Craniofacial hemangiopericytoma associated with oncogenic osteomalacia: case report

Intracranial phosphaturic mesenchymal tumors. A case report and review of literature

Most osteomalacia-inducing tumors (OITs) are phosphaturic mesenchymal tumors (PMTs) that secrete fibroblast growth factor 23 (FGF23). These tumors usually occur in the bone and soft tissues, and intracranial OITs are rare. Therefore, intracranial OIT is difficult to diagnose and treat. This paper presents a case of intracranial OIT and shows a review of previous cases. A 45-year-old man underwent nasal cavity biopsy and treatment with active vitamin D₃ and neutral phosphate for hypophosphatemia. Amplification of FGF23 mRNA level within the tumor was detected. Subsequently, the surgical specimen was diagnosed with a PMT and was considered the cause of the patient's osteomalacia. The patient was referred to a neurosurgery department for the excision of the intracranial tumor extending to the nasal cavity. After tumor removal, the serum levels of FGF23 and phosphorus were normalized as compared to preoperative those. The patient remains disease-free, without additional treatment, approximately 10 years after surgery, with no tumor recurrence. As per the literature, intracranial OITs usually occur in patients aged 8-69 years. Bone and muscle pain are major complaints. Approximately 60% of the patients reported previously had symptoms because of intracranial tumors. In some cases, it took several years to diagnose OIT after the onset of the osteomalacia symptoms. Laboratory data in such cases show hypophosphatemia and elevated FGF23 levels. Because FGF23 levels are associated with the severity of osteomalacia symptoms, total tumor resection is recommended. PMT and hemangiopericytoma (HPC) are histologically similar, but on immunochemistry, PMT is negative for signal transducer and activator of transcription 6 (STAT6), whereas HPC is positive. FGF23 amplification is seen in PMTs but not in HPCs. Therefore, the analysis of FGF23 and STAT6 was helpful in distinguishing PMTs from HPCs. In cases of hypophosphatemia and osteomalacia without a history of metabolic, renal, or malabsorptive diseases, the possibility of oncogenic osteomalacia should be considered.

Successful Treatment of Tumor-Induced Osteomalacia by Multidisciplinary Therapy with Radiation to Intracranial Fibromyxoid Tumor

Background

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by protein fibroblast-growth-factor-23 (FGF-23) secreting tumors. Complete tumor resection is the current standard of care for TIO; however, some patients may develop tumor recurrence. Due to the rarity of this paraneoplastic syndrome, the role of radiotherapy is unclear. This case is worth reporting because it adds to our knowledge some insights about the potential role of radiotherapy in this rare condition. Case Presentation. After multidisciplinary consultation, in July 2015, postoperative adjuvant radiotherapy was offered to a 52-year-old man with a multiple recurrent ossifying fibromyxoid tumor in the right frontal sinus causing TIO. The patient had a history of multiple bone fractures and pain since more than 20 years. The tumor had been removed in 2003 for the first time. Subsequent endoscopic resections of the tumor had been performed for recurrences of TIO in May 2012, October 2013, and July 2015. Starting from October 2015, external beam radiotherapy was delivered with a volumetric modulated arc technique to the tumor bed with a daily dose of 2 Gy up to a total dose of 60 Gy. After five years from treatment, the patient is free from local tumor relapse, TIO progression, and radiation-induced side effects.

Conclusions

Radiotherapy may provide long-term TIO remission and tumor control, thus being a treatment option in cases where surgery is unfeasible or unsuccessful.

Tumor induced osteomalacia in head and neck region: single center experience and systematic review

Tumor-induced osteomalacia in the head and neck region remains a challenging diagnosis to manage. Literature pertaining to management and outcome details remains sparse. We describe two cohorts: cohort 1 included seven patients from a single center in Western India with tumors located in paranasal sinuses (n = 3), intracranial (n = 2) and maxilla (n = 2). The unique features from our series is the management of persistent disease with radiation therapy (n = 2) and peptide receptor radionuclide therapy (PRRT) (n = 1). Cohort two has 163 patients identified from 109 publications for systematic review. Paranasal sinuses, mandible, intracranial disease, maxilla and oral cavity, in descending order, are reportedly common tumor sites. Within this cohort, mean age was 46 ± 14 years at presentation with 44.1% having local symptoms. Duration of symptoms varied from 1 to 240 months. Pre-surgery mean serum phosphorus was 1.4 ± 0.4 mg/dL and median FGF-23 levels were 3.6 (IQR:1.8-6.8) times of normal upper limit of normal. Majority (97.5%) were managed primarily with surgical excision; however, primary radiotherapy (n = 2) and surgery combined with radiotherapy (n = 2) were also reported. Twenty patients had persistent disease while nine patients had recurrence, more commonly noted with intracranial and oral cavity tumors. Surgery was the most common second mode of treatment employed succeeded by radiotherapy. Four patients had metastatic disease. The most common histopathological diagnosis reported is PMT mixed connective tissue, while the newer terminology 'PMT mixed epithelial and connective tissue type' has been described in 15 patients.

Varied presentation of sinonasal phosphaturic mesenchymal tumour: report of a case series with follow-up

PURPOSE

Phosphaturic mesenchymal tumour (PMT) of the paranasal sinuses is a rare tumour that is associated with oncogenous osteomalacia causing predominant musculoskeletal symptoms. We present a series of eight patients diagnosed to have PMT of the paranasal sinuses with varied presentation and highlight the appropriate evaluation required to arrive at the diagnosis.

METHODS

Retrospective review of eight patients diagnosed to have PMT-causing tumour-induced osteomalacia with follow-up data.

RESULTS

Eight patients, 4 males and 4 females, aged 36-67 years (mean = 44 years) presented with vague musculoskeletal symptoms (6 patients) or epistaxis (3 patients). Six patients were found to have hypophosphatemia, phosphaturia and raised FGF-23 levels preoperatively. All eight patients were found to have a tumour in the nose and/ paranasal sinuses with one patient having intracranial extension. All patients were treated with endoscopic excision of these tumours which resulted in resolution of symptoms and normalisation of biochemical abnormalities. In addition, one patient required a craniofacial resection. Histopathological features were consistent with PMT mixed connective tissue variant. Two atypical patients were seen. The longest follow-up was for 5 years and there was no evidence of recurrence during the follow-up period in any patient.

CONCLUSION

Diagnosis of PMT of the paranasal sinuses causing oncogenous osteomalacia requires a high index of suspicion when there are no ENT symptoms. Appropriate biochemical tests and histopathology lead to the correct diagnosis. Total endoscopic surgical excision leads to a good outcome.

Phosphaturic mesenchymal tumor with an admixture of epithelial and mesenchymal elements in the jaws: clinicopathological and immunohistochemical analysis of 22 cases with literature review

Information on the heterogeneity of phosphaturic mesenchymal tumor, a rare entity associated with tumor-induced osteomalacia, is limited. In this retrospective analysis of 222 phosphaturic mesenchymal tumors, 22 cases exhibited mixed mesenchymal and epithelial elements, which we propose to term "phosphaturic mesenchymal tumor, mixed epithelial, and connective tissue type." Phosphaturic mesenchymal tumor of the mixed epithelial and connective tissue type showed a distinctive and significant male predominance (male:female = 2.67:1), with most patients diagnosed at <40 years old. Moreover, all tumors were mainly located in the alveolar bone with focal invasion into surrounding soft tissue and oral mucosa, which could be detected preoperatively by oral examination. The mesenchymal component, composed of spindled cells resembling fibroblasts or myofibroblasts arranged in a storiform or fascicular pattern, exhibited a less prominent vasculature and lower cellularity than the typical phosphaturic mesenchymal tumor (mixed connective tissue type). The epithelial component was typically haphazardly and diffusely distributed throughout the tumor, forming small, irregular nests resembling odontogenic epithelial nests. All cases were immunoreactive for fibroblast growth factor-23, somatostatin receptor 2A, and NSE in both components. Mostly also demonstrated positive staining for CD99 (21/22, 96%), CD56 (16/22, 73%), Bcl-2 (21/22, 96%), and D2-40 (19/22, 86%) in one or both components. S100 was positive in both components in one of seven cases. Interestingly, immunoreactivity was typically stronger and more diffuse in the epithelial than in the paired mesenchymal components. The mesenchymal component was also diffusely positive for CD68 (17/17, 100%) and showed variable focal staining for SMA (15/22, 68%) and CD34 (9/19, 47 %). These results indicate that phosphaturic mesenchymal tumor of the mixed epithelial and connective tissue type has distinctive clinicopathological characteristics and a polyimmunophenotypic profile.

Ethmoid tumor and oncogenic osteomalacia: Case report and review of the literature

INTRODUCTION

Oncogenic osteomalacia is a very rare disease usually caused by a phosphaturic mesenchymal tumor, particularly the "mixed connective tissue type", secreting FGF-23 hormone.

OBJECTIVE

The authors report a case of ethmoid tumor associated with oncogenic osteomalacia and discuss management based on a review of the literature.

CASE SUMMARY

A 41-year-old woman with multiple fractures causing major disability was diagnosed with early-onset osteoporosis. CT scan followed by MRI, performed due to the concomitant presence of nasal obstruction, showed a right ethmoid tumor in contact with the dura mater and periorbital tissues, but with no signs of invasion. Endoscopic resection was performed with reconstruction of the defect of the cribriform plate by a nasoseptal flap. Nasal and bone symptoms subsequently resolved. Histological examination revealed a phosphaturic mesenchymal tumor.

DISCUSSION

Twelve cases of mesenchymal tumor of the ethmoid sinus associated with oncogenic osteomalacia have been reported to date. FGF-23 assay and whole-body MRI with STIR sequence are useful for the diagnosis. A very favorable outcome is observed after surgical treatment in the majority of cases.

Phosphaturic Mesenchymal Tumor: 2 New Oral Cases and Review of 53 Cases in the Head and Neck

Phosphaturic mesenchymal tumor (PMT) is a rare neoplasm that secretes fibroblast growth factor-23 (FGF-23) and causes oncogenic osteomalacia. It occurs in adults with equal gender distribution and the most common location is the lower extremities, followed by the head and neck. Besides osteomalacia, the clinical presentation includes bone pain and multiple bone fractures. Microscopic features consist of spindle cells, multinucleated giant cells, and calcifications embedded in a chondromyxoid matrix. Laboratory findings indicate normal calcium and parathyroid levels, hypophosphatemia, and increased levels of FGF-23 that usually revert to normal after surgical removal. Due to its rarity, the purpose of the study was to report 2 new oral cases of PMT and to review the literature in the head and neck. The first case occurred in the gingiva and had been present for 6 years. The second case was a recurrence of a previously diagnosed PMT in the right mandible that metastasized to the lung and soft tissue. The literature review included 53 cases in the head and neck. There was a predilection for extra-oral sites (76%) compared to intra-oral sites (24%) with paranasal sinuses considered the most common location (38%) followed by the mandible (15%). There were 9 recurrences that included 3 malignant cases indicating a potentially aggressive tumor. Due to the indeterminate biological behavior of PMT and its rarity, a comprehensive evaluation of medical, laboratory, radiographic, and histological findings are crucial for a definitive diagnosis and treatment.

Phosphaturic mesenchymal tumor of the brain without tumor-induced osteomalacia in an 8-year-old girl: case report

Phosphaturic mesenchymal tumor (mixed connective tissue variant) (PMT-MCT) are tumors that may cause tumor-induced osteomalacia and rarely appear intracranially. The authors describe the case of an 8-year-old girl who was found to have PMT-MCT with involvement of the cerebellar hemisphere and a small tumor pedicle breaching the dura mater and involving the skull. This was removed surgically in gross-total fashion without further complication. Histologically the tumor was confirmed to be a PMT-MCT. There was no evidence of tumor-induced osteomalacia. At the 42-month follow-up, the patient is doing well, has no abnormalities, and is free of recurrence. PMT-MCTs are rare tumors that may involve the brain parenchyma. A gross-total resection may be effective to cure these lesions.

Intracranial phosphaturic mesenchymal tumors

Hypophosphatemia with osteomalacia may be due to a neoplasm that produces fibroblast growth factor 23 (FGF-23), which inhibits phosphate reabsorption in the kidneys. Most of these tumors occur in bone or soft tissue and occasionally in the head, although intracranial occurrence is very rare. This report describes a tumor that caused hypophosphatemia and osteomalacia and was located entirely in the right anterior cranial fossa. Radiologically, the tumor resembled a meningioma; histologically, it was a low-grade phosphaturic mesenchymal tumor, mixed connective tissue variant (PMTMCT). After gross-total resection, the patient's symptoms abated and laboratory values normalized. The authors also studied another PMTMCT initially diagnosed as a hemangiopericytoma that involved the left anterior cranial fossa and ethmoid sinus, and reviewed reports of 6 other intracranial tumors that induced osteomalacia, 3 entirely in the anterior cranial fossa, 2 involving the anterior cranial fossa and ethmoid sinus, and 1 in the cavernous sinus. In older children or adults who have hypophosphatemia with osteomalacia and no personal or family history of metabolic, renal, or malabsorptive disease, a neoplasm should be suspected and an imaging workup that includes the brain is warranted, with particular attention to the anterior cranial fossa. Additionally, because there are some overlapping histological features between PMTMCTs and hemangiopericytomas, it may be helpful to assess tumoral FGF-23 expression by reverse transcriptase polymerase chain reaction or immunohistochemical analysis in patients with oncogenic osteomalacia from an intracranial tumor diagnosed as, or resembling, hemangiopericytoma.

Management of sinonasal hemangiopericytomas: a systematic review

BACKGROUND

Hemangiopericytomas are typically found in soft-tissue, but only rarely found in the sinonasal tract. Sinonasal hemangiopericytomas have been reported mostly through case studies, and optimal treatment is considered surgical excision. Classically, open surgical methods of tumor extirpation have been considered standard of care. With the wider use of endoscopic methods, an updated systematic review in terms of treatment is warranted.

METHODS

Cases were identified using a MEDLINE and PubMed search. Relevant studies were identified, and data was extracted regarding patient demographics, presenting symptoms, tumor characteristics, treatment, and outcomes.

RESULTS

A total of 128 cases were collected from 56 articles, consisting of case reports and series. The most common presenting symptoms were epistaxis, nasal obstruction, and facial pain/swelling/pressure. Computed tomography (CT) and X-ray were the most common modes of imaging during diagnosis and operative planning. The tumor often occupied multiple locations in the sinonasal tract at initial presentation. Surgical resection was the mainstay of treatment in 126 of the 128 cases (98.4%), either through open resection or endoscopic techniques. Surgical removal resulted in no recurrence in 79.7% of the cases. The use of endoscopic techniques increased significantly in the past decade. This review found no significant difference in terms of recurrence between endoscopic and open treatment groups, age, gender, and unilocality vs multilocality of tumor.

CONCLUSION

Surgical management remains the mainstay of treatment for hemangiopericytomas. Endoscopic resection of these lesions has increased over the last few decades and has become a safe, viable, and reasonable alternative to open resection.

Bilateral subtrochanteric fractures in tumour-induced osteomalacia caused by a nasal haemangiopericytoma

Bilateral insufficiency fractures of the proximal femur often have a pathological basis. Diagnosis of rare causes of insufficiency fractures can be challenging. Tumour-induced osteomalacia (TIO) is a rare paraneoplastic syndrome of mesenchymal tumours which leads to hypophosphataemia and osteomalacia. Suspected pathological fractures should be investigated thoroughly including a fasting serum phosphate level. Further investigations should include serum levels of fibroblast growth factor 23 (FGF23) which is a peptide hormone secreted by mesenchymal tumours. Available imaging modalities include Octreotide scanning which detects somatostatin receptors commonly expressed on mesenchymal tumours. After localisation and resection of the tumour, a full recovery from TIO is achievable.

Systematic review of treatment and prognosis of sinonasal hemangiopericytoma

BACKGROUND

This study was undertaken to determine the recurrence rate for open and endoscopic surgery and the clinical prognosis of this sinonasal tumor.

METHODS

A systematic review of individual cases of sinonasal hemangiopericytoma was performed. A total of 97 articles were included in the study and reviewed to extract the relevant information about each case.

RESULTS

In all, 194 cases of sinonasal hemangiopericytoma were identified. There were 53 recurrences (27.3%), 6 tumor-related deaths (3.1%), and 4 cases of metastases (2.1%). There was no significant difference between rate of recurrence for endoscopic or open resection (p = .06). Incomplete excision was the most important predictor of recurrence (odds ratio = 11.50, 95% confidence interval 3.76-36.82, p < .001). Radiotherapy may be advantageous in cases of incomplete surgical resection (p = .03).

CONCLUSIONS

Complete excision is essential to minimize tumor recurrence and radiotherapy may decrease the rate of recurrence in the case of incomplete resection. Current evidence does not suggest that open resection is superior to endoscopic resection.

Striking pathology gold: a singular experience with daily reverberations: sinonasal hemangiopericytoma (glomangiopericytoma) and oncogenic osteomalacia

Sinonasal hemangiopericytoma-like tumors(SNHPC)(glomangiopericytomas)were originally conceived as histologically similar to, but biologically distinct from, their soft tissue counterparts. Re-evaluation of "hemangiopericytiomas" has determined that SNHPC (glomangiopericytomas) represent bona-fide pericyte-derived tumors, whereas most soft tissue neoplasms previously designated as hemangiopericytomas represent cellular variants of solitary fibrous tumors or other lesions with a hemangiopericytomalike growth pattern. We present an interesting case of a woman with SNHPC (glomangiopericytomas) causing oncogenic osteomalacia, and discuss the recent advances in our understanding of phosphaturic mesenchymal tumors. This particular case is an example of "Striking Pathology Gold"-a situation where the pathologist actively guides the diagnostic process, and witnesses its repercussions. "Striking Pathology Gold" may be a rare event in one's career. However it serves to remind us of our place in the world as physicians. Working behind the scenes, we quietly change the course of countless individual destinies for the better.

Using (18)F-FDG PET/CT to Detect an Occult Mesenchymal Tumor Causing Oncogenic Osteomalacia

Oncogenic osteomalacia is a rare paraneoplastic syndrome characterized by renal phosphate excretion, hypophosphatemia, and osteomalacia. This syndrome is often caused by tumors of mesenchymal origin. Patients with oncogenic osteomalacia have abnormal bone mineralization, resulting in a high frequency of fractures. Tumor resection is the treatment of choice, as it will often correct the metabolic imbalance. Although oncogenic osteomalacia is a potentially curable disease, diagnosis is difficult and often delayed because of the small size and sporadic location of the tumor. Bone scintigraphy and radiography best characterize osteomalacia; magnetic resonance imaging findings are nonspecific. Here, we report a case of oncogenic osteomalacia secondary to a phosphaturic mesenchymal tumor that was successfully detected by (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT). This case illustrates the advantages of (18)F-FDG PET/CT in detecting the occult mesenchymal tumor that causes oncogenic osteomalacia.

Mesenchymal phosphaturic neoplasm in the maxillary sinus: a case report

The authors describe a case of oncogenic osteomalacia due to a mesenchymal phosphaturic tumour in the maxillary sinus. This is a paraneoplastic syndrome in which a tumour produces a peptide hormone-like substance (phosphatonin) that causes a urinary loss of phosphates resulting in a debilitating systemic condition. In this case, the patient experienced muscle stiffness, reduction of muscle tone, loss of weight and pathological fractures. Clinical and radiological examination revealed a tumour in the right maxillary sinus; all other results were negative. The diagnosis following pathology examination was mesenchymal phosphaturic tumour with a haemangiopericytoma-like vascular pattern. Different histological types of mesenchymal tumours can be associated with paraneoplastic syndrome, but their localization in the paranasal sinuses is rare. The correct diagnosis allows the appropriate therapeutic approach, which can lead to an almost immediate resolution of the clinical situation after surgical removal of the neoplasm as in the present case. Oncogenic osteomalacia is rare, particularly in the maxillofacial region, and only a few cases have been reported.

Oncogenic osteomalacia in a patient with an ethmoid sinus tumour

OBJECTIVE

To highlight the clinical presentation and management of a rare case of oncogenic osteomalacia due to an ethmoid sinus tumour.

MATERIALS AND METHODS

We examined the case records of a 55-year-old man who presented with progressive fatigue, weakness and bone pain, and noted the clinical presentation, laboratory investigations, computed tomography findings, operative notes and follow-up details.

CONCLUSION

Oncogenic osteomalacia secondary to a paranasal sinus neoplasm is a rare entity. The causative tumour is often occult and may be missed by routine clinical examination. This case report illustrates the appropriate pattern of evaluation and management to ensure a successful outcome.

Oncogenic osteomalacia from pterygopalatine fossa mass

INTRODUCTION

Oncogenic osteomalacia, or tumour-induced osteomalacia, is an uncommon cause of osteomalacia. It has been reported to occur in patients with hypophosphataemia due to excess renal phosphate excretion secondary to mesenchymal tumours. Occurrence of this pathological process in the head and neck is extremely rare.

METHODS

Case report and literature review.

RESULTS

We present a case of a 73-year-old woman with tumour-induced osteomalacia. She was initially followed by the endocrinologists for osteomalacia and pathological fractures. An indium-111 pentetreotide scan showed activity in the left pterygopalatine fossa. A mass was endoscopically resected, and the histopathological appearance was consistent with a haemangiopericytoma. Following surgery, the patient's hypophosphataemia and vitamin D deficiency corrected and her symptoms resolved.

CONCLUSIONS

Oncogenic osteomalacia, or tumour-induced osteomalacia, is a rare entity in the head and neck. Current research is elucidating the mechanism by which phosphaturic wasting occurs. In most patients, symptoms resolve once the offending tumour is removed.

Case report: Solitary plasmacytoma of bone with oncogenic osteomalacia: recurrence of tumour confirmed by PET/CT. A case report with a review of the radiological literature

We describe a case of oncogenic osteomalacia secondary to solitary plasmacytoma of the vertebral body of T3. The patient presented with symptoms of hypophosphataemia. Following the initial diagnosis, the lesion was surgically resected with good results, although several follow-up procedures, including bone grafting, were necessary to stabilize the thoracic spine. The lesion recurred almost 15 years after its initial resection, again presenting with hypophosphataemia and neurological symptoms suggestive of local tumour recurrence. A variety of radiological examinations were performed in an attempt to confirm and localize recurrent tumour, including bone scintigraphy, (111)indium octreotide scintigraphy, high-resolution CT and MRI of the thoracic spine, but these yielded only negative or equivocal results owing, in part, to the presence of extensive post-operative changes, and also to a difference in the MR signals of the recurrent and original tumours. Positron emission tomography (PET/CT) demonstrated a solitary focus of intense fluorodeoxyglucose uptake in the T3 vertebral body, enabling a definitive diagnosis of recurrent plasmacytoma. This case illustrates the diagnostic value of PET/CT in the setting of challenging post-operative changes in the surrounding tissue and in the appearance of the tumour itself. Relevant related imaging literature is also reviewed.

A haemangiopericytoma of the ethmoid sinus causing oncogenic osteomalacia: a case report and review of the literature

Oncogenic osteomalacia is a rare cause of osteomalacia. It is caused by a tumour which is generally benign. These tumours, when identified, are often found in the head and neck region. The case is reported here of a haemangiopericytoma isolated in the ethmoid sinus, and the literature regarding tumours at this site is reviewed. Including the present case there are five reported in the world literature of an ethmoid sinus tumour causing oncogenic osteomalacia. The treatment for this disease is excision of the mass, which is where the head and neck specialist's expertise is required.

Oncogenic osteomalacia: exact tumor localization by co-registration of positron emission and computed tomography

In oncogenic osteomalacia, the causative tumor is almost always difficult to find. A novel diagnostic approach is presented that facilitates a precise and rapid localization of the associated lesion by PET-CT co-registration using the radiotracer (68)Ga-DOTANOC.

INTRODUCTION

Oncogenic osteomalacia (OOM) is an uncommon disorder characterized by hyperphosphaturia, hypophosphatemia, decreased vitamin D(3) serum levels, and osteomalacia. The paraneoplastic syndrome is exclusively driven by a small somatostatin receptor (sst)-positive tumor that produces phosphatonins, proteins that cause renal phosphate loss. OOM can be cured completely on tumor removal. However, the exact tumor localization is the most challenging step, because the lesion is notoriously difficult to detect by common imaging techniques.

MATERIALS AND METHODS

A 60-year-old woman complained of severe pain in her back and chest wall, muscle weakness, and reduced physical activity for >1 year. She suffered a metatarsal fracture and presented with hyperphosphaturia and hypophosphatemia. OOM was suspected, and a meticulous search for the tumor was initiated by conventional imaging techniques, sst-mediated imaging using (111)In-octreotide scintigraphy, and (68)Ga-DOTANOC-based positron emission tomography (PET)-CT co-registration. (68)Ga-DOTANOC is a novel radiopharmaceutical compound in which the somatostatin analog octreotide is modified at position 3, chelated with DOTA, and complexed with (68)Gallium. (68)Ga-DOTANOC has an improved affinity to sst2 and sst5 relative to other radiopeptides.

RESULTS

Whereas common imaging techniques such as CT failed to localize the tumor, (111)In-octreotide scintigraphy was able to detect the lesion, but only PET-CT using (68)Ga-DOTANOC revealed the exact tumor localization in the right femoral head. On tumor resection, the well being of the patient improved significantly, and biochemical parameters returned to normal.

CONCLUSIONS

(68)Ga-DOTANOC-based PET-CT is a novel and powerful approach to detect sst-positive tumors in a timely manner and to provide highly resolved images facilitating the development of a therapeutic strategy.

Usefulness of 201Tl and 99mTc MIBI scintigraphy in a case of oncogenic osteomalacia

A 45-year-old male was admitted with difficulty in walking due to leg pain. At the time of the first visit, a reduced serum phosphorus concentration and an increased serum alkaline phosphatase concentration of unknown etiology were observed. Either a whole body bone scintigraphy or CT of the neck, chest and abdominal region did not reveal any underlying disease. However both the whole body 201Tl scintigraphy and 99mTc MIBI SPECT showed accumulation in the right knee region, and a small tumor was detected by MRI examination. After a diagnosis of oncogenic osteomalacia due to this tumor was determined the tumor was surgically removed, and turned out to be a hemangiopericytoma. By removal of the tumor, either the symptoms or the laboratory data were improved significantly. In this case, both 201Tl scintigraphy and 99mTc scintigraphy MIBI were useful in identifying the location of the tumor which caused oncogenic osteomalacia.

Most osteomalacia-associated mesenchymal tumors are a single histopathologic entity: an analysis of 32 cases and a comprehensive review of the literature

Oncogenic osteomalacia (OO) is a rare paraneoplastic syndrome of osteomalacia due to phosphate wasting. The phosphaturic mesenchymal tumor (mixed connective tissue variant) (PMTMCT) is an extremely rare, distinctive tumor that is frequently associated with OO. Despite its association with OO, many PMTMCTs go unrecognized because they are erroneously diagnosed as other mesenchymal tumors. Expression of fibroblast growth factor-23 (FGF-23), a recently described protein putatively implicated in renal tubular phosphate loss, has been shown in a small number of mesenchymal tumors with known OO. The clinicopathological features of 32 mesenchymal tumors either with known OO (29) or with features suggestive of PMTMCT (3) were studied. Immunohistochemistry for cytokeratin, S-100, actin, desmin, CD34, and FGF-23 was performed. The patients (13 male, 19 female) ranged from 9 to 80 years in age (median 53 years). A long history of OO was common. The cases had been originally diagnosed as PMTMCT (15), hemangiopericytoma (HPC) (3), osteosarcoma (3), giant cell tumor (2), and other (9). The tumors occurred in a variety of soft tissue (21) and bone sites (11) and ranged from 1.7 to 14 cm. Twenty-four cases were classic PMTMCT with low cellularity, myxoid change, bland spindled cells, distinctive "grungy" calcified matrix, fat, HPC-like vessels, microcysts, hemorrhage, osteoclasts, and an incomplete rim of membranous ossification. Four of these benign-appearing PMTMCTs contained osteoid-like matrix. Three other PMTMCTs were hypercellular and cytologically atypical and were considered malignant. The 3 cases without known OO were histologically identical to the typical PMTMCT. Four cases did not resemble PMTMCT: 2 sinonasal HPC, 1 conventional HPC, and 1 sclerosing osteosarcoma. Three cases expressed actin; all other markers were negative. Expression of FGF-23 was seen in 17 of 21 cases by immunohistochemistry and in 2 of 2 cases by RT-PCR. Follow-up (25 cases, 6-348 months) indicated the following: 21 alive with no evidence of disease and with normal serum chemistry, 4 alive with disease (1 malignant PMTMCT with lung metastases). We conclude that most cases of mesenchymal tumor-associated OO, both in the present series and in the reported literature, are due to PMTMCT. Improved recognition of their histologic spectrum, including the presence of bone or osteoid-like matrix in otherwise typical cases and the existence of malignant forms, should allow distinction from other mesenchymal tumors. Recognition of PMTMCT is critical, as complete resection cures intractable OO. Immunohistochemistry and RT-PCR for FGF-23 confirm the role of this protein in PMTMCT-associated OO.

Congenital sucrase-isomaltase deficiency presenting with failure to thrive, hypercalcemia, and nephrocalcinosis

BACKGROUND

Disaccharide Intolerance Type I (Mendelian Interance in Man database: *222900) is a rare inborn error of metabolism resulting from mutation in sucrase-isomaltase (Enzyme Catalyzed 3.2.1.48). Usually, infants with SI deficiency come to attention because of chronic diarrhea and nutritional evidence of malabsorption.

CASE PRESENTATION

We describe an atypical presentation of this disorder in a 10-month-old infant. In addition to chronic diarrhea, the child displayed severe and chronic hypercalcemia, the evaluation of which was negative. An apparently coincidental right orbital hemangioma was detected. Following identification of the SI deficiency, an appropriately sucrose-restricted, but normal calcium diet regimen was instituted which led to cessation of diarrhea, substantial weight gain, and resolution of hypercalcemia.

CONCLUSIONS

This case illustrates that, similar to congenital lactase deficiency (Mendelian Interance in Man database: *223000, Alactasia, Hereditary Disaccharide Intolerance Type II), hypercalcemia may complicate neonatal Sucrase-Isomaltase deficiency. Hypercalcemia in the presence of chronic diarrhea should suggest disaccharide intolerance in young infants.