Idiopathic Sporadic Tumoral Calcinosis of the Hip: Successful Oral Bisphosphonate Therapy

ObjectiveTo report the case of a woman with idiopathic sporadic tumoral calcinosis treated successfully with orally administered bisphosphonates.MethodsWe report the clinical, laboratory, and imaging findings and describe the clinical course of tumoral calcinosis. The literature was reviewed for the pathophysiologic features and strategies for treatment of tumoral calcinosis. In addition, we specifically reviewed the use of bisphosphonates in tumoral calcinosis and the possible pharmacologic basis for the therapeutic benefit.ResultsA 45-year-old woman presented with a 6-week history of left-sided pain in the hip in conjunction with stiffness after a trivial fall 4 weeks before the onset of symptoms. The findings on conventional radiology of the hip joint were consistent with tumoral calcinosis of the left hip. The biochemical profile of the patient was unremarkable. Oral treatment with alendronate, 70 mg once a week, yielded alleviation of symptoms within 12 weeks. Radiology of the left hip repeated after a period of 15 months revealed notable regression of the calcified lesion.ConclusionBisphosphonate therapy may be considered as an alternative to surgical treatment in patients with idiopathic sporadic tumoral calcinosis. (Endocr Pract. 2007;13:182-186)     

Hyperphosphatemic tumoral calcinosis

Tumoral calcinosis is a rare syndrome characterized by progressively growing and painless masses of calcium phosphate deposits within periarticular areas. Biochemical findings are normal except for an association with hyperphosphatemia. This report describes hyperphosphatemic tumoral calcinosis in a 22-year-old man who had been operated on five times in 5 years because of painless extremity swellings.     

Cytologic diagnosis of tumoral calcinosis: a case report

A 55-year-old male with end-stage renal disease on hemodialysis presented with neck pain of 1 year's duration. A computed tomography (CT) scan was performed as part of his workup, and a posterior cervical neck mass was detected. CT-guided fine needle aspiration was performed with an immediate cytologic interpretation of tumoral calcinosis. On air-dried Diff-Quik and alcohol-fixed Papanicolaou-stained smears, the specimen demonstrated coarse-to-fine calcific debris. A final diagnosis of tumoral calcinosis was rendered. A literature search revealed that this diagnosis is rarely made by touch imprint cytology of core needle biopsy and/or needle aspiration cytology, although it can be a relatively easy and straightforward diagnosis.     

Polypeptide GalNAc-transferase T3 and familial tumoral calcinosis. Secretion of fibroblast growth factor 23 requires O-glycosylation

Mutations in the gene encoding the glycosyltransferase polypeptide GalNAc-T3, which is involved in initiation of O-glycosylation, were recently identified as a cause of the rare autosomal recessive metabolic disorder familial tumoral calcinosis (OMIM 211900). Familial tumoral calcinosis is associated with hyperphosphatemia and massive ectopic calcifications. Here, we demonstrate that the secretion of the phosphaturic factor fibroblast growth factor 23 (FGF23) requires O-glycosylation, and that GalNAc-T3 selectively directs O-glycosylation in a subtilisin-like proprotein convertase recognition sequence motif, which blocks processing of FGF23. The study suggests a novel posttranslational regulatory model of FGF23 involving competing O-glycosylation and protease processing to produce intact FGF23.     

Tumoral Calcinosis—an Unrecognized Disease

Twenty-six cases of tumoral calcinosis are reported from Kenya. The disease, frequently misdiagnosed, is of unknown origin. It presents as calcified tumours, usually around the hips and buttocks, in muscle and subcutaneous tissue. The tumours are partly solid, partly multiloculated cysts which contain a chalky fluid. They may grow rapidly or very slowly, and are found in children and adults. Both sexes are affected and there is no obvious tribal or geographical localization.     

Familial tumoral calcinosis and the role of O-glycosylation in the maintenance of phosphate homeostasis

Familial tumoral calcinosis refers to a group of disorders inherited in an autosomal recessive fashion. Hyperphosphatemic tumoral calcinosis is characterized by increased re-absorption of phosphate through the renal proximal tubule, resulting in elevated phosphate concentration and deposition of calcified deposits in cutaneous and subcutaneous tissues, as well as, occasionally, in visceral organs. The disease was found to result from mutations in at least 3 genes: GALNT3, encoding a glycosyltransferase termed ppGalNacT3, FGF23 encoding a potent phosphaturic protein, and KL encoding Klotho. Recent data showed that ppGalNacT3 mediates O-glycosylation of FGF23, thereby allowing for its secretion and possibly protecting it from proteolysis-mediated inactivation. Klotho was found to serve as a co-receptor for FGF23, thereby integrating the genetic data into a single physiological system. The elucidation of the molecular basis of HFTC shed new light upon the mechanisms regulating phosphate homeostasis, suggesting innovative therapeutic strategies for the management of hyperphosphatemia in common acquired conditions such as chronic renal failure.     

Tratamiento de los adenomas hipofisarios clínicamente no funcionantes

Clinically nonfunctioning adenomas are the most frequent pituitary macroadenomas in adults. These tumors are characterized by the absence of detectable hormonal hypersecretion and are diagnosed when compression symptoms or hormonal deficiencies occur. The treatment of choice of macroadenomas is surgery, but tumoral resection is often incomplete or the patient develops tumoral recurrence. Medical therapy has been shown to produce modest tumoral reduction in some patients. Postoperative irradiation should be considered in patients with large tumoral remnants or enlargement of remnants during follow-up. Stereotactic radiotherapy has been developed to diminish the long-term complications of radiotherapy. Microadenomas tend to remain small and surveillance alone is recommended. The present article reviews the results of medical, surgical and radiation treatments.     

FGF23 and disorders of phosphate homeostasis

It is well known that fibroblast growth factor (FGF) family members are associated with embryonic development and are critical for basic metabolic functions. This review will focus upon fibroblast growth factor-23 (FGF23) and its roles in disorders associated with phosphate handling. The discovery that mutations in FGF23 were responsible for the isolated renal phosphate wasting disorder autosomal dominant hypophosphatemic rickets (ADHR) has ascribed novel functions to the FGF family. FGF23 circulates in the bloodstream, and animal models demonstrate that FGF23 controls phosphate and Vitamin D homeostasis through the regulation of specific renal proteins. The ADHR mutations in FGF23 produce a protein species less susceptible to proteolytic processing. X-linked hypophosphatemic rickets (XLH), tumor-induced osteomalacia (TIO), and fibrous dysplasia of bone (FD) are disorders involving phosphate homeostasis that share phenotypes with ADHR, indicating that FGF23 may be a common denominator for the pathophysiology of these syndromes. Our understanding of FGF23 will help to develop novel therapies for phosphate wasting disorders, as well as for disorders of increased serum phosphate, such as tumoral calcinosis, a rare disorder, and renal failure, a common disorder.     

Osteo-renal regulation of systemic phosphate metabolism

Impaired kidney function and subsequent skeletal responses play a critical role in disrupting phosphate balance in chronic kidney disease (CKD) patients with mineral and bone disorder (CKD-MBD). In patients with CKD-MBD, the inability of the kidney to maintain normal mineral ion balance affects bone remodeling to induce skeletal fracture and extraskeletal vascular calcification. In physiological conditions, bone-derived fibroblast growth factor 23 (FGF23) acts on the kidney to reduce serum phosphate and 1,25-dihydroxyvitamin D levels. In humans, increased bioactivity of FGF23 leads to increased urinary phosphate excretion, which induces hypophosphatemic diseases (e.g., rickets/osteomalacia). However, reduced FGF23 activity is associated with hyperphosphatemic diseases (e.g., tumoral calcinosis). In patients with CKD, high serum levels of FGF23 fail to reduce serum phosphate levels and lead to numerous complications, including vascular calcification, one of the important determinants of mortality of CKD-MBD patients. Of particular significance, molecular, biochemical and morphological changes in patients with CKD-MBD are mostly due to osteo-renal dysregulation of mineral ion metabolism. Furthermore, hyperphosphatemia can partly contribute to the development of secondary hyperparathyroidism in patients with CKD-MBD. Relatively new pharmacological agents including sevelamer hydrochloride, calcitriol analogs and cinacalcet hydrochloride are used either alone, or in combination, to minimize hyperphosphatemia and hyperparathyroidism associated complications to improve morbidity and mortality of CKD-MBD patients. This article will briefly summarize how osteo-renal miscommunication can induce phosphate toxicity, resulting in extensive tissue injuries.     

Aspiration cytodiagnosis of the breast with abundant acellular calcific material indicative of soft tissue calcinosis (a study of 3 cases)

Calcific deposits in soft tissue are rare and may clinically resemble a tumour. It seems feasible, therefore, to investigate them by the non-invasive technique of fine needle aspiration cytology (FNAC). In this study three cases with extensive accumulation of acellular calcific material in the breast are described in which FNAC was indicative of soft tissue calcinosis. In all cases routine mammogram had shown a partially cystic opacity. All other investigations were normal and no significant family or medical history was present. Cytopreparations in all cases showed only abundant acellular calcium. The patients had no further treatment and on follow up were clinically well with no changes. The cases are interesting, since the cytohistological findings in the aspirate sample appeared to be strongly indicative of soft tissue calcinosis.     

Calcinosis cutis in chronic renal failure diagnosed by fine needle aspiration. A case report

BACKGROUND: Deposition of calcium salts in the skin and subcutis, referred to as calcinosis cutis, is a common complication in patients with end-stage renal disease. The lesion can present as a mass and is amenable to fine needle aspiration (FNA). CASE: A 48-year-old man undergoing hemodialysis following a failed renal transplant presented with a 1.5-cm neck nodule. A diagnosis of calcinosis cutis was made following FNA, which obtained semiliquid, chalky material. CONCLUSION: In cytologic preparations, deposits of calcium salts can be both amorphous and refractile on Diff-Quik and Papanicolaou stain. However, the material may not be birefringent with these stains. Alizarin red S stain for calcium will permit demonstration of the characteristic birefringence.     

A systematic study of site-specific GalNAc-type O-glycosylation modulating proprotein convertase processing

Site-specific GalNAc-type O-glycosylation is emerging as an important co-regulator of proprotein convertase (PC) processing of proteins. PC processing is crucial in regulating many fundamental biological pathways and O-glycans in or immediately adjacent to processing sites may affect recognition and function of PCs. Thus, we previously demonstrated that deficiency in site-specific O-glycosylation in a PC site of the fibroblast growth factor, FGF23, resulted in marked reduction in secretion of active unprocessed FGF23, which cause familial tumoral calcinosis and hyperostosis hyperphosphatemia. GalNAc-type O-glycosylation is found on serine and threonine amino acids and up to 20 distinct polypeptide GalNAc transferases catalyze the first addition of GalNAc to proteins making this step the most complex and differentially regulated steps in protein glycosylation. There is no reliable prediction model for O-glycosylation especially of isolated sites, but serine and to a lesser extent threonine residues are frequently found adjacent to PC processing sites. In the present study we used in vitro enzyme assays and ex vivo cell models to systematically address the boundaries of the region within site-specific O-glycosylation affect PC processing. The results demonstrate that O-glycans within at least ±3 residues of the RXXR furin cleavage site may affect PC processing suggesting that site-specific O-glycosylation is a major co-regulator of PC processing.     

A deleterious mutation in SAMD9 causes normophosphatemic familial tumoral calcinosis

Familial tumoral calcinosis (FTC) is a rare autosomal recessive disorder characterized by the progressive deposition of calcified masses in cutaneous and subcutaneous tissues, which results in painful ulcerative lesions and severe skin and bone infections. Two major types of FTC have been recognized: hyperphosphatemic FTC (HFTC) and normophosphatemic FTC (NFTC). HFTC was recently shown to result from mutations in two different genes: GALNT3, which codes for a glycosyltransferase, and FGF23, which codes for a potent phosphaturic protein. To determine the molecular cause of NFTC, we performed homozygosity mapping in five affected families of Jewish Yemenite origin and mapped NFTC to 7q21-7q21.3. Mutation analysis revealed a homozygous mutation in the SAMD9 gene (K1495E), which was found to segregate with the disease in all families and to interfere with the protein expression. Our data suggest that SAMD9 is involved in the regulation of extraosseous calcification, a process of considerable importance in a wide range of diseases as common as atherosclerosis and autoimmune disorders.     

Single-cell mtDNA heteroplasmy in colorectal cancer

Human mitochondria can be genetically distinct within the same individual, a phenomenon known as heteroplasmy. In cancer, this phenomenon seems exacerbated, and most mitochondrial mutations seem to be heteroplasmic. How this genetic variation is arranged within and among normal and tumor cells is not well understood. To address this question, here we sequenced single-cell mitochondrial genomes from multiple normal and tumoral locations in four colorectal cancer patients. Our results suggest that single cells, both normal and tumoral, can carry various mitochondrial haplotypes. Remarkably, this intra-cell heteroplasmy can arise before tumor development and be maintained afterward in specific tumoral cell subpopulations. At least in the colorectal patients studied here, the somatic mutations in the single-cells do not seem to have a prominent role in tumorigenesis.     

GALNT3, a gene associated with hyperphosphatemic familial tumoral calcinosis, is transcriptionally regulated by extracellular phosphate and modulates matrix metalloproteinase activity

GALNT3 encodes UDP-N-acetyl-alpha-d-galactosamine: polypeptide N-acetylgalactosaminyl-transferarase 3 (ppGalNacT3), a glycosyltransferase which has been suggested to prevent proteolysis of FGF23, a potent phosphaturic protein. Accordingly, loss-of-function mutations in GALNT3 cause hyperphosphatemic familial tumoral calcinosis (HFTC), a rare autosomal recessive disorder manifesting with increased kidney reabsorption of phosphate, resulting in severe hyperphosphatemia and widespread ectopic calcifications. Although these findings definitely attribute a role to ppGalNacT3 in the regulation of phosphate homeostasis, little is currently known about the factors regulating GALNT3 expression. In addition, the effect of decreased GALNT3 expression in peripheral tissues has not been explored so far. In the present study, we demonstrate that GALNT3 expression is under the regulation of a number of factors known to be associated with phosphate homeostasis, including inorganic phosphate itself, calcium and 1,25-dihydroxyvitamin D(3). In addition, we show that decreased GALNT3 expression in human skin fibroblasts leads to increased expression of FGF7 and of matrix metalloproteinases, which have been previously implicated in the pathogenesis of ectopic calcification. Thus, the present data suggest that ppGalNacT3 may play a role in peripheral tissues of potential relevance to the pathogenesis of disorders of phosphate metabolism.     

Sterile α Motif Domain Containing 9 Is a Novel Cellular Interacting Partner to Low-Risk Type Human Papillomavirus E6 Proteins

Low-risk type human papillomavirus (HPV) 6 and 11 infection causes recurrent respiratory papillomatosis (RRP) and genital warts. RRP is the most common benign tumor of the larynx in children with frequent relapses. Repeated surgeries are often needed to improve vocal function and prevent life-threatening respiratory obstruction. Currently, there are no effective treatments available to completely eliminate these diseases, largely due to limited knowledge regarding their viral molecular pathogenesis. HPV E6 proteins contribute to cell immortalization by interacting with a variety of cellular proteins, which have been well studied for the high-risk type HPVs related to cancer progression. However, the functions of low-risk HPV E6 proteins are largely unknown. In this study, we report GST-pulldown coupled mass spectrometry analysis with low-risk HPV E6 proteins that identified sterile alpha motif domain containing 9 (SAMD9) as a novel interacting partner. We then confirmed the interaction between HPV-E6 and SAMD9 using co-immunoprecipitation, proximity ligation assay, and confocal immunofluorescence staining. The SAMD9 gene is down-regulated in a variety of neoplasms and deleteriously mutated in normophosphatemic familial tumoral calcinosis. Interestingly, SAMD9 also has antiviral functions against poxvirus. Our study adds to the limited knowledge of the molecular properties of low-risk HPVs and describes new potential functions for the low-risk HPV E6 protein.     

Calcinosis and metastatic calcification due to vitamin D intoxication. A case report and review.

Vitamin D, a fat-soluble vitamin, can be associated with significant morbidity when prescribed in large doses. We describe a hypoparathyroid patient with vitamin D intoxication who developed painful periarticular calcinosis, nephrocalcinosis with hypertension and chronic renal failure in addition to band keratopathy and hearing loss. He was treated with combination therapy including prednisone, phosphate-binding antacid, phenytoin and disodium etidronate. After 20 months of follow-up there was a significant reduction of periarticular calcinosis, but no improvement in renal function, band keratopathy or hearing loss and possible calcification of the ossicles. The clinicopathologic features of metastatic calcification and the various treatment modalities are reviewed.     

Vitamin D receptor levels in colorectal cancer. Possible role of BsmI polymorphism

A high expression of vitamin D receptor (VDR) in colorectal cancer (CRC) tumoral tissue has been related to a good prognosis and it has been proposed that it could be a good biological marker of CRC progression. Nevertheless, there are no previous studies that compare the VDR expression in tumoral towards normal tissue of the same CRC patient in relation to VDR BsmI genotype. We collected normal and tumoral tissue samples, as well as blood samples, from CRC patients (n=170) and controls (n=122). VDR genotyping was performed and BsmI homozygous patients were selected (CRC=50, Cont=32). VDR mRNA and protein levels were analyzed. We also measured 25-Hydroxyvitamin D serum levels. We found no differences in the polymorphism distribution in tumoral versus normal tissue (control: BB=15.7%, bb=41.3%, Bb=43%; CRC: BB=14.2%, bb=41.9%, Bb=43.9%). Furthermore, VDR levels decreased in colonic cancer tissue (mean: 3.03) versus normal mucosa (11.62) from the same patient (p<0.001), but this decrease was similar in both genotypes. There were differences in 25-Hydroxyvitamin D(3) levels between the CRC and the control group (CRC=8.65 ng/ml, Cont=18.15 ng/ml). In conclusion, we found a decrease in VDR levels in tumoral compared with normal mucosa from the same patient. This difference is independent of the BsmI polymorphism.     

Long-acting somatostatin analogues in pancreatic islet cell carcinoma

In secreting islet cell carcinoma, the long-acting somatostatin analogue, Sandostatin, reduces symptoms of endocrine secretion both by inhibiting peptide secretion and by acting on the target organs. It could be used during the initial evaluation of patients with such tumors and thereafter when the tumor cannot be found or is metastatic. Its efficacy depends upon the tumor type and probably the presence of somatostatin receptors on the tumoral cells. It could decrease with time, especially in VIPomas. Side effects are few and usually mild. Hypoglycemia attacks in insulinoma could be worsened during treatment by the complete inhibition of hyperglycemic hormones. The inhibition of tumoral growth, based on animal models, appears infrequent in clinical practice.     

Nestin expression associates with poor prognosis and triple negative phenotype in locally advanced (T4) breast cancer

Nestin, an intermediate filament protein, has traditionally been noted for its importance as a neural stem cell marker. However, in recent years, expression of nestin has shown to be associated with general proliferation of progenitor cell populations within neoplasms. There is no reported study addressing nestin expression in T4 breast cancer patients. Thus, the aim of the present study was to investigate, through immunohistochemistry, the expression and distribution of nestin in T4 breast cancer, in order to determine its association with clinical and pathological parameters as well as with patients' outcome. Nestin was detectable in tumoral cells and in endothelial cells of blood microvessels, and it is significantly expressed in triple-negative and in inflammatory breast cancer (IBC) subgroups of T4 breast tumours. The Kaplan-Meier analysis showed that the presence of nestin in tumoral cells significantly predicted poor prognosis at 5-years survival (P=0.02) and with borderline significance at 10-years of survival (P=0.05) in T4 breast cancer patients. On the basis of these observations, we speculate that nestin expression may characterize tumours with an aggressive clinical behavior, suggesting that the presence of nestin in tumoral cells and vessels may be considered an important factor that leads to a poor prognosis. Further studies are awaited to define the biological role of nestin in the etiology of these subgroups of breast cancers.