The biotype and genetic characteristics of an isolate of the cowpox virus causing infection in a child

The study included 138 patients operated on for endo-extracellular pituitary adenomas which extend both intracranially and into the structures of the base of the skull. Operations via transcranial and transsphenoidal access to various tumor sites were performed in 38 patients (a main group), while 100 patients (a control group) underwent one of these operations. Two-stage operations, followed by removal of the suprasellar and basal regions of a tumor, are expedient for enhancing the efficiency of surgical treatment, reducing the incidence of complications associated with traumatic attempts at removing tumor parts hard-to-reach by transcranial or transsphenoidal approaches, as well as at reducing the number of relapses. At the first stage of surgical treatment it is advisable to make an intervention via transcranial access especially in cases of complex configuration of the suprasellar part of a tumor. The recommended interval between transcranial and transsphenoidal surgeries is 3-5 months. Two-stage surgical treatment does not lead to significant structural changes and to the increased number of complications, and to higher mortality rates as compared to one-stage surgery (transcranial or transsphenoidal surgeries alone).     

Transsphenoidal microsurgery of pituitary macroadenomas with long-term follow-up results

The authors have reported on 108 patients with pituitary macroadenomas (measuring 2 cm in at least one diameter) who underwent 117 transsphenoidal operations and five craniotomies, and were followed for periods ranging from 6 months to 14 years. Vision improved in 90% of the patients. Gross total tumor removal with no evidence of residual tumor tissue demonstrable on the postoperative computerized tomography scan was accomplished in 41% of cases. However, gross total tumor removal is not synonymous with complete tumor removal. Endocrine cure was possible in 25% of prolactin-secreting and 20% of growth hormone-secreting adenomas. The incidence of recurrence was 12%, with the majority occurring from 4 to 8 years postoperatively. Both the tumors with suprasellar extension of more than 2 cm and the hard fibrotic tumors had a higher recurrence rate. Postoperative administration of radiation therapy has been associated with a significantly lower recurrence rate than when this therapy was withheld. Transsphenoidal surgery of pituitary macroadenomas confined to the extra-arachnoid space is associated with a relatively small number of complications. The operative technique used in this series is described.     

Manifestation of primary hyperthyroidism after pituitary adenomectomy: a case report

We report a 47-year-old Japanese man who presented with visual disturbance due to a pituitary tumor with suprasellar extension. The patient had mild secondary hypothyroidism preoperatively, and was started on administration of levothyroxine sodium immediately before transsphenoidal surgery. After the operation, levothyroxine sodium was continued for several months. Pathological examination of the surgical specimen, together with endocrinological investigation revealed that the suprasellar tumor was a FSH-producing pituitary adenoma. Since 3 months after the operation, he has developed muscle weakness and finger tremor. He was found to be thyrotoxicosis, and levothyroxine sodium was discontinued. Seven weeks after levothyroxine sodium was discontinued, thyrotoxicosis continued, with a positive thyrotropin binding inhibitory immunoglobulin (TBII) and a high diffuse 123I-uptake by the thyroid. He was started on thiamazole 30 mg/day. Although his thyroid dysfunction improved within 2 months, hyperthyroidism worsened repeatedly on attempts to discontinue thiamazole, and he required continuous treatment at 2.5 mg/day. Patients with occult autoimmune thyroiditis rarely progress to thyrotoxicosis after operations on other endocrine organs such as the adrenal or parathyroid gland. In patients with pituitary adenoma, thyroid function and thyroid-associated autoantibodies should be investigated pre- and post-operatively.     

Prolactin-secreting pituitary carcinoma with implants in the cheek pouch and metastases to the ovaries. A case report and literature review

BACKGROUND: Prolactin-secreting pituitary carcinomas are uncommon, locally destructive neoplasms that rarely metastasize outside the central nervous system. The authors report a case of a prolactin-secreting tumor that initially presented as the empty sella syndrome. Two recurrences along transsphenoidal surgery tracts in cheek pouches were followed by distant metastases later in the abdomen and pelvis. Only 10 previous cases of either extracranial or intracranial metastases from prolactin-secreting pituitary carcinomas have been reported. No metastases below the diaphragm have been reported previously. METHODS: The patient's cheek pouch implants, lymph node metastases, ovarian metastases, and uterine metastases were studied with prolactin-specific immunohistochemistry. RESULTS: Long term treatment with bromocriptine, several debulking surgeries, extensive local radiation therapy (external beam and proton beam), and cytotoxic chemotherapy had little impact. Tamoxifen, however, may have slowed tumor growth. CONCLUSION: Tamoxifen may have efficacy in the treatment of prolactin-secreting pituitary carcinomas.     

Postoperative sella: evaluation with fast spin echo T2-weighted high-resolution imaging

OBJECTIVE: The purpose of this study was to investigate the magnetic resonance features of the postoperative sella with fast spin echo (FSE) T2-weighted high-resolution imaging and to evaluate the benefits of the sequence using a follow-up magnetic resonance imaging protocol after transsphenoidal surgery. METHODS: Coronal spin echo (SE) T1-weighted and FSE T2-weighted images were prospectively obtained in 24 patients after surgery for pituitary adenomas. We observed the signals and the contour of normal structures, fluid collection, implanted materials, and mass lesions, including granulation tissue and adenoma. RESULTS: The pituitary gland was delineated in 51 of 59 FSE T2-weighted images, 90.2% of which presented clear boundaries. Whereas the gland was detected in 49 of 58 SE T1-weighted images, only 20.4% showed the boundaries. A mass lesion was identified in each of 12 patients with good resolution on FSE T2-weighted images. SE T1-weighted images detected mass lesions in 7 of 12 patients without distinctive boundaries. Contrast enhancement had little advantage in clarifying the boundaries between normal and abnormal structures. For the detection of mass lesions in the sella, the kappa values for interobserver agreement were 0.8 for FSE T2-weighted images and 0.25 for SE T1-weighted images. CONCLUSION: FSE T2-weighted imaging is a reliable method with which to assess the sella with sufficient resolution after transsphenoidal surgery. The combination of unenhanced SE T1-weighted and FSE T2-weighted images may reduce the use of contrast material after pituitary surgery.     

Hemorrhagic chondroid chordoma mimicking pituitary apoplexy

We describe a hemorrhagic chondroid chordoma involving the sella turcica with suprasellar extension. The CT and MRI appearances mimiked a hemorrhagic pituitary adenoma. Chondroid chordoma is a variant composed of elements of both chordoma and cartilaginous tissue. An uncommon bone neoplasm, located almost exclusively in the spheno-occipital region, it is usually not considered in the differential diagnosis of a tumor with acute hemorrhage in the sellar region. We discuss the clinical and radiological characteristics which may allow one to differentiate chondroid chordoma from other tumors of this area.     

Long-term preoperative management of thyrotropin-secreting pituitary adenoma with octreotide

Thyrotropin (TSH)-secreting pituitary adenomas are the less frequent form of presentation of pituitary tumors. Selective transsphenoidal surgical resection of the tumor is the treatment of choice. Given that native somatostatin inhibits TSH secretion, treatment with somatostatin analogues has been recently employed in patients with unresectable tumors or after surgery. We report on the case of a 58 year-old man with a TSH-secreting pituitary adenoma who was treated with octreotide for long-term before neurosurgery. The patient was referred to us because of a pituitary mass on CT scanning. Hormonal evaluation resulted in hyperthyroidism with high serum TSH concentrations. Serum alpha subunit concentration was elevated and TSH response to exogenous TRH stimulation was absent. Magnetic resonance imaging of the hypothalamic-pituitary area confirmed the presence of a pituitary mass (2.0 by 1.8 by 1.7 cm). Acutely administered subcutaneous octreotide (100 microg) was followed by a reduction of the serum TSH concentrations. Therefore, the patient received octreotide, 100 microg three times daily for 12 months. At first month after beginning therapy serum TSH, free thyroxine, total triiodothyronine, and alpha subunit concentrations were normalized and persisted into the normal range for the next 11 months. On the other hand, a shrinkage of the tumor mass (1.6 by 1.7 by 1.4 cm) was noted after 6 months of octreotide therapy, however, its volume did not modify in the following next months. Then, the tumor was removed by transsphenoidal surgery and the diagnosis was confirmed by immunohistochemical staining. This case demonstrates that long-term treatment with octreotide gave rise to a normalization of the thyroid function and a reduction of the tumor volume before surgery. This clinical observation suggests that octreotide therapy might be useful in preparation for pituitary surgery in patients with TSH-secreting pituitary adenomas.     

Fusiform dilatations of the internal carotid artery following surgery for pediatric suprasellar tumors

Fusiform dilatations of the internal carotid artery (FDCA) represent a vascular complication following surgery for suprasellar tumors in children. In a long-term follow-up of 62 children we identified 7 children (11.3%) with a FDCA. In all children the FDCA was present within 15 months following surgery. It was not related to radiotherapy or a distinct histology. In 3 children the FDCA remained unchanged during the follow-up, in 3 children there was a progression and 1 child revealed a regression within 6 months. Clinically the FDCA was inapparent in all cases and not treated. In a follow-up study of an adult population who underwent surgery for suprasellar tumors no case of FDCA was encountered. Potential pathomechanisms and indications for treatment are discussed.     

Reassessment of the role of radiation therapy in the treatment of endocrine-inactive pituitary macroadenomas

OBJECTIVE: This prospective clinical trial was undertaken to assess the rate of tumor recurrence in patients with endocrine-inactive pituitary macroadenomas who underwent gross total surgical resection of their tumors and did not receive adjuvant radiotherapy. METHODS: Between December 1987 and July 1994, 45 patients with endocrine-inactive pituitary macroadenomas underwent transsphenoidal surgery. In 38 (84%) of these patients, gross total surgical resection was achieved and was confirmed by postoperative magnetic resonance imaging (n = 37) or computed tomography (n = 1). After receiving counseling from the neurosurgeon concerning the risks and benefits of radiation therapy, 32 of the 38 patients elected not to receive adjuvant radiotherapy. Patients were followed through March 1998 with radiographic imaging obtained every 6 months for the first 2 years, annually for postoperative Years 3 and 4, and then every 2 to 3 years thereafter. The study end point was defined as radiographic tumor recurrence or patient death. RESULTS: The mean follow-up duration for the study group was 5.5 years. During that time, 2 of 32 (6%) patients developed recurrence, at 18 and 24 months, respectively, after initial surgery. Both were successfully treated using radiation therapy, with one requiring additional surgery. Three additional patients died as a result of unrelated causes 9, 12, and 49 months, respectively, after initial surgery. Immunocytochemical analysis revealed 66% of the tumors to be weak gonadotroph cell adenomas, 22% to be null cell adenomas, 9% to be silent prolactinomas, and 3% to be silent corticotroph cell adenomas. CONCLUSION: This study demonstrates a 6% 5-year recurrence rate in patients with endocrine-inactive pituitary macroadenomas treated using gross total surgical resection alone. Reserving radiation therapy for the infrequent patient with recurrence and sparing the majority of patients the associated risks inherent in its use seems reasonable.     

Unusual approaches to hypophyseal adenomas

For pituitary adenomas surgery, rhinoseptal transsphenoidal approach is used in 98 to 99% of the cases. Although this approach is fitting for microadenomas and the majority of macroadenomas, some of them develop extensions in the nasal fossas, the posterior cranial fossa, the suprasellar region, or into the cavernous sinus and will require other approaches. For the superior routes, the frontopterional approach gives good control of the suprasellar region, the anterior and middle base of the skull. The tumor dissection is performed inside the concavity of the chiasm and between the internal carotid artery and the optic nerve (optico-carotid approach). The frontopterional approach is used for superolateral extensions, especially in the lateral fissure. The bifrontal basal inter hemispheric approach, through a medial frontal bone flap tangential to the base, gives a good route to the suprasellar region and behind the dorsum, and also for tumors extended in the third ventricle in case of prefixed chiasm. For the inferior routes, the participation of ENT or craniofacial surgeons is a great help. The transfacial or transethmoidal approach performs a hollowing of the nasal fossas and gives a large interorbital tunnel adapted for tumors extended in the rhinopharynx and the ethmoid. The Le Fort I maxillary osteotomy offers also a large approach for adenomas extending in the rhinopharynx. The transcavernous approach from Dolenc, for adenomas progressing in the cavernous sinus requires a long and difficult procedure. The progression of some adenomas in many directions may require a combined approach in one or two procedures.     

Symptom resolution, tumor control, and side effects following postoperative radiotherapy for pituitary macroadenomas

This study reports the outcome of 70 patients who were treated by a consistent treatment plan of surgery and postoperative radiotherapy (RT) for pituitary macroadenomas in the modern era [computed tomographic scan or magnetic resonance imaging (MRI), dopamine agonist therapy (DA) added as indicated, and immunohistochemical staining]. Sixty-two patients underwent transsphenoidal surgery (vs. transcranial surgery) and 61 received 45-Gy/25 fractions postoperatively (vs. other dose fractionation schemes). Twenty-four patients received DA for prolactin-secreting tumors. With a median follow-up of 8 years (range 2-15), 68 patients have experienced continuous control of their tumors. Most symptoms related to mass effect abated, while physiologic symptoms such as amenorrhea from markedly elevated prolactin levels tended to persist. Treatment-induced hypopituitarism occurred in 42% of the patients at risk. No patients in this series have died as a result of their pituitary tumor. No gross neuropsychologic dysfunction after treatment has been noted. While it is possible at this time with serial MRI to withhold postoperative RT and observe some patients who have had a "gross total" resection of a macroadenoma, the therapeutic ratio for surgery and adjuvant radiotherapy for patients with nonfunctional tumors as well as select patients with secretory macroadenomas is favorable.     

The accuracy of CT and MR evaluation of the sella turcica for detection of adrenocorticotropic hormone-secreting adenomas in Cushing disease

PURPOSE: To document the accuracy of CT and MR of the sella turcica for detecting adrenocorticotropic hormone-secreting adenomas in Cushing disease. METHODS: The radiologic findings of the sella turcica prior to transsphenoidal surgery are reviewed in 141 patients who had biochemical evidence of pituitary-dependent Cushing disease. Axial thin-collimation CT scans with sagittal and coronal reformations before and after contrast enhancement were obtained in 125 patients. Seventy-eight patients had MR examinations with a 1.5-T superconducting magnet. In 11 of the patients gadolinium-enhanced MR scans were also obtained. The preoperative interpretation of the imaging studies was correlated with the surgical findings and patients follow-up. RESULTS: The sella turcica was enlarged in 43 cases (30%). In 125 patients reformatted or direct coronal thin-collimation CT scans were available. Seventy-eight of the patients had MR. In the 12 patients with pituitary macroadenomas, the accuracy of CT (n = 10) and MR (n = 10) in respect to detection of the lesion was 100%. Of the 98 microadenomas assessed by CT, 47 (48%) were directly depicted as distinct hypodense lesions. In only 31 of 73 cases (42%), however, could CT predict the precise anatomic location and extent of the lesions. Only patients in whom the hypercortisolism was corrected by later surgery were considered for the correlation analysis. Of the 52 microadenomas assessed by MR, 28 (53%) were directly depicted as distinct lesions of reduced signal intensity on T1-weighted images, and in only 21 of 41 cases (52%) did MR show good correlation to the surgical findings. Some degree of partially empty sella was found in 22% of the patients. CONCLUSIONS: Although both the sensitivity and the diagnostic accuracy of imaging methods of the sella turcica have been considerably improved in comparison with previous reports, they still provide only a minor contribution to the diagnosis and differential diagnosis of Cushing syndrome.     

Surgical treatment of craniopharyngiomas: experience with 168 patients

OBJECT: The goal of this study was to assess the outcome of surgical management in 168 consecutive patients harboring craniopharyngiomas treated between January 1983 and April 1997. METHODS: In 148 patients undergoing initial (primary) surgery, the pterional approach was most frequently used (39.2%), followed by the transsphenoidal approach (23.6%). For large retrochiasmatic craniopharyngiomas, the bifrontal interhemispheric approach was used increasingly over the pterional approach and led to improved surgical results. Total tumor removal was accomplished in 45.7% of transcranial and 85.7% of transsphenoidal procedures. The main reasons for incomplete removal were attachment to and/or infiltration of the hypothalamus, major calcifications, and attachment to vascular structures. The success rate in total tumor removal was inferior in the cases of tumor recurrence. The operative mortality rate in transcranial surgery was 1.1% in primary cases and 10.5% in cases of tumor recurrence. No patient died in the group that underwent transsphenoidal surgery. The rate of recurrence-free survival after total removal was 86.9% at 5 years and 81.3% at 10 years. In contrast, the 5-year recurrence-free survival rate was only 48.8% after subtotal removal and 41.5% after partial removal. Following primary surgery, the actuarial survival rate was 92.7% at 10 years, with the best results after complete tumor removal. At last follow up, 117 (79%) of 148 patients who underwent primary surgery were independent and without impairment. CONCLUSIONS: Total tumor removal while avoiding hazardous intraoperative manipulation provides favorable early results and a high rate of long-term control in craniopharyngiomas.     

The radiology of transsphenoidal hypophysectomy: a review of 100 cases

This report describing the radiology of transsphenoidal hypophysectomy based on a review of 100 consecutive surgical procedures. Preoperative laminographic evaluation of the sphenoid sinus is an important aid in planning the most direct surgical approach to the pituitary. It is also useful in defining the many anatomic structures that may be injured inadvertently at the time of surgery. Intraoperative radiography or fluoroscopy is helpful in identifying the sella floor and as an aid in preventing loss of orientation within a capacious sinus. Various changes occur within the sphenoid sinus following surgery, some transient and others persistent. The surgical defect is usually difficult to identify on routine roentgenograms but is clearly visible on lateral laminography. A persistent soft tissue mass within the sinus is usually a manifestation of fascia and fat placed as a seal within the sinus.     

A catalytic antibody that accelerates the hydrolysis of carbonate esters. Prediction of the binding-site structure of the substrate

A recurrent craniopharyngioma associated with moyamoya vessels was successfully treated by partial removal of the tumor via the transsphenoidal approach followed by gamma-knife radiosurgery. This 19-year-old man was first treated by partial tumor removal and radiotherapy (54Gy) at the age of 6 years. Growth hormone and human chorionic gonadotropin were given from the ages of 13 to 18 years. At ag 17 years, follow-up magnetic resonance imaging (MRI) revealed regrowth of the tumor. At the age of 19 years, he was readmitted for treatment of the enlarging remnant tumor. Neurological examination revealed bilateral blindness. MRI showed marked suprasellar, sphenoidal and bilateral cavernous sinus extension of the tumor. Angiography revealed stenosis of the right internal carotid artery and the M1 and A1 segments of the right cerebral arteries, as well as occlusion of the C3 segment of the left internal carotid artery. There were vault and ethmoidal moyamoya vessels. The patient underwent tumor removal via the transsphenoidal approach, instead of craniotomy, to avoid injury to the transdural anastomosis. The intrasellar solid tumor was partially removed. The tumor was then irradiated by the gamma knife. MRI 15 months after the treatment showed marked reduction of the tumor. The pathogenesis of the moyamoya phenomenon and the choice of the treatment in this patient are discussed.     

Extrapontine myelinolysis and behavioral change after transsphenoidal pituitary surgery: case report

OBJECTIVE AND IMPORTANCE: Rapid correction of hyponatremia is considered the usual cause of central pontine myelinolysis and extrapontine myelinolysis. Little has been reported about mental changes associated with this disorder or its occurrence after transsphenoidal surgery. CLINICAL PRESENTATION: A 24-year-old woman suddenly developed markedly abnormal behavior associated with rapid correction of hyponatremia 11 days after undergoing transsphenoidal surgery for a prolactin-secreting pituitary adenoma. INTERVENTION: Magnetic resonance imaging and positron emission tomography with 18F-fluorodeoxyglucose showed bilateral caudate nuclei and putaminal lesions. Gradual, complete clinical resolution preceded the resolution that was revealed by magnetic resonance imaging. CONCLUSION: We emphasize the importance of cautious correction with frequent electrolyte determinations and attention to behavioral changes in the management of delayed hyponatremia after pituitary tumor surgery.     

Long-term pharmacological kindling increases in vitro release of IR-Met and IR-Leu-enkephalin from amygdala

Preoperative therapy with octreotide, a long-acting somatostatin analog, suppresses GH hypersecretion, shrinks GH-producing tumors and leads to an improvement in subsequent surgical remission in acromegalic patients. A continuous infusion of octreotide has demonstrated more persistent suppression of GH secretion than intermittent injections, and only a few studies were reported on the effect of the tumor shrinkage with a continuous infusion of a small dose of octreotide. We therefore investigated the preoperative effects of small doses of octreotide (120-240 micrograms/day) administered continuously (with a subcutaneous infusion pump) over a short period (2 or 4 weeks) in nine untreated acromegalic patients. Octreotide therapy resulted in suppression of serum GH and IGF-1 concentrations in 8 out of 9 patients and reduction in pituitary tumor size measured by MRI in all patients (by 7.9 to 38.5%). In particular, considerable reduction in tumor size (more than 20%) occurred in 6 of 9 patients. In three patients assessed serially throughout the preoperative period, reduction in tumor size was noted within only one week after the start of octreotide therapy and reduction rate more than 20% was obtained within the first two weeks. In one patient, suprasellar tumor expansion totally disappeared after such therapy. Our results indicate that short-term continuous subcutaneous infusion of a small dose of octreotide results in not only inhibition of GH hypersecretion but also shrinkage of tumor size prior to surgery.     

New standards for the assessment of sella turcica volume in children

New standards for the assessment of sella turcica volume were derived from studies in normal children. Use of these standards facilitates the diagnostic evaluation of children with short stature, since many patients with idiopathic hypopituitarism have abnormally small sella turcica volumes. The sellar volume should be estimated early in the evaluation of the short child and, if found to be small, should serve as a stimulus for prompt, thorough evaluation of pituitary function.     

Bromocriptine therapy for "nonfunctioning" pituitary tumors

Bromocriptine therapy may cause regression of prolactinomas, but its effect on nonsecretory pituitary tumors is uncertain. Conventional treatment for such "functionless" tumors is surgery and/or radiotherapy, but recurrences pose a therapeutic dilemma. We describe a patient with such a tumor treated by surgery and radiotherapy who presented with recurrent disease 14 days later. On treatment with bromocriptine, 20 mg daily for 25 months, the intrasellar tumor recurrence had diminished in size and a suprasellar extension had almost disappeared. Bromocriptine therapy may therefore benefit some patients with nonsecretory pituitary tumors considered unsuitable for surgery or radiotherapy.     

Treatment of vancomycin-resistant Enterococcus faecium infections with an investigational streptogramin antibiotic (quinupristin/dalfopristin): a report of fifteen cases

OBJECTIVE: Previous studies of surgical treatment for acromegaly have used varied criteria for 'cure', but elevated GH levels are considered to be associated with continuing disease activity. We wished to analyse the results of transsphenoidal pituitary surgery for acromegaly and assess the longer-term outcome for patients not offered further treatment when post-operative levels of GH < 5 mU/l were achieved. DESIGN: We studied a retrospective group of patients who underwent transsphenoidal surgery for acromegaly at St Bartholomew's Hospital between 1985 and 1993. PATIENTS: One hundred consecutive patients (53 male, mean age 46 years, range 18-68 years) undergoing transsphenoidal surgery for acromegaly were assessed. The patients were followed for a mean of 3.8 years (range 0.5-8 years) after operation. MEASUREMENTS: GH levels are represented as a mean value from a four-point day curve taken at 0830, 1300, 1700 and 1900 h. ACTH reserve was assessed basally and, if this was normal, with the insulin tolerance or glucagon tests. TSH, T4, PRL, LH, FSH, testosterone or oestradiol and plasma and urine osmolality were also measured. RESULTS: Post-operatively, 42% of patients achieved a mean GH level of < 5 mU/l. The success of surgery was related to the preoperative GH level; 65% of the patients with preoperative GH levels < 20 mU/l but only 18% of the patients with GH levels > 100 mU/l achieved post-operative GH values < 5 mU/l. In addition, tumour size influenced the outcome of surgery with 61% of patients with a microadenoma but only 23% of patients with a macroadenoma achieving post-operative GH levels of < 5 mU/l. Of the 42 patients considered in remission post-operatively (mean GH < 5 mU/l), 32 were available for long-term follow-up and were not offered any further treatment: only one of these has shown evidence of mild biochemical recurrence after a mean follow-up of 3.8 years (range 0.5-8). There were no peri-operative deaths. Two patients required surgical repair for CSF leaks and there were eight documented cases of meningitis. Permanent diabetes insipidus was noted in eight patients post-operatively. New anterior pituitary deficiency occurred in 21% of patients following surgery; 73% had unaltered pituitary function and in 6% recovery of partial hypopituitarism was noted. CONCLUSIONS: The stated outcome of surgery depends on the criteria adopted. Safe GH levels (mean levels < 5 mU/l) can be achieved in 42% of an unselected series of patients with acromegaly and if the tumour is a microadenoma this figure rises to 61%. Based on the current evidence it is safe not to offer further treatment to those patients in whom post-operative GH < 5 mU/l are achieved.