hispanic female with a 15-year history of end-stage renal disease secondary to uncontrolled hypertension as well as a history of hypothyroidism. Her past surgical history was notable for a renal transplant 13 years ago, which failed 2 years ago. She has been on peritoneal dialysis for the past 8 months. Her glomerular filtration rate was markedly reduced at 2.9 ml/min/ 1.73m2. She had secondary hyperparathyroidism with markedly elevated intact-parathyroid hormone level of 780 pg/ml. Her phosphorus level was elevated at 8 mg/dl, and calcium level was normal at 9.3 mg/dl. Her latest vitamin D level was within normal limits at 45.5 ng/ml. Her medications included darbepoetin alfa, sevelamer, calcitriol, amlodipine and levothyroxin. The patient first noticed subcutaneous “lumps” developing throughout her body approximately 6 months ago, 2 months after starting peritoneal dialysis. The lumps were initially painless and involved the right side of the neck, right shoulder, right elbow, back, right hip, and left foot. They have been gradually but noticeably growing over the course of the past half a year. Approximately 1 month ago, several of these masses became tender, and the patient developed a low-grade fever, prompting her to seek urgent medical attention. Shortly after the initial presentation, she underwent an MRI of the pelvis that showed masses in paraspinal musculature, right gluteus medius muscle, and soft tissues adjacent to the right sacrotuberous ligament and greater tuberosity, all of which were new since the computed tomography (CT) scan of the abdomen and pelvis from 2 1/
Abbreviations: MRI, magnetic resonance imaging; CT, computed tomography; 99TcMDP, technetium-99 conjugated with methylene diphosphonate. ⁎ Corresponding author. The Mount Sinai Medical Center, One Gustave L Levy Place, Department of Radiology Box 1234, New York, NY 10029–6574. Tel.: +1 212 241 7416; fax: +1 212 241 4234. E-mail address: [email protected] (K.A. Shpilberg). 0899-7071/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.clinimag.2013.01.014
K.A. Shpilberg et al. / Clinical Imaging 37 (2013) 972–975
2 years ago. These masses were hypointense on T1-weighted and T2weighted images, and a few of them demonstrated internal layering low signal material (Fig. 1). The differential diagnostic considerations included resolving hematomas, fibrous lesions, vascular lesions/ malformations, and extraarticular pigmented villonodular synovitis. More than a month after the initial presentation, the patient had a CT of the neck, chest, abdomen, and pelvis that revealed extensive lobulated complex periarticular soft tissue masses containing abundant calcifications. The neck CT demonstrated bulky and widespread mass-like calcifications involving the right superior perivertebral muscles as well as the left inferior and posterior perivertebral muscles. Large calcified lesions were also seen at the articulation of the right first and second ribs with the sternum and at the left sternoclavicular joint, both of which were extending into the superior mediastinum (Figs. 2 and 3). Additional lesions in the chest, abdomen and pelvis were located in the right axilla, adjacent to multiple costovertebral junctions, adjacent to the posterior elements of L5 and the sacrum, adjacent to the right ischial tuberosity, and about the right greater trochanter extending between the right gluteus medius and minimus muscles. The lesions in the right neck and adjacent to the sacrum demonstrated layering high-density material likely reflecting milk of calcium. The masses in the neck were new since the prior CT of the cervical spine from 4 years ago, and those in the abdomen and pelvis were new since the prior CT from 2 1/2 years ago. A month after the initial presentation, an incisional biopsy of the tender right lower neck/upper anterior chest wall “mass” was performed. A large amount of purulent material was drained, suggesting that the lesion was most likely an abscess. However, at the base of the fluid collection, there was a large amount of necrotic bone and muscle. The specimen was submitted to pathology and yielded bone, calcified material, and acute and chronic inflammatory cells including histiocytes without evidence of a tumor (Fig. 4). The impression was dystrophic calcifications/tumoral calcinosis, most likely secondary to renal failure, with superimposed infection. The diagnosis of tumoral calcinosis was based on the findings of periarticular extraskeletal deposition of hydroxyapatite crystals surrounded by a granulomatous foreign body reaction.
3. Discussion The most frequent cause of tumoral calcinosis is chronic renal failure [3]. While uremic tumoral calcinosis has been well described in association with hemodialysis, it has rarely been reported in patients undergoing peritoneal dialysis. In one recent study by Chu et al., the incidence of uremic tumoral calcinosis in peritoneal dialysis patients was estimated to be 1.6% (similar to 1.9% in an earlier Japanese study), which is slightly higher than that in hemodialysis patients (0.5%– 1.2%) [4]. In that study by Chu et al., the mean age of onset was 41 years [4], which is similar to our patient who was 42 years old, and most patients had a low normal body mass index (BMI) (average: 20.85 kg/m2) [4], in contrast to our patient who had a BMI of approximately 25. Mean interval from peritoneal dialysis initiation to onset of tumoral calcinosis was 45.3 months [4] in contrast to our patient who became symptomatic within 2 months. The causes of uremia were unrelated to the development of tumoral calcinosis [4]. Uncontrolled hyperphosphatemia with high calcium–phosphorus product (above 60–68 mg2/dl2) was the most common laboratory abnormality [4]; our patient's calcium–phosphorus product was even
Fig. 1. (A–D): Axial T1-weighted (A), sagittal fat-saturated T1-weighted (B), axial fatsaturated T2-weighted (C), and sagittal fat-saturated T2-weighted MRI images of the pelvis demonstrates a mass involving lumbar paraspinal musculature, which is homogeneously hypointense on T1-weighted images, heterogeneous in signal with dependent hypointensity on T2-weighted images, and is consistent with the appearance of tumoral calcinosis.
973
974
K.A. Shpilberg et al. / Clinical Imaging 37 (2013) 972–975
Fig. 2. (A–E): Serial axial wide-windowed CT scans extending from cranial to caudal (A–E) demonstrate the spectrum of appearance of tumoral calcinosis with numerous areas of semisolid and more speckled calcifications involving the cervical paraspinal muscles bilaterally as well as the right parasternal region. Image B demonstrates multiple fluid levels of milk of calcium within one of the neck lesions (red arrows).
more elevated at 74.4. Although uremic tumoral calcinosis is most frequently attributed to hyperparathyroidism (as in the case of our patient), there is evidence that it may occur independently of concomitant hyperparathyroidism [3]. Local factors such as articular or periarticular trauma, hematoma, or inflammation can be a potential “second hit” stimulus in formation of uremic tumoral calcinosis [4]. While it is frequently asymptomatic, particularly in its early stages, uremic tumoral calcinosis is well known to cause pain, disability, and cosmetic problems. In the recent peritoneal dialysis study, the most common manifestation was tenderness, attributed to mass effect of the lesions, followed by limitation of joint range of motion [4]. The shoulders and hands were most frequent sites of involvement, and most patients had multiple lesions [4]. Tumoral calcinosis may emanate from vertebral bodies or posterior elements of the spine and may cause neurological symptoms due to cord or nerve root
compression. In one study, the authors propose that tumoral calcinosis can occur in the spine as a manifestation of degenerative joint disease [1]. Uremic tumoral calcinosis predominates in periarticular soft tissues with preservation of the bone and joint structures [4]. There is tumor-like deposition of dense calcifications, often with a lobular appearance, in the tissues around large joints, which may be associated with smaller masses in the spine and other small joints [5]. The size of calcified masses is typically more than 2 cm around large joints (elbow, shoulder, hip, knee) and greater than 1 cm around small joints (hand, wrist, foot) [4]. These masses may not be easily visualized on plain radiographs [1,5]. CT utilizing bone algorithm is the best imaging modality for characterization of these lesions as it readily reveals absence of cortex and presence of finely speckled or large amorphous, globular internal calcifications. A dense
Fig. 3. (A–C): Serial coronal (A–B) and a sagittal (C) wide-window CT scans further demonstrate the extensive and bulky nature of tumoral calcinosis in the neck.
K.A. Shpilberg et al. / Clinical Imaging 37 (2013) 972–975
Fig. 4. Photomicrograph of material aspirated from one of the lesions demonstrates tumoral calcinosis with lamellar bone trabeculae, dystrophic calcifications, fibrous tissue with histiocytes, fibroblasts, macrophages, and chronic inflammatory cells.
homogeneous calcified mass with interspersed fibrous septae is suggestive of tumoral calcinosis, which can also demonstrate fluidcalcium levels (milk of calcium) on CT [2] (Figs. 2 and 3). On MRI, tumoral calcinosis lesions are distinguished by their hypointensity on both T1- and T2-weighted sequences [5] (Fig. 1). Hyperintensity on T2-weighted imaging is occasionally observed due to increased fluid content [1]. There is increased radiotracer uptake in the periarticular soft tissues surrounding the involved joints on 99Tc–MDP bone scan [4]. At surgery, tumoral calcinosis lesions are commonly cystic and contain a white-to-pale yellow chalky material identified as calcium hydroxyapatite crystals with amorphous calcium carbonate and calcium phosphate. At histopathologic examination, epithelioid elements and multinucleated giant cells surround calcium granules [3] (Fig. 4). The gross finding of chalky material and the histologic examination finding of amorphous, calcified masses in the absence of neoplastic cells confirms the diagnosis [5]. Medical treatment for uremic tumoral calcinosis includes dietary phosphorus restriction, noncalcium phosphate binders, calcimimetics, optimal control of secondary hyperparathyroidism, and intensive hemodialysis with low-calcium dialysate. Medical treatment has variable rates of success. Surgical excision, parathyroidectomy, and renal transplantation are recommended for persistent or refractory uremic tumoral calcinosis [4]. In our case of tumoral calcinosis due to secondary hyperparathyroidism in the setting of end-stage renal
975
disease, all medical treatments had failed, and the patient is currently scheduled to undergo a parathyroidectomy. Uremic tumoral calcinosis can resemble primary tumoral calcinosis radiologically and pathologically. Both entities can present with solitary or multiple painless periarticular soft-tissue calcified lesions, which are typically lobulated and well demarcated and are most often distributed along the extensor surfaces of large joints, most frequently affecting the hips, elbows, and shoulders [3]. However, primary tumoral calcinosis is a rare disease that has a familial tendency without sex predominance, significantly higher incidence in patients of African descent and typical onset during the first two decades of life [3]. The metabolic features of primary tumoral calcinosis consist of normal serum calcium levels and elevated serum phosphate levels [3]. Other conditions that can have radiographic appearance similar to primary and uremic tumoral calcinosis include calcinosis universalis, calcinosis circumscripta, calcific tendonitis, synovial osteochondromatosis, synovial sarcoma, osteosarcoma, myositis ossificans, tophaceous gout, and calcific myonecrosis [3]. 4. Conclusion There are no radiologic or pathologic differences between the lesions of uremic tumoral calcinosis and the lesions of primary tumoral calcinosis. Therefore, diagnosis is based solely on patient demographics, past medical and family history, serum levels of calcium, phosphorus, parathyroid hormone, vitamin D, and creatinine as well as glomerular filtration rate [4]. Based on a literature review, our patient had a typical age and metabolic features for uremic tumoral calcinosis such as hyperparathyroidism (although her BMI and calcium–phosphorus product were higher than the reported average). The strikingly unusual aspects of the case we presented are the rapid onset of symptoms and extensiveness and large size of lesions. References [1] Durant DM, Riley LH, Burger PC, McCarthy EF. Tumoral calcinosis of the spine: a study of 21 cases. Spine 2001;26(15):1673–9. [2] Subhawong TK, Fishman EK, Swart JE, Carrino JA, Attar S, Fayad LM. Soft-tissue masses and masslike conditions: what does CT add to diagnosis and management? Am J Roentgenol 2010;194(6):1559–67. [3] Olsen KM, Chew FS. Tumoral calcinosis: pearls, polemics, and alternative possibilities. Radiographics 2006;26(3):871–85. [4] Chu HY, Chu P, Lin YF, Chou HK, Lin SH. Uremic tumoral calcinosis in patients on peritoneal dialysis: clinical, radiologic and laboratory features. Perit Dial Int 2011;31:430–9. [5] Tuy BE, John TK, Uglialoro AD, Beebe KS, Vives MJ, Patterson FR. Tumoral calcinosis presenting as neck pain and mass lesion of the cervical spine. Am J Orthop 2008;37(11):191–5.
Contents lists available at ScienceDirect
Clinical Imaging journal homepage: http://www.clinicalimaging.org
Mass-like and extensive secondary tumoral calcinosis in the neck and body of a patient on peritoneal dialysis Katya A. Shpilberg a,⁎, Sarah E. Blowe b, Peter M. Som a a b
Department of Radiology, Mount Sinai Medical Center, New York, NY Department of Pathology, Mount Sinai Medical Center, New York, NY
a r t i c l e
i n f o
Article history: Received 10 July 2012 Received in revised form 21 October 2012 Accepted 17 January 2013 Keywords: Neck Tumoral calcinosis Peritoneal dialysis CT scan
a b s t r a c t We present a case of extensive tumoral calcinosis in a 42-year-old female with end-stage renal disease and secondary hyperparathyroidism on peritoneal dialysis. Periarticular calcified masses demonstrating fluidcalcium levels on computed tomography and containing chalky amorphous calcified material in the absence of neoplastic cells are the salient features of tumoral calcinosis. Although renal failure is the most common cause of secondary tumoral calcinosis, there are few reported cases of this condition occurring in patients on peritoneal dialysis. This case is also unusual due to the widespread and bulky nature of the disease with involvement of the neck and its quick onset and progression. © 2013 Elsevier Inc. All rights reserved.
1. Introduction
2. Case report
Tumoral calcinosis is a pathologic entity characterized by periarticular radiodense dystrophic soft tissue calcifications. Tumoral calcinosis occurs in three clinical settings: as a complication of renal dialysis, in young patients with heritable abnormality of vitamin D metabolism, and sporadically in patients with degenerated or inflamed tissue without metabolic abnormalities [1]. “Metastatic calcifications” is another term for secondary tumoral calcinosis in the setting of metabolic abnormalities such as elevated calcium–phosphorus product in hemodialysis patients or after renal transplantation [2]. Other terms used in the literature for this lesion are uremic tumoral calcinosis, secondary tumoral calcinosis, tumoral calcinosis-like lesion, pseudotumor calcinosis, nonfamilial tumoral calcinosis, and tumoral calcification [3]. This case is presented because of the rapid onset and progression of massive and extensive tumoral calcinosis involving the neck as well as areas of the lower body.
Our patient was a 42-year-old Hispanic female with a 15-year history of end-stage renal disease secondary to uncontrolled hypertension as well as a history of hypothyroidism. Her past surgical history was notable for a renal transplant 13 years ago, which failed 2 years ago. She has been on peritoneal dialysis for the past 8 months. Her glomerular filtration rate was markedly reduced at 2.9 ml/min/ 1.73m2. She had secondary hyperparathyroidism with markedly elevated intact-parathyroid hormone level of 780 pg/ml. Her phosphorus level was elevated at 8 mg/dl, and calcium level was normal at 9.3 mg/dl. Her latest vitamin D level was within normal limits at 45.5 ng/ml. Her medications included darbepoetin alfa, sevelamer, calcitriol, amlodipine and levothyroxin. The patient first noticed subcutaneous “lumps” developing throughout her body approximately 6 months ago, 2 months after starting peritoneal dialysis. The lumps were initially painless and involved the right side of the neck, right shoulder, right elbow, back, right hip, and left foot. They have been gradually but noticeably growing over the course of the past half a year. Approximately 1 month ago, several of these masses became tender, and the patient developed a low-grade fever, prompting her to seek urgent medical attention. Shortly after the initial presentation, she underwent an MRI of the pelvis that showed masses in paraspinal musculature, right gluteus medius muscle, and soft tissues adjacent to the right sacrotuberous ligament and greater tuberosity, all of which were new since the computed tomography (CT) scan of the abdomen and pelvis from 2 1/
Abbreviations: MRI, magnetic resonance imaging; CT, computed tomography; 99TcMDP, technetium-99 conjugated with methylene diphosphonate. ⁎ Corresponding author. The Mount Sinai Medical Center, One Gustave L Levy Place, Department of Radiology Box 1234, New York, NY 10029–6574. Tel.: +1 212 241 7416; fax: +1 212 241 4234. E-mail address: [email protected] (K.A. Shpilberg). 0899-7071/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.clinimag.2013.01.014
K.A. Shpilberg et al. / Clinical Imaging 37 (2013) 972–975
2 years ago. These masses were hypointense on T1-weighted and T2weighted images, and a few of them demonstrated internal layering low signal material (Fig. 1). The differential diagnostic considerations included resolving hematomas, fibrous lesions, vascular lesions/ malformations, and extraarticular pigmented villonodular synovitis. More than a month after the initial presentation, the patient had a CT of the neck, chest, abdomen, and pelvis that revealed extensive lobulated complex periarticular soft tissue masses containing abundant calcifications. The neck CT demonstrated bulky and widespread mass-like calcifications involving the right superior perivertebral muscles as well as the left inferior and posterior perivertebral muscles. Large calcified lesions were also seen at the articulation of the right first and second ribs with the sternum and at the left sternoclavicular joint, both of which were extending into the superior mediastinum (Figs. 2 and 3). Additional lesions in the chest, abdomen and pelvis were located in the right axilla, adjacent to multiple costovertebral junctions, adjacent to the posterior elements of L5 and the sacrum, adjacent to the right ischial tuberosity, and about the right greater trochanter extending between the right gluteus medius and minimus muscles. The lesions in the right neck and adjacent to the sacrum demonstrated layering high-density material likely reflecting milk of calcium. The masses in the neck were new since the prior CT of the cervical spine from 4 years ago, and those in the abdomen and pelvis were new since the prior CT from 2 1/2 years ago. A month after the initial presentation, an incisional biopsy of the tender right lower neck/upper anterior chest wall “mass” was performed. A large amount of purulent material was drained, suggesting that the lesion was most likely an abscess. However, at the base of the fluid collection, there was a large amount of necrotic bone and muscle. The specimen was submitted to pathology and yielded bone, calcified material, and acute and chronic inflammatory cells including histiocytes without evidence of a tumor (Fig. 4). The impression was dystrophic calcifications/tumoral calcinosis, most likely secondary to renal failure, with superimposed infection. The diagnosis of tumoral calcinosis was based on the findings of periarticular extraskeletal deposition of hydroxyapatite crystals surrounded by a granulomatous foreign body reaction.
3. Discussion The most frequent cause of tumoral calcinosis is chronic renal failure [3]. While uremic tumoral calcinosis has been well described in association with hemodialysis, it has rarely been reported in patients undergoing peritoneal dialysis. In one recent study by Chu et al., the incidence of uremic tumoral calcinosis in peritoneal dialysis patients was estimated to be 1.6% (similar to 1.9% in an earlier Japanese study), which is slightly higher than that in hemodialysis patients (0.5%– 1.2%) [4]. In that study by Chu et al., the mean age of onset was 41 years [4], which is similar to our patient who was 42 years old, and most patients had a low normal body mass index (BMI) (average: 20.85 kg/m2) [4], in contrast to our patient who had a BMI of approximately 25. Mean interval from peritoneal dialysis initiation to onset of tumoral calcinosis was 45.3 months [4] in contrast to our patient who became symptomatic within 2 months. The causes of uremia were unrelated to the development of tumoral calcinosis [4]. Uncontrolled hyperphosphatemia with high calcium–phosphorus product (above 60–68 mg2/dl2) was the most common laboratory abnormality [4]; our patient's calcium–phosphorus product was even
Fig. 1. (A–D): Axial T1-weighted (A), sagittal fat-saturated T1-weighted (B), axial fatsaturated T2-weighted (C), and sagittal fat-saturated T2-weighted MRI images of the pelvis demonstrates a mass involving lumbar paraspinal musculature, which is homogeneously hypointense on T1-weighted images, heterogeneous in signal with dependent hypointensity on T2-weighted images, and is consistent with the appearance of tumoral calcinosis.
973
974
K.A. Shpilberg et al. / Clinical Imaging 37 (2013) 972–975
Fig. 2. (A–E): Serial axial wide-windowed CT scans extending from cranial to caudal (A–E) demonstrate the spectrum of appearance of tumoral calcinosis with numerous areas of semisolid and more speckled calcifications involving the cervical paraspinal muscles bilaterally as well as the right parasternal region. Image B demonstrates multiple fluid levels of milk of calcium within one of the neck lesions (red arrows).
more elevated at 74.4. Although uremic tumoral calcinosis is most frequently attributed to hyperparathyroidism (as in the case of our patient), there is evidence that it may occur independently of concomitant hyperparathyroidism [3]. Local factors such as articular or periarticular trauma, hematoma, or inflammation can be a potential “second hit” stimulus in formation of uremic tumoral calcinosis [4]. While it is frequently asymptomatic, particularly in its early stages, uremic tumoral calcinosis is well known to cause pain, disability, and cosmetic problems. In the recent peritoneal dialysis study, the most common manifestation was tenderness, attributed to mass effect of the lesions, followed by limitation of joint range of motion [4]. The shoulders and hands were most frequent sites of involvement, and most patients had multiple lesions [4]. Tumoral calcinosis may emanate from vertebral bodies or posterior elements of the spine and may cause neurological symptoms due to cord or nerve root
compression. In one study, the authors propose that tumoral calcinosis can occur in the spine as a manifestation of degenerative joint disease [1]. Uremic tumoral calcinosis predominates in periarticular soft tissues with preservation of the bone and joint structures [4]. There is tumor-like deposition of dense calcifications, often with a lobular appearance, in the tissues around large joints, which may be associated with smaller masses in the spine and other small joints [5]. The size of calcified masses is typically more than 2 cm around large joints (elbow, shoulder, hip, knee) and greater than 1 cm around small joints (hand, wrist, foot) [4]. These masses may not be easily visualized on plain radiographs [1,5]. CT utilizing bone algorithm is the best imaging modality for characterization of these lesions as it readily reveals absence of cortex and presence of finely speckled or large amorphous, globular internal calcifications. A dense
Fig. 3. (A–C): Serial coronal (A–B) and a sagittal (C) wide-window CT scans further demonstrate the extensive and bulky nature of tumoral calcinosis in the neck.
K.A. Shpilberg et al. / Clinical Imaging 37 (2013) 972–975
Fig. 4. Photomicrograph of material aspirated from one of the lesions demonstrates tumoral calcinosis with lamellar bone trabeculae, dystrophic calcifications, fibrous tissue with histiocytes, fibroblasts, macrophages, and chronic inflammatory cells.
homogeneous calcified mass with interspersed fibrous septae is suggestive of tumoral calcinosis, which can also demonstrate fluidcalcium levels (milk of calcium) on CT [2] (Figs. 2 and 3). On MRI, tumoral calcinosis lesions are distinguished by their hypointensity on both T1- and T2-weighted sequences [5] (Fig. 1). Hyperintensity on T2-weighted imaging is occasionally observed due to increased fluid content [1]. There is increased radiotracer uptake in the periarticular soft tissues surrounding the involved joints on 99Tc–MDP bone scan [4]. At surgery, tumoral calcinosis lesions are commonly cystic and contain a white-to-pale yellow chalky material identified as calcium hydroxyapatite crystals with amorphous calcium carbonate and calcium phosphate. At histopathologic examination, epithelioid elements and multinucleated giant cells surround calcium granules [3] (Fig. 4). The gross finding of chalky material and the histologic examination finding of amorphous, calcified masses in the absence of neoplastic cells confirms the diagnosis [5]. Medical treatment for uremic tumoral calcinosis includes dietary phosphorus restriction, noncalcium phosphate binders, calcimimetics, optimal control of secondary hyperparathyroidism, and intensive hemodialysis with low-calcium dialysate. Medical treatment has variable rates of success. Surgical excision, parathyroidectomy, and renal transplantation are recommended for persistent or refractory uremic tumoral calcinosis [4]. In our case of tumoral calcinosis due to secondary hyperparathyroidism in the setting of end-stage renal
975
disease, all medical treatments had failed, and the patient is currently scheduled to undergo a parathyroidectomy. Uremic tumoral calcinosis can resemble primary tumoral calcinosis radiologically and pathologically. Both entities can present with solitary or multiple painless periarticular soft-tissue calcified lesions, which are typically lobulated and well demarcated and are most often distributed along the extensor surfaces of large joints, most frequently affecting the hips, elbows, and shoulders [3]. However, primary tumoral calcinosis is a rare disease that has a familial tendency without sex predominance, significantly higher incidence in patients of African descent and typical onset during the first two decades of life [3]. The metabolic features of primary tumoral calcinosis consist of normal serum calcium levels and elevated serum phosphate levels [3]. Other conditions that can have radiographic appearance similar to primary and uremic tumoral calcinosis include calcinosis universalis, calcinosis circumscripta, calcific tendonitis, synovial osteochondromatosis, synovial sarcoma, osteosarcoma, myositis ossificans, tophaceous gout, and calcific myonecrosis [3]. 4. Conclusion There are no radiologic or pathologic differences between the lesions of uremic tumoral calcinosis and the lesions of primary tumoral calcinosis. Therefore, diagnosis is based solely on patient demographics, past medical and family history, serum levels of calcium, phosphorus, parathyroid hormone, vitamin D, and creatinine as well as glomerular filtration rate [4]. Based on a literature review, our patient had a typical age and metabolic features for uremic tumoral calcinosis such as hyperparathyroidism (although her BMI and calcium–phosphorus product were higher than the reported average). The strikingly unusual aspects of the case we presented are the rapid onset of symptoms and extensiveness and large size of lesions. References [1] Durant DM, Riley LH, Burger PC, McCarthy EF. Tumoral calcinosis of the spine: a study of 21 cases. Spine 2001;26(15):1673–9. [2] Subhawong TK, Fishman EK, Swart JE, Carrino JA, Attar S, Fayad LM. Soft-tissue masses and masslike conditions: what does CT add to diagnosis and management? Am J Roentgenol 2010;194(6):1559–67. [3] Olsen KM, Chew FS. Tumoral calcinosis: pearls, polemics, and alternative possibilities. Radiographics 2006;26(3):871–85. [4] Chu HY, Chu P, Lin YF, Chou HK, Lin SH. Uremic tumoral calcinosis in patients on peritoneal dialysis: clinical, radiologic and laboratory features. Perit Dial Int 2011;31:430–9. [5] Tuy BE, John TK, Uglialoro AD, Beebe KS, Vives MJ, Patterson FR. Tumoral calcinosis presenting as neck pain and mass lesion of the cervical spine. Am J Orthop 2008;37(11):191–5.