Long-term surgical outcome in 16 patients with thyrotropin pituitary adenoma

Thyrotropin-secreting pituitary tumours: significance of “atypical adenomas” in a series of 10 patients and association with Hashimoto thyroiditis as a cause of delay in diagnosis

Background:

Thyrotropin-secreting adenomas (TSH-As) are rare and, according to the World Health Organization criteria (WHO 2004), a significant proportion of them present features of atypical adenomas at the time of diagnosis.

Aims:

To determine the frequency of “atypical adenomas” and the significance of this definition as regards follow-up. To investigate their possible association with Hashimoto thyroiditis, leading to a delay in diagnosis.

Methods:

Case notes for patients who underwent trans-sphenoidal surgery between 1992 and 2006 were retrieved. Follow-up ranged from 6 to 180 months.

Results:

Ten cases of TSH-As out of 908 pituitary adenomas were selected. Before surgery, eight patients had hyperthyroidism, one was euthyroid and another one showed hypothyroidism associated with Hashimoto thyroiditis. All cases were macroadenomas; six of them were invasive. Three cases met the criteria for classification as atypical. In none of the cases, including the three “atypical adenomas”, were clinical or radiological signs of recurrence observed.

Conclusions:

The three cases with features of atypical adenoma did not recur or metastasise, suggesting that, at least in the present series, a strict relationship between the morphological criteria for diagnosing atypical adenomas and biological behaviour may be sometimes lacking. Furthermore, the casual association of TSH-As with Hashimoto thyroiditis may led to an adjunctive delay in diagnosis, because of low thyroid hormone levels.

Spine patient outcomes research trial: radiographic predictors of clinical outcomes after operative or nonoperative treatment of degenerative spondylolisthesis

STUDY DESIGN

Subgroup analyses according to treatment received.

OBJECTIVE

To evaluate whether baseline radiographic findings predicted outcomes in patients with degenerative spondylolisthesis.

SUMMARY OF BACKGROUND DATA

The spine patient outcomes research trial combined randomized and observational DS cohorts.

METHODS

The Meyerding listhesis grade was determined on the neutral radiograph (n = 222). Patients were classified as having low disc height if disc height was less than 5 mm. Flexion-extension radiographs (n = 185) were evaluated for mobility. Those with greater than 10 degrees rotation or 4 mm translation were considered hypermobile. Changes in outcome measures were compared between listhesis (grade 1 vs. grade 2), disc height (low vs. normal), and mobility (stable vs. hypermobile) groups using longitudinal regression models adjusted for potential confounders. Outcome measures included SF-36 bodily pain and physical function scales, oswestry disability index (ODI), stenosis bothersomeness index, and low back pain bothersomeness scale.

RESULTS

Overall, 86% had a grade 1 listhesis, 78% had normal disc height, and 73% were stable. Baseline symptom severity was similar between groups. Overall, surgery patients improved more than patients treated nonoperatively. At 1 year, outcomes were similar in surgery patients across listhesis, disc height, and mobility groups (ODI: grade 1 -23.7 vs. grade 2 -23.3, P = 0.90; normal disc height -23.5 vs. low disc height -21.9, P = 0.66; stable -21.6 vs. hypermobile -25.2, P = 0.30). Among those treated nonoperatively, grade 1 patients improved more than grade 2 patients (bodily pain + 13.1 vs. -4.9, P = 0.019; ODI -8.0 vs. + 4.8, P = 0.010 at 1 year), and hypermobile patients improved more than stable patients (ODI -15.2 vs. -6.6, P = 0.041; stenosis bothersomeness index -7.8 vs. -2.7, P = 0.002 at 1 year).

DISCUSSION

Regardless of listhesis grade, disc height or mobility, patients who had surgery improved more than those treated nonoperatively. These differences were due, in part, to differences in nonoperative outcomes, which were better in patients classified as grade 1 or hypermobile.

Composite pituitary adenoma and craniopharyngioma?: an unusual sellar neoplasm with divergent differentiation

We report a young man who presented with atrial fibrillation and was subsequently found to have a markedly elevated serum thyroid stimulating hormone level and a solid, noncalcified intrasellar mass on imaging. The patient was treated with thyroid radioablation and hormone replacement and followed for 7 years, during which time the tumor grew to 4.6 cm. He had no visual disturbances or other hormonal symptoms. At transsphenoidal surgery, a tumor consisting of a pituitary adenoma and adamantinomatous craniopharyngiomalike components was resected. Both components were closely intermingled, but there was no evidence of an intermediate morphologic phenotype. Immunohistochemically, the adenoma was not only positive for beta-thyroid stimulating hormone, alpha subunit, and pituitary transcription factor 1, but also stained for beta-follicle stimulating hormone, steroidogenic factor-1, adrenocorticotropic hormone, and pituitary-restricted transcription factor (Tpit), exhibiting an unusual plurihormonal profile. The craniopharyngiomalike component showed immunoreactivity for steroidogenic factor-1, one of the pituitary transcription factors. This lesion may represent an unusual composite tumor attributable to divergent differentiation of a common precursor. Alternatively, it may be viewed as a pituitary adenoma showing metaplastic change analogous to the development of squamous cell nests of the pars tuberalis from adenohypophyseal endocrine cells.

Multiple endocrine neoplasia type 1-associated thyrotropin-producing pituitary carcinoma: report of a probable de novo example

Pituitary carcinomas are exceedingly rare. At present, the sole diagnostic criterion is metastatic spread, either craniospinal or systemic. There is no agreement on a histologic, immunohistochemical, and/or ultrastructural definition. We report a clinically and morphologically well-documented example of pituitary thyrotropin cell carcinoma in a man with multiple endocrine neoplasia type 1 syndrome. The tumor produced thyrotropin, alpha-subunit, and prolactin and, through electron microscopy, was found to consist solely of Thyrotroph cells. Over a protracted course, craniospinal and systemic metastases were noted. The primary and metastatic deposits of this aggressive tumor were studied. To our knowledge, this tumor is the first reported case of thyrotropin cell carcinoma occurring in association with the multiple endocrine neoplasia type 1 syndrome. The literature regarding thyrotropin carcinomas is reviewed. Based on the study of several biopsies during disease progression, we believe that the carcinoma originated de novo without an intermediary adenoma phase.

Minimum four-year follow-up of spinal stenosis with degenerative spondylolisthesis treated with decompression and dynamic stabilization

STUDY DESIGN

Prospective clinical study.

OBJECTIVE

To test whether posterior dynamic stabilization in situ with Dynesys (Zimmer Spine, Minneapolis, MN) can maintain enough stability to prevent progression of spondylolisthesis in long-term follow-up.

SUMMARY OF BACKGROUND DATA

In spinal stenosis with degenerative spondylolisthesis, decompression and fusion are widely recommended. However, drawbacks of fusion remain length of surgery, blood loss, possible adjacent segment disease, errant instrumentation, nonunion, and pain at the bone donor site. The Dynesys system was introduced to stabilize the spine without adding bone graft for fusion. Excellent 2 years results have been reported.

METHODS

Twenty-six consecutive patients (mean age, 71 years) with symptomatic lumbar spinal stenosis and degenerative spondylolisthesis underwent interlaminar decompression and stabilization with Dynesys. Patients were evaluated clinically and radiologically after a minimum follow-up of 4 years.

RESULTS

Nineteen of 26 patients could be evaluated with a mean follow-up of 52 months (range, 48-57 months). Pain on VAS and walking distance improved significantly (P < 0.001) at 2 years and remained unchanged at 4 years follow-up. Radiographically, spondylolisthesis did not progress and the motion segments remained stable, even in the 3 patients who showed slight screw-loosening at 2 and 4 years follow-up. One patient showed screw breakage with low back pain and motion at the instrumented level in flexion/extension views. At 4 years follow-up, 47% of the patients showed some degeneration at adjacent levels. Overall, patient satisfaction remained high as 95% would undergo the same procedure again.

CONCLUSION

In elderly patients with spinal stenosis and degenerative spondylolisthesis, decompression and dynamic stabilization lead to excellent clinical and radiologic results. It maintains enough stability to prevent progression of spondylolisthesis. Because no bone grafting is necessary, donor site morbidity, which is one of the main drawbacks of fusion is eliminated. However, the degenerative disease still is progressive and degeneration at adjacent motion segments remains a problem.

Thyroid-stimulating hormone pituitary adenomas

Object

Thyroid-stimulating hormone (TSH)–secreting pituitary adenomas are rare, representing < 2% of all pituitary adenomas.

Methods

The authors conducted a retrospective analysis of patients with TSH-secreting or clinically silent TSH-immunostaining pituitary tumors among all pituitary adenomas followed at their institution between 1987 and 2003. Patient records, including clinical, imaging, and pathological and surgical characteristics were reviewed. Twenty-one patients (6 women and 15 men; mean age 46 years, range 26–73 years) were identified. Of these, 10 patients had a history of clinical hyperthyroidism, of whom 7 had undergone ablative thyroid procedures (thyroid surgery/131I ablation) prior to the diagnosis of pituitary adenoma. Ten patients had elevated TSH preoperatively. Seven patients presented with headache, and 8 presented with visual field defects. All patients underwent imaging, of which 19 were available for imaging review. Sixteen patients had macroadenomas.

Results

Of the 21 patients, 18 underwent transsphenoidal surgery at the authors' institution, 2 patients underwent transsphenoidal surgery at another facility, and 1 was treated medically. Patients with TSH-secreting tumors were defined as in remission after surgery if they had no residual adenoma on imaging and had biochemical evidence of hypo-or euthyroidism. Patients with TSH-immunostaining tumors were considered in remission if they had no residual tumor. Of these 18 patients, 9 (50%) were in remission following surgery. Seven patients had residual tumor; 2 of these patients underwent further transsphenoidal resection, 1 underwent a craniotomy, and 4 underwent postoperative radiation therapy (2 conventional radiation therapy, 1 Gamma Knife surgery, and 1 had both types of radiation treatment). Two patients had persistently elevated TSH levels despite the lack of evidence of residual tumor. On pathological analysis and immunostaining of the surgical specimen, 17 patients had samples that stained positively for TSH, 8 for α-subunit, 10 for growth hormone, 7 for prolactin, 2 for adrenocorticotrophic hormone, and 1 for follicle-stimulating hormone/luteinizing hormone. Eleven patients (61%) ultimately required thyroid hormone replacement therapy, and 5 (24%) required additional pituitary hormone replacement. Of these, 2 patients required treatment for new anterior pituitary dysfunction as a complication of surgery, and 2 patients with preoperative partial anterior pituitary dysfunction developed complete panhypopituitarism. One patient had transient diabetes insipidus. The remainder had no change in pituitary function from their preoperative state.

Conclusions

Thyroid-stimulating hormone–secreting pituitary lesions are often delayed in diagnosis, are frequently macroadenomas and plurihormonal in terms of their pathological characteristics, have a heterogeneous clinical picture, and are difficult to treat. An experienced team approach will optimize results in the management of these uncommon lesions.

Degenerative lumbar spondylolisthesis: trends in management

Degenerative spondylolisthesis with spinal stenosis is common in elderly patients. When symptomatic, the resultant neurogenic claudication often leads to a diminished quality of life. A nonsurgical approach is an appropriate first step. Maximizing the chance of a solid arthrodesis improves the possibility of a successful long-term outcome. Treatment of this pathology has evolved over the past twenty years with the publication of numerous prospective randomized trials assessing the influence of fusion and instrumentation following decompression. Current prospective trials have evaluated the use of bone morphogenetic proteins as a substitute for autogenous bone graft. Recently, soft-tissue stabilization devices have been advocated as an alternative to fusion. Clinicians should critically evaluate these newer technologies and exercise caution regarding their use until controlled long-term trials are completed.

Dynamic neutralization of the lumbar spine after microsurgical decompression in acquired lumbar spinal stenosis and segmental instability

STUDY DESIGN

Prospective clinical study.

OBJECTIVE

To report the outcome, radiologic findings, and complications in patients undergoing microsurgical radicular decompression and implantation of Dynesys (Zimmer Spine, Münsingen, Switzerland).

SUMMARY OF BACKGROUND DATA

The currently available peer-reviewed English-language medical literature addressing the use of the dynamic stabilization systems is limited. Indications, clinical results, and implant failure of Dynesys after microsurgical decompression are still controversial.

METHODS AND RESULTS

This study included a total of 37 consecutive patients (mean age 58 years) presenting with acquired lumbar stenosis, signs of segmental instability, and degenerative disc disease underwent lumbar microsurgical decompression and implantation of Dynesys in 1 (n = 11), 2 (n = 17), 3 (n = 9), and 4 segments (n = 1). One patient was lost to follow-up. Lumbar and radicular pain was present in 33 patients (92%). Clinical evaluation included visual analogue scale (leg and back), distribution and severity of pain (%), Prolo Functional and Economic Status, Stauffer Coventry Scale, patient's self evaluation, and radiologic assessment preoperative and postoperative at 3 and 12 months. Leg and back pain (visual analogue scale) improved at 12 months from 8.4 +/- 2.1 to 3.1 +/- 1.4 and from 6.7 +/- 2.8 to 4 +/- 2.8, respectively. Overall pain severity improved due to reduction of radicular pain from 59.2% to 27.3% after microsurgical decompression. Meanwhile, lumbar pain deteriorated from 40.8% to 47.8%. Twenty-seven percent (patient's self-evaluation) and 29.7% (Stauffer Coventry Scale) of the patients described a fair or poor outcome. Moreover, 51% and 54% of the patients had a Prolo Economic Status and Prolo Functional of 4 or 5, respectively. Complications included 4 broken and 2 misplaced screws from a total of 224 screws implanted, 2 loosen systems, and 1 cerebrospinal fistula. At 1-year, a total of 7 patients (19%) required surgical revision.

CONCLUSION

The reported biomechanical principles of Dynesys do not reflect advantages in outcome compared with none or others stabilization systems after microsurgical radicular decompression reported in the literature.

A case of atypical thyrotroph cell adenoma, which re-grew within 3 months after surgery and required multimodal treatment

OBJECTIVE AND IMPORTANCE

Thyrotroph cell adenoma accounts for only 1% of all pituitary adenomas. This tumor is tough and firm because of significant interstitial fibrosis, and is difficult to remove. Atypical adenoma has an aggressive biological character, invades the surrounding structures, and grows rapidly. Atypical thyrotroph cell adenoma is extremely rare.

CLINICAL PRESENTATION

A 32-year-old man presented with hyperthyroidism and bitemporal hemianopsia. Head magnetic resonance imaging revealed a large sellar tumor compressing the optic chiasma and invading the left cavernous sinus.

INTERVENTION

Transsphenoidal surgery was performed and subtotal removal was achieved. Histological examination showed atypical thyrotroph cell adenoma. Gamma knife surgery was planned, but the tumor re-grew within 3 months, and reattached to the optic chiasma. Second transcranial surgery failed to remove residual tumor behind the pituitary stalk. Conventional irradiation followed by octreotide administration resulted in decreased tumor size and stable euthyroidism. The tumor has been controlled for 22 months since first surgery and diagnosis.

CONCLUSION

Atypical thyrotroph cell adenoma has an aggressive biological character and grows rapidly. Multimodal treatment including medication and radiotherapy is required.

Dynamic stabilization in addition to decompression for lumbar spinal stenosis with degenerative spondylolisthesis

STUDY DESIGN

Prospective clinical study.

OBJECTIVE

To test whether elastic stabilization with the Dynesys system (Zimmer Spine, Minneapolis, MN) provides enough stability to prevent further progression of spondylolisthesis as well as instability after decompression for spinal stenosis with degenerative spondylolisthesis.

SUMMARY OF BACKGROUND DATA

In spinal stenosis with degenerative spondylolisthesis, decompression and fusion is widely recommended. However, patients have donor site pain. In 1994, a dynamic transpedicular system (Dynesys) was introduced to the market, stating that stabilization is possible without bone grafting.

METHODS

A total of 26 patients (mean age 71 years) with lumbar spinal stenosis and degenerative spondylolisthesis underwent interlaminar decompression and dynamic stabilization with the Dynesys system. Minimum follow-up was 2 years. Operative data, clinical outcome, and plain and flexion/extension radiographs were obtained and compared to preoperative and postoperative data.

RESULTS

Mean leg pain decreased significantly (P < 0.01), and mean walking distance improved significantly to more than 1000 m (P < 0.01). There were 5 patients (21%) who still had some claudication. A total of 21 patients (87.5%) would undergo the same procedure again. Radiographically, no significant progression of spondylolisthesis could be detected. The implant failure rate was 17%, and none of them were clinically symptomatic.

CONCLUSIONS

In elderly patients with spinal stenosis with degenerative spondylolisthesis, dynamic stabilization with the Dynesys system in addition to decompression leads to similar clinical results as seen in established protocols using decompression and fusion with pedicle screws. It maintains enough stability to prevent further progression of spondylolisthesis or instability. With the Dynesys system, no bone grafting is necessary, therefore, donor site morbidity can be avoided.

TSH adenomas

Thyrotropin (TSH) adenomas are uncommon tumors of the anterior pituitary. Clinically, they may present with hyperthyroidism, hypothyroidism, hypopituitarism, or visual loss. Proper diagnosis requires appropriate neuroendocrine evaluation. Although transsphenoidal surgery remains the first-line treatment, adjuvant medical therapy is frequently required for these often invasive tumors. Radiotherapy or radiosurgery should be considered for those patients with persistent TSH hypersecretion following surgery and medical therapy. The clinical evaluation and treatment algorithm for patients with TSH adenomas is discussed.

Minimally invasive procedures for the treatment of failed back surgery syndrome

Failed back surgery syndrome has become unfortunately a common clinical entity. FBSS does not have one specific treatment because it does not have one specific cause. Some features are shared with chronic low back pain (CLBP) and some pathological processes are specific. Both pathologies are leading causes of disability in the industrialized world and costly medical and surgical treatments are continuously used despite their limited efficacy. Nonetheless, evidence based practice guidelines are systematically developed. In this chapter we cautiously review the vast, complex and at times contradictory literature regarding the treatment of FBSS. Interventional Pain literature suggests that there is moderate evidence (small randomized or non randomized or single group or matched case controlled studies) for medial branch neurotomy and limited evidence (non experimental one or more center studies) for intra-discal treatments in mechanical low back pain. There is moderate evidence for the use of transforaminal epidural steroid injections, lumbar percutaneous adhesiolysis and spinal endoscopy for painful lumbar radiculopathy and spinal cord stimulation and intrathecal pumps mostly after spinal surgery. In reality there is no gold standard for the treatment of FBSS but, these results seem promising.

Degenerative spondylolisthesis: review of current trends and controversies

STUDY DESIGN

A literature-based review.

OBJECTIVES

To review management and controversies and to present authors recommendations.

SUMMARY OF BACKGROUND DATA

There is considerable controversy regarding indication for surgery, role for decompression alone, and decompression with fusion with or without instrumentation.

METHODS

Review of English language medical literature.

RESULTS

The condition may stabilize itself with the collapse of the disc spaces and osteophytes but may continue to progress in nearly a third of the cases. It may cause predominantly back pain due to segmental instability, or radicular pain/neurogenic claudication secondary to root entrapment or spinal stenosis. When conservative treatment fails, the mainstay of surgical treatment is decompressive laminectomy and fusion, with or without instrumentation.

CONCLUSIONS

Decompression primarily relieves radicular symptoms and neurogenic claudication whereas fusion primarily relieves back pain by elimination of instability. The goals for instrumentation are to promote fusion and to correct deformity. Fusion has a better long-term outcome than decompression alone. There is evidence that instrumentation improves fusion rate but does not improve clinical outcome in a relatively short-term follow-up. However, outcome of pseudarthrosis cases deteriorates over time and solid fusion produces better long-term outcome. The benefit of instrumentation comes with a price of higher postoperative morbidity and complication rate. Bone morphogenetic proteins are being tried to increase the rate of fusion, without increasing the complication rate, but the cost is prohibitive. More recently, dynamic stabilization with instrumentation but without fusion has been introduced as an alternative treatment. The current trends of surgical treatment and controversies are discussed.

Contemporary transsphenoidal surgery for pituitary adenomas with emphasis on complications

The indication and complications of transsphenoidal surgery (TSS) were reported with an emphasis on our experiences. Although new therapies have been developed one after another, TSS is still main stream in the treatment of most pituitary adenomas. One century after the birth of TSS, it has evolved into a more sophisticated and less invasive procedure. The present microscopic TSS will be replaced by endoscopic TSS in the near future. Complications can occur with any surgery, but we can reduce their possibility and degree by enriching experience. In our series, the morbidity rate was 2.7%, but operative death was absent. A better understanding of the reported complications and a careful preoperative design will contribute to a better outcome of TSS.

The treatment of a thyrotropin-secreting pituitary macroadenoma with octreotide in twin pregnancy

TSH-secreting pituitary tumours are rare but difficult to treat due to a combination of refractory hyperthyroidism and low surgical cure rates. We describe the case of a 21-year-old woman who, despite twin pregnancy, became euthyroid and had dramatic tumour shrinkage on octreotide treatment. To our knowledge, this is the first description of the use of octreotide for a TSH-secreting pituitary adenoma throughout pregnancy.

[TSH pituitary adenoma: case report]

We describe a rare case of thyroid-stimulating hormone-secreting pituitary adenoma in a patient with a clinical picture of hyperthyroidism, that developed bitemporal hemianopsia after four years of a known thyroid dysfunction. CT scan showed a pituitary tumor considered grade 2 and stage C according to Hardy-Vezina and Wilson. Treatment was surgical, initially by a transsphenoidal approach, in which only a biopsy was possible. The patient was then submitted to an orbital-pterional craniotomy with sub-total resection of the tumor. Complementary treatment was indicated with radiotherapy.

Classification of pituitary adenomas

This brief review summarizes various schemes which were introduced to classify pituitary tumors of adenohypophysial origin. Many different classifications were proposed. Pathologists prefer classifications based on the morphologic features of tumor cells. The gold standard is the light microscopic study of hematoxylin-eosin stained sections of formalin fixed and paraffin-embedded tissues. For correlation between hormone production, secretory activity and cytogenesis, immunohistochemical and transmission electron microscopic investigation is needed. We are convinced that in the future, molecular and genetic techniques will also be applied. We present here our five-tier scheme for classification of pituitary tumors which was accepted by the 'World Health Organization International Histological Classification of Tumours'. This classification takes into consideration the clinical and laboratory findings, imaging results, histologic, immunocytochemical and ultrastructural features of tumor cells. Despite several recent attempts to assess the growth rate, aggressiveness and invasiveness of pituitary tumors, more work is required to draw conclusions on their prognosis.

Coexistence of thyrotropin-producing pituitary adenoma with papillary adenocarcinoma of the thyroid--a case report and surgical strategy

We report a very rare case of thyrotropin (thyroxin stimulating hormone, TSH)-producing pituitary adenoma coexisting with a papillary adenocarcinoma of the thyroid. A 45-year-old woman presented with hyperhidrosis and a nodule in the left thyroid that was first noticed one year earlier. An endocrinological examination showed elevated serum levels of free triiodothyronine (T3) and free throxin (T4) without inhibition of TSH, suggesting the presence of syndromes of inappropriate secretion of TSH. A specimen obtained by needle aspiration of the thyroid nodule revealed the presence of papillary adenocarcinoma. Magnetic resonance images demonstrated a pituitary macroadenoma. The patient was diagnosed as having a TSH-producing pituitary adenoma coexisting with a papillary adenocarcinoma of the thyroid. The patient underwent a total thyroidectomy with resection of the neighboring lymph nodes. Two weeks after this surgery, the pituitary adenoma was totally removed via a pterional approach. Histological and immunohistochemical examinations of the surgical specimens confirmed the lesion as a papillary adenocarcinoma of the thyroid and a TSH-producing pituitary adenoma. Serum TSH levels decreased to undetectable levels immediately after the surgery for the pituitary adenoma. Prolonged stimulation of the thyroid gland by TSH may be involved in the growth of thyroid carcinoma. In cases with a TSH-producing pituitary adenoma, the possible coexistence of thyroid carcinoma should be carefully ruled out. In such cases, a total thyroidectomy followed by TSH level normalization should be performed. Incomplete removal of the thyroid might enable the carcinoma to re-grow if TSH level can not be normalized after the pituitary adenomectomy.

S, Leite V, Canadas V. Tratamento medicamentoso dos tumores hipofisários. parte II: adenomas secretores de ACTH, TSH e adenomas clinicamente não-funcionantes

Este artigo revisa o potencial papel do tratamento medicamentoso para os adenomas hipofisários secretores de ACTH, TSH e aqueles clinicamente não-funcionantes (ACNF), Metirapona, mitotano e cetoconazol (preferível por causar menos efeitos colaterais) são as drogas mais eficazes no controle do hipercortisolismo, mas nenhuma delas supera a eficácia da cirurgia transesfenoidal (TSA). O tratamento medicamentoso da doença de Cushing está, portanto, melhor indicado para pacientes aguardando o efeito pleno da radioterapia ou, como alternativa para esta última, em casos de hipercortisolismo persistente após TSA, e para pacientes com rejeição ou limitações clínicas para a cirurgia. Outra indicação potencial seria em idosos com microadenomas ou pequenos macroadenomas, ou em casos associados a sela vazia. No que se refere aos adenomas secretores de TSH, os análogos somatostatínicos (SRIFa) proporcionam normalização dos hormônios tiroideanos em até 95% dos casos. Assim, eles podem se mostrar úteis em casos de insucesso da cirurgia ou como terapia primária de casos selecionados. Ocasionalmente, agonistas dopaminérgicos (DA), sobretudo a cabergolina, também podem ser eficazes. Em contraste, DA e SRIFa raramente induzem uma significante redução das dimensões dos ACNFs. Por isso, em pacientes com tais tumores, essas drogas devem ser principalmente consideradas diante de contra-indicações ou limitações clínicas para a cirurgia ou quando a cirurgia e a radioterapia tenham sido mal-sucedidas.