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AIntroduction: Doege-Potter's syndrome is a rare paraneoplastic syndrome, consisting in hypoglycemia and solitary fibrous tumor of the pleura. These tumors represent < 5% of all pleural tumours and can only be cured by surgery. In this article, we report a case of a patient presenting with severe hypoglycemia, as the only symptom, and a mass occupying the entire left hemithorax. Case presentation: A54 year old female with severe hypoglycemia, a chest radiography with almost total opacification of the left hemithorax and a computed tomography scan with a mass in the left hemithorax. Surgery was performed and a mass with 30cm × 18cm × 11cm weighing 3195g was resected. The postoperative course was uneventful with immediate resolution of the hypoglycemia. The immunohistochemistry diagnosis was solitary fibrous tumor of the pleura. Conclusions: Solitary fibrous tumor of the pleura are very rare. Less than 5% are associated with hypoglycemia, taking the form of Doege-Potter Syndrome. Radiation therapy and chemotherapy have shown low response rate and complete surgical resection is the only procedure that offers cure. This case reports describes a rare giant solitary fibrous tumor of the pleura with severe hypoglycemia, successfully treated by surgery. Long-term follow-up of the patient after the surgery is necessary for detection of any possible recurrence.

Doege-Potter syndrome is a paraneoplastic syndrome characterized by non-islet cell tumor hypoglycemia secondary to a solitary fibrous tumor. These tumors are rare and usually asymptomatic. The syndrome of hypoglycemia is seen in less than 5% of the cases, and the associated tumors are large with a high mitotic rate. The cause of hypoglycemia is related to insulin-like growth factors produced by these tumors called "big" IGF-2. Several biological tests can demonstrate the increase of "big" IGF-2 plasma levels confirming the diagnosis of non-islet cell tumor induced hypoglycemia. The diagnosis is suggested by imaging but diagnostic confirmation is provided by the surgery, which remains the treatment of choice. Resection in many cases is the cure leading to hypoglycemia resolution. Recurrences and malignant transformations are possible which imposes a long-term monitoring. We report a case with relapsed malignant pleural fibrous tumor for which the pathophysiological mechanism of hypoglycemia could be documented as a paraneoplastic syndrome., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Localized fibrous tumors of the pleura are rare. If there are symptomatic, the symptoms are based on hormone production or size. Complete resection offers the best results. However, recurrence is reported in a significant number of patients. Usually no oncologic treatment is necessary.

Falls due to hypoglycaemia in the elderly is usually a complication of diabetic treatment. In the absence of diabetes, hypoglycaemia may be due to insulin or insulin-like producing tumours. The Doege-Potter syndrome is a rare paraneoplastic syndrome, characterised by non-islet cell tumour hypoglycaemia (NICTH) secondary to a solitary fibrous tumour that secretes insulin-like growth factor (IGF) 2. Definitive treatment of hypoglycaemia due to NICTH is by tumour resection. Our patient was a 78-year-old woman admitted after a fall with a facial injury and a history of significant weight loss. Her blood sugar was persistently low despite intravenous dextrose infusion. CT of the thorax revealed a large heterogeneous mass measuring 11.6×16.3×15.6 cm in the right hemithorax. A biopsy of the mass was reported as a solitary fibrous tumour. Biochemical investigations revealed low insulin, C-peptide, IGF-1 and a high IGF-2:IGF-1 ratio, consistent with NICTH. The patient underwent tumour resection and the hypoglycaemia normalised completely immediately after surgery., (2015 BMJ Publishing Group Ltd.)

Syndrome Doege-Potter is a paraneoplastic syndrome in which hypoglycemia is the result of tumors producing insulin growth factor-like (IGF-II) it is most often solitary fibrous tumor of the pleura (TFSP). These are rare and may be discovered incidentally, during non-specific respiratory symptoms or during hypoglycemia. Hypoglycemia occurs in tumors of large volume and it disappears after surgery, which is the treatment of choice for a permanent cure in most cases. We present a case of Doege-Potter syndrome whose interest is to consider the TFSP as a cause of hypoglycemia in patients with pleural tumors., (Copyright © 2011. Published by Elsevier Masson SAS.)

We report a case of a 61 year-old man who presented with refractory non-insulin mediated hypoglycaemia. A chest radiograph showed a right lung opacity, which was confirmed as a large intra-thoracic mass by computed tomography (CT) of the thorax. CT-guided biopsy with histological examination revealed features of a solitary fibrous tumour of low malignant potential. We discuss the association of solitary fibrous tumour of the pleura (SFTP) with hypoglycaemia, and the management of such rare tumours.

Solitary fibrous tumor of the pleura (SFTP) is rare. A 73-year-old man, without past history of diabetes mellitus, was admitted to hospital with profound hypoglycemia, loss of consciousness and respiratory failure. CT indicated a huge heterogenous mass lesion (12 x 12 x 17 cm) at the right thoracic cavity with total atelectasis of the right lower lung. He underwent a standard thoracotomy with complete excision of the tumor. Pathology indicated malignant SFTP with insulin-like growth factor-binding protein-2 production. There were no further incidences of hypoglycemia or respiratory failure after excision of the tumor. Hypoglycemia resulting from a solitary fibrous tumor is uncommon. Standard thoracotomy and complete resection of this giant tumor provided a good result for the present patient.

Introduction: Solitary fibrous tumours of the pleura are uncommon and discovered fortuitously or in patients with non-specific respiratory symptoms. When associated with hypoglycaemia, they are commonly referred to as Doege-Potter syndrome., Case Outline: A 68-year old woman presented with a large pleural mass. She had a long history of headache and decreased consciousness with one-year worsening dyspnoea and right-sided chest pain. The chest X-ray revealed an enormous opacity occupying almost the entire right hemithorax. Endocrine tests showed an extremely reduced glucose level and blood concentration of insulin, C-peptide, glucagon, growth hormone and catecholamines within normal range. After fine-needle aspiration, by histological and immunohistochemical analysis, a benign solitary fibrous pleural tumour was diagnosed. Although surgical resection of such a huge tumour with hypoglycaemia is usually curative, our patient declined surgery and opted for conservative treatment with intravenous glucose., Conclusion: Clinicians should be aware of this rare, but important cause of hypoglycaemia and exclude a fibrous pleural tumour in the assessment of their patients.

Pleural fibroma or solitary fibrous tumor of the pleura (SFTP) is a rare tumor generally discovered fortuitously or in patients with non-specific respiratory symptoms, more rarely with hypoglycemia. We report the case of a 51-year-old man with a history of smoking (30 pack-years) and no other disease history whose chest x-ray revealed an enormous opacity occupying the lower two-thirds of the left hemithorax. This radiological anomaly had led to episodes of lipothymia three months earlier together with mental confusion in the morning as well as an episode of hypoglycemia (0.48 g/l) which rapidly resolved after administration of hypertonic dextrose. Ultrasonography and chest scan were performed later and confirmed the tissular nature of the opacity which was well limited with a left base. Minimally abundant homolateral pleural effusion was also noted. The diagnosis of SFTP revealed by hypoglycyemia was the most probably diagnosis. Emergency thoracotomy enabled removal of a hard tumor weighing 2115 g. Histology confirmed the diagnosis of benign SFTP. Hypoglycemia in the context of SFTP would be related to tumor secretion of insulin-like proteins. Complete emergency resection is required to avoid the risk of life-threatening hypoglycemia.

Many neoplastic tumors exhibit paraneoplastic syndromes manifested by endocrinopathy. This is particularly true of intrathoracic tumors such as lung cancers, thymomas, carcinoid tumors and mediastinal germ cell neoplasm. Fibrous tumors of the pleura are rare intrathoracic tumors, which are usually benign and often grow to huge size. A subset of these neoplasms present with the syndrome of hypoglycemia. Although first reported more than 70 years ago, the diagnosis is rarely considered when a patient presents with syncope and hypoglycemia. This article reports a patient who presented with a large pleural mass and a hypoglycemic syndrome. (The disease was surgically cured.) The probable mechanism of hypoglycemia is discussed.

Objective: To describe the adverse effects of continuous intravenous infusion of glucagon as therapy for tumor-induced hypoglycemia and to correlate these treatment-related effects with symptoms of endogenous hyper-glucagonemia., Methods: We reviewed three cases in which patients received continuous glucagon therapy for tumor-induced hypoglycemia and experienced adverse side effects to the treatment. We noted that these adverse events were consistent with changes that are described in the literature as symptoms of the glucagonoma syndrome., Results: Continuous intravenous glucagon infusion has evolved as a reliable and efficacious modality for the treatment of tumor-induced hypoglycemia. We report the adverse events of venous thromboembolism, necrolytic migratory erythema, and angular cheilitis in conjunction with continuous intravenous glucagon treatment. These complications resemble symptoms that characterize the human model of hyperglucagonemia--the glucagonoma syndrome--which is associated with hyperglucagonemia and alpha-islet cell neoplasms of the pancreas., Conclusion: Symptoms that characterize the islet cell neoplasm-related glucagonoma syndrome may develop in patients receiving an infusion of exogenous glucagon. This observation lends support to the suggestion that glucagon may have a direct, causative role.

Solitary fibrous tumors (SFT) of the pleura are a rare neoplasm, with benign biological behaviour. Recurrences are rare, and no distant metastases are described in the literature. SFT can secrete hormone-like substances, responsible for paraneoplastic syndromes. The authors describe a case of severe hypoglycaemia due to insulin-like growth factor II (IGF-2)'s secretion by a giant SFT of the pleura. Hypoglycaemia was controlled by the resection of the tumor. Diagnosis and surgical management of these neoplasms are also discussed.

We present three cases of malignant solitary fibrous tumors of the pleura (SFTP) that produced recurrent hypoglycemia. Removal of the tumors produced normoglycemia. The tumors were well circumscribed and lobulated, and consisted of firm masses weighing 1,150 g to 1,450 g with the greatest diameter of 15 to 20 cm. The tumors were composed of spindle cells in fascicles or in a haphazard arrangement and were highly cellular and mitotically active (3-8 mitoses/10 high-power fields), showing histologically malignant features. Ultrastructurally, fibroblastic features of the tumor cells were present. Insulin-like growth factors (IGF) have been implicated in the presentation of hypoglycemia. The serum insulin and C-peptide levels were not elevated. Serum IGF-I levels were also low with values of 97.4, 157.1 and 51.9 ng/mL (ref. 125-317 ng/mL), respectively. However, tumor cells were strongly positive for IGF-I receptor on immunohistochemical analysis. It is tempting to speculate that IGF-I contributes to the hypoglycemia, even though the circulating levels were low.

We describe two cases of elderly women who presented hypoglycemic episodes with suppressed levels of insulin and insulin-like growth factor I. They were found to have huge malignant solitary fibrous tumor of the pleura. The tumors had rich vascularization on enhanced CT scans and showed characteristic low signal intensity on T2-weighted MR images. This paraneoplastic hypoglycemia is caused by an incompletely processed precursor of insulin-like growth factor II secreted from the tumor. Hypoglycemia and insulin suppression were resolved after removal of the tumors.

Objective: To describe the first patient with a neuroendocrine tumor secreting serotonin, insulin, and glucagon and having the corresponding clinical syndromes., Methods: We present a detailed case report, including serial laboratory and clinical findings, in a man with type 2 diabetes, symptomatic hypoglycemia, and the carcinoid syndrome and in whom a plurihormonal metastatic neuroendocrine neoplasm was ultimately diagnosed., Results: In a 58-year-old man with type 2 diabetes, which was treated effectively with a sulfonylurea for 7 years, episodes of hypoglycemia developed. After discontinuation of the orally administered agent, the hypoglycemic episodes initially resolved but then recurred and were associated with inappropriately increased plasma insulin concentrations. In addition, the patient had symptoms and biochemical evidence of the carcinoid syndrome. Computed tomography of the abdomen showed multiple hypodense lesions in the liver, and ultrasound-guided fine-needle aspiration of a liver mass was performed. Undifferentiated neuroendocrine tumor with hepatic metastatic involvement was diagnosed. After a hepatic artery embolization procedure, the hypoglycemia was alleviated, but hyperglycemia soon recurred, associated with inappropriately increased serum glucagon concentrations. The patient's course strongly suggested the presence of a plurihormonal tumor secreting serotonin, insulin, and glucagon., Conclusion: To our knowledge, this is the first reported case of a patient with a neuroendocrine neoplasm secreting serotonin, glucagon, and insulin, manifested by the carcinoid syndrome, hyperglycemia, and hypoglycemia.

Background and Objective: Non-islet-cell tumour hypoglycaemia (NICTH) is a rare disorder and has been explained by oversecretion of non mature IGF-II and dysregulation of the IGFs sytem. The mechanisms responsible for tumoural IGF-II overexpression in NICTH have been rarely studied. We report an extensive study of IGF-II and IGFBPs as well as chromosome 11p15 gene expression regulation in a case of a pleural fibrosarcoma in a 63-year-old patient presenting with NICTH., Methods and Results: Abnormal high molecular weight precusor forms of IGF-II were present in the patient's serum and were associated with dramatic alterations in the circulating levels of IGF-I, IGF-II and their binding proteins, as well as an inhibition of the somatotroph axis. These alterations returned to normal following complete surgical removal of the tumour. No structural change in chromosome 11p15 region was apparent in the tumour. However, dysregulation of this imprinted region was demonstrated, leading to the loss of imprinting of the IGF-II gene associated with high IGF-II expression, and by contrast decreased level of expression of H19 and p57KIP2 genes. Recurrence of the tumour four years latter was not associated with hypoglycaemia or changes in the levels of circulating IGFs or IGFBPs, despite IGF-II overexpression by the tumour. This suggests that a large tumour volume is required to reach high enough levels to cause changes in the levels of circulating IGFs and IGFBPs, and to cause hypoglycaemia., Conclusion: These results suggest that a dysregulation of gene expression and imprinting of chromosome 11p15 region is associated with tumour growth and IGF-II overexpression in non-islet-cell tumour hypoglycaemia.

Recurrent hypoglycemia occurred in a 58-year-old woman with a solitary fibrous tumor of the pleura and exhibiting CD34 immunopositivity. During episodes of hypoglycemia, serum high-molecular-weight insulin-like growth factor II (big IGF-II) was elevated. After removal of the tumor containing IGF-II, the hypoglycemia and serum big IGF-II disappeared. This was followed by an increase in normal IGF-II. We speculate that the primary cause of hypoglycemia in this patient was the presence of big IGF-II produced by the solitary fibrous tumor of the pleura. To our knowledge, the presence of this type of IGF-II in CD34+ solitary fibrous tumors of the pleura has not been described to date in the literature.

We report the interesting case of an elderly woman who presented with hypoglycaemic episodes and weight loss. She was found to have a solitary fibrous tumour weighing more than 1.7 kg arising from the diaphragmatic pleura, which had been producing insulin-like growth factor II. After surgical removal of this well-encapsulated, pedunculated tumour her hypoglycaemia resolved and she returned to normal both clinically and biochemically.

Extrapancreatic tumor hypoglycemia (EPTH) is associated with increased amounts of high-molecular-weight precursor forms of insulin-like growth factor (IGF)-II ('big-IGF-II') that have a primary role in the pathophysiology of hypoglycemia. In the present study, using Western ligand and immunoblotting methods, we investigated IGF-binding proteins (IGFBPs), IGFBP-3 proteolysis and big-IGF-II in pre- and postoperative serum from two patients with EPTH due to benign pleural fibroma. In the preoperative serum, IGFBP-3 was reduced and IGFBP-2 was increased compared with that from an age-matched healthy control. IGFBP-3 proteolysis was dramatically reduced in one patient, whereas no major alteration was observed in the other (9% and 120% of control serum, respectively). IGFBPs progressively returned to a subnormal pattern in postoperative serum, whereas IGFBP- 3 proteolysis remained greater than in preoperative serum in both patients at days 14 and 90 after surgery. High-molecular-weight forms of IGF-II predominate in EPTH serum (65% and 57% of total IGF-II immunoreactivity in patients 1 and 2, respectively, compared with 2 5% in control serum). Two forms, of molecular mass 10 and 12 kDa ('standard big-IGF-II') were present in both EPTH and control sera, whereas two additional forms, of molecular mass 15 and 18 kDa ('big big-IGF-II') were observed in EPTH sera only. Big big-IGF-II represented 72% and 55% of total high-molecular-weight forms of IGF-II in the two EPTH sera, respectively. All big forms of IGF-II disappeared from the serum as early as 6 h after surgery. This study shows that combination of simple Western blotting methods, available routinely in most laboratories, should prove useful in providing reliable physiopathological information in EPTH.

A case of malignant solitary fibrous tumor (SFT) is reported, occurring in a 61-year-old man with frequent hypoglycemia. Endocrinological analyses showed high serum levels of insulin-like growth factor II (IGF-II) and suppressed secretion of insulin. After the removal of a pleural tumor, which weighed 3150 g, serum IGF-II levels returned to normal and hypoglycemic attacks ceased. The tumor was composed of uniform spindle cells arranged in bundles, and fascicles with varying amounts of collagen and reticulin fibers. Mitotic figures at the rate of 6/10 high-power fields, and frequent foci of necrosis and hemorrhage were seen. Almost all of the tumor cells were immunohistochemically positive for vimentin and CD34. Electron microscopy revealed the immature mesenchymal or myofibroblastic nature of the tumor cells. These findings are consistent with malignant SFT of the pleura. Moreover, the tumor produced IGF-II mRNA as demonstrated by northern blot analysis. Thus, hypoglycemia of this patient was induced by SFT through the production and secretion of IGF-II.

A case with recurrent hypoglycemias following a thoracic tumor is presented. Neurologic symptoms due to hypoglycemia were dominant. Subcutaneous somatostatin was administrated preoperatively and hypoglycemia was controlled following tumor resection. Histology analysis shows a localized fibrous pleural tumor. Origin has been widely questioned but now it is accepted to be mesenchymal and not mesothelial. Lung disease owing to chronic compression of the tumor made necessary a lobectomy. Postoperative atelectasis required reoperation and a pneumonectomy was performed. To date insulin-like factors secreted by the tumor are supposed to be responsible for hypoglycemics discharges.

Hypoglycemia is known to be a rare consequence of non-islet cell tumors. A patient having severe, episodic hypoglycemia was found to have a large mass occupying the right hemithorax. The hypoglycemia resolved immediately after surgical removal of the tumor. Histologic examination of the tumor revealed localized fibrous mesothelioma.

Hypoglycemia in patients with nonislet cell tumors is often secondary to overexpression of tumor insulin-like growth factor (IGF) II. In these patients the formation of serum complexes between IGFs, IGF binding protein-3 (IGFBP-3), and the acid-labile subunit (ALS) is impaired. An 87-yr-old woman with nonislet cell tumor hypoglycemia resulting from a localized fibrous tumor of the pleura was treated for 97 days with graded doses of prednisolone (30, 10, and 5 mg/day) followed by GH (1, 4, 8, 4, and 2 U/day). Both prednisolone and GH alleviated the hypoglycemia, concomitantly with increases in IGF-I, IGFBP-3, and ALS levels. Pretreatment serum IGFBP-2 and IGFBP-6 levels were greatly elevated, but as glucose normalized with treatment, only IGFBP-2 decreased, showing an inverse correlation with glucose (r = 0.716). IGFBP-1 gave a variable pattern not clearly related to blood glucose. Both treatments caused a redistribution of serum IGFBP-3 from binary- to ternary-complexed forms. However, only prednisolone improved the ability of IGFBP-3 to bind ALS in vitro. Prednisolone also suppressed IGF-II, the effect being confined to pro-IGF-II forms. Compared with normal IGF-II, pro-IGF-II inhibited ALS binding to IGFBP-3 in vitro. Although prednisolone and GH reverse hypoglycemia by different mechanisms, with only prednisolone suppressing tumor IGF-II secretion, both increase the formation of ternary IGF-IGFBP-3 complexes. We conclude that the failure of serum IGFBP-3 and tumor IGF-II to complex with ALS is a primary cause of hypoglycemia in nonislet cell tumor hypoglycemia.

Background: In nondiabetic women, pregnancy alone rarely causes clinical hypoglycemia. Non-islet cell tumors have recently been shown to be associated with the production of insulin-like growth factor II (IGF-II) and a paraneoplastic syndrome resulting in hypoglycemia. A case report and review of pathophysiologic mechanisms involved is presented., Case: A 38-year-old multigravida presented suffering from clinical and biochemical hypoglycemia, which was found to be secondary to a mesothelioma of the pleura and ectopic IGF-II production. Tumor resection was performed during the 13th gestational week. The mother became euglycemic immediately after the surgery and remained asymptomatic. Clinical indicators of pregnancy and an ultrasound scan after the surgery were consistent with a normal viable fetus., Conclusion: Symptomatic hypoglycemia and other medical conditions occurring during pregnancy require immediate diagnosis and treatment. In addition to the more common causes, documented cases of medical conditions due to paraneoplastic syndromes of ectopic hormone production during pregnancy have been described. This case establishes the non-islet cell tumor with IGF-II-induced hypoglycemia as another such syndrome to be considered when evaluating hypoglycemia in pregnancy.

Some non-islet tumors can induce hypoglycemia. We report a case of an intrathoracic giant tumor accompanied by hypoglycemia. The patient was a 53-year-old woman who was found to have hypoglycemia. Chest X-ray film showed a giant tumor in the left hemithorax and rightward shift to the mediastinum. CT and MRI revealed that the tumor's border was clear. The tumor was removed by sternotomy with third and seventh inter-costal incisions. The tumor was lobulated but its border was clear. It seemed to have grown from the posterolateral thoracic wall. After the tumor was removed, re-expansion pulmonary edema occurred but was relieved by diuretics and respiratory management. Histologic findings indicated that it was probably a thymoma or a localised mesothelioma, but it could not be identified even with special stains. Solitary fibrous mesotheliomas are sometimes complicated by hypoglycemia, and some of them produce insulin-like growth factor (IGF). In this case, the pre-operative level of immuno-reactive insulin was low, so the tumor may have produced IGF.

Recurrent hypoglycemia occurred in a 48-year-old woman with a localized pleural mesothelioma. During hypoglycemia, serum high molecular weight insulin-like growth factor II (IGF-II) was elevated. The tumor also contained a high level of high molecular weight IGF-II. We propose that the primary cause of the hypoglycemia in this patient was the high molecular weight IGF-II produced by the tumor.

A 72-year-old woman was admitted to the hospital because of hypoglycemia. Her glucose level on admission was 40 mg/dl. A giant intrathoracic mass was demonstrated on X-ray, Computerized tomographic scan of the cerebrum showed no abnormalities. Serum insulin and C-peptide levels were within normal limits. The mass (weight 2.3 kg) and the right lower lobe were excised by thoracotomy and the hypoglycemia ceased. Pathological examination revealed the mass to be a localized fibrous tumor of the pleura.

The authors present a case of a 73 year old female patient. She had a left side pleural mesothelioma and had been operated thrice. At the third operation an abdominal propagation joined to the thoracic mesothelioma. Starting from this third surgery severe hypoglycemic episodes illustrated the clinical pictures. The electronmicroscopy of the resected tumor mass documented the presence of neurosecretory granules. This strongly suggests that tumor mass produced a substance which could have been responsible for the hypoglycemic episodes. Due to the fact the insulin levels measured during severe hypoglycemias were always on a low level, we suppose that an insulin like material (IGF--II) was responsible for the above mentioned symptoms. The authors briefly review the literature.

The authors report a case of pleural fibrosarcoma associated with severe hypoglycaemia. Chromatography of the patient's serum and tumour fragments revealed a substance with a high molecular weight and an insulin-like activity. Professor Poffengarger's laboratory identified this substance as Non Suppressible Insulin-Like Protein or NSILAp which induces insulin-like effects on various tissues. A review of the literature is presented in the light of this case.

We report the case of a patient suffering from a glandular pleural lesion. The evolution of the disease was punctuated by periods of hypoglycaemia, which caused a coma. There was no clinically evident explanation for these hypoglycaemic episodes. Investigations revealed adrenal failure, but this adrenal failure was unrelated to the neoplastic process in the patient. This case is a reminder that the cause of hypoglycaemia associated with tumours can really have a paraneoplastic origin and justifies an in depth study to achieve an aetiological diagnosis.

Spontaneous hypoglycaemia was the presenting feature of a man with a large subpleural fibroma. Preoperative and postoperative studies support the view that the tumour induced hypoglycaemia was due to the secretion of peptide hormones by the tumour.

A 64 year old woman with a long history of "drop attacks" and dizzy spells was found to have spontaneous hypoglycaemia. A slowly enlarging pleural mass had been present for at least five years. At thoracotomy the mass (weight 1.7 kg) was excised and the hypoglycaemia ceased. Histologically the tumour was a pleural fibroma, with no features of malignancy. Endocrine tests before surgery showed a subnormal growth hormone response to spontaneous hypoglycaemia, a reduced concentration of serum insulin like growth factor I (IGF-I), and an inappropriately high concentration of serum insulin like growth factor II (IGF-II). After resection of the tumour the growth hormone response to insulin induced hypoglycaemia and the IGF-I and IGF-II concentrations were normal. These data suggest that the hypoglycaemia was due to production of IGF-II by the tumour, causing increased glucose utilisation and an impaired growth hormone counterregulatory response to hypoglycaemia.

We have reported the case of a 69-year-old woman with a hugh benign fibrous tumor of the left pleura and hypoglycemic seizures. Increased preoperative levels of insulin-like growth factor (IGF II) were present; insulin level was low and plasma levels of somatomedin C were normal. After resection of the 2,400 gm tumor, blood sugar level has remained normal, and IGF II has fallen to normal limits. This appears to be the first reported case documenting elevated serum IGF II in association with a benign fibrous pleural tumor.

Two cases of hypoglycemiant pleural fibroma are reported: -- the first case, in a patient with sarcoidosis, was diagnosed following the onset of neuropsychic manifestations due to hypoglycemia; --the second case, much more atypical, was a patient with an enormous pleural tumor affecting cardiorespiratory function to such a degree that almost total incapacity ensued: the hypoglycemia was detected during routine pre-operative investigations. Various extrathoracic manifestations accompany these tumors: osteo-articular (present in 1 patient), and thyroidal (present in both cases). The various mechanisms proposed to explain the development of hypoglycemia in patients with certain extra-pancreatic tumors are reviewed.

A case of hypoglycemic coma and benign pleural mesothelioma is described. Serum insulin levels, as measured by insulin radioimmunoassay, were appropriately suppressed and consistent with hypoglycemia. Assay of the tumor showed insulin to be undectable. The mechanisms for hypoglycemia probably included increased glucose consumption by the tumor and, more important, the inhibition of lipolysis and hepatic gluconegenesis caused by tumor release of L-tryptophan and its metabolites and/or possibly nonsuppressible insulin-like activity, soluble in acid-ethanol(NSILA-s).