An aberrant ACTH-producing ectopic pituitary adenoma in the sphenoid sinus

Subclinical Cushing's Disease with High-Molecular-Weight Forms of Adrenocorticotropic Hormone Production

Production of the high-molecular-weight forms of adrenocorticotropic hormone (big-ACTH) has been reported in a small number of ectopic ACTH syndrome and ACTH-producing pituitary macroadenoma. However, perioperative changes in big-ACTH in patients with subclinical Cushing's disease have not been reported. A 63-year-old woman presented 25 × 20 × 20-mm-sized macroadenoma in the pituitary gland. Her early morning plasma ACTH and cortisol levels were 111 pg/mL and 11.6 μg/dL, respectively. Cushingoid features and diurnal variation in plasma cortisol levels were not observed. The patient's urinary free cortisol (UFC) was 59.3 μg/day. The corticotropin-releasing hormone (CRH) test showed that plasma ACTH levels were 1.5 times higher than the preload value. The overnight dexamethasone suppression test (DST) showed that the plasma cortisol level was not suppressed by 0.5 mg of dexamethasone (DEX) but was suppressed by 8 mg of DEX. Inferior pyramidal sinus sampling was consistent with Cushing's disease. Taken together, the patient was clinically diagnosed with subclinical Cushing's disease caused by an ACTH-producing pituitary adenoma. Endoscopic transsphenoidal adenomectomy was performed. In the postoperative CRH test, plasma ACTH levels showed six-fold increase. The postoperative DST showed cortisol suppression at 0.5 mg of DEX. The UFC levels decreased to 35.1 μg/day. Pituitary contrast-enhanced MRI revealed no residual tumor, and plasma ACTH and cortisol levels remained within normal ranges. Gel filtration of preoperative and postoperative plasma ACTH was performed, and a high molecular weight fraction of ACTH was detected, which markedly decreased postoperatively. The absence of Cushingoid features and the lack of significant cortisol hypersecretion in this case were thought to be due in part to big-ACTH, which has low bioactivity. By careful evaluation of laboratory and clinical findings, we identified it as a big-ACTH-producing adenoma. This is the first report of a case in which the big-ACTH transition was observed perioperative and is a valuable case.

Clinical and radiological presentation of parasellar ectopic pituitary adenomas: case series and systematic review of the literature

PURPOSE

Parasellar ectopic pituitary adenomas (pEPAs) are extremely rare tumors located out of the sella turcica. PEPAs are heterogeneous entities in terms of anatomical localization and secretion of anterior pituitary hormones.

METHODS

Multicenter retrospective study. Clinical charts' consultation of patients diagnosed with parasellar lesions, to identify all subjects fulfilling the diagnostic criteria of parasellar EPAs. Systematic review of the literature focused on the medical management of prolactin-secreting pEPAs and on the prevalence of radiological bone invasion in pEPAs.

RESULTS

We identified four cases of pEPAs: (1) 54-year-old female with a prolactin-secreting suprasellar EPA successfully treated with cabergoline; (2) 74-year-old male with a non-functioning EPA of the sphenoidal sinus treated with endoscopic transsphenoidal surgery; (3) 75-year-old female with a giant lesion of the skull base (maximum diameter 7.2 cm) diagnosed as a non-functioning EPA after biopsy; (4) 49-year-old male with a silent corticotroph EPA of the sphenoidal sinus and clivus. Three out of four cases had radiological evidence of invasion of the surrounding bone structures. A systematic review of the literature highlighted that medical therapy can be effective in prolactin-secreting pEPAs. Overall, we found mention of local invasiveness in 65/147 cases (44.2%), confirmed by radiological signs of bone invasion/erosion.

CONCLUSION

Our experience confirms the heterogeneity of pEPAs in terms of clinical and radiological presentation, as well as hormone secretion. PEPAs show a high frequency of radiological bone invasion, though similar to that of sellar pituitary adenomas. Although extremely rare, pEPAs need to be considered in the differential diagnosis of parasellar lesions.

Ectopic pituitary adenomas: clinical features, diagnostic challenges and management

PURPOSE

Ectopic pituitary adenomas (EPAs) are extremely rare pituitary adenomas located outside the sella turcica without any connection with intrasellar components. This study aims to review all the reported cases to date and describe the clinical characteristics of EPAs.

METHODS

In a retrospective chart review, 14 patients were identified with EPAs in our hospital. A literature review was performed, and 166 cases in the literature met the criteria. Clinical data were analyzed.

RESULTS

Of 180 patients with EPAs, the mean age at diagnosis was 45.4 years, and 66.5% of the patients were females. EPAs were mainly located in the sphenoid sinus (34.4%) and suprasellar region (25.6%), followed by the clivus (15.6%), cavernous sinus (13.3%) and nasopharynx (5.6%). Adrenocorticotropic hormone (ACTH)-secreting (38.9%) and nonfunctioning (27.2%) adenomas were predominant. Patients with suprasellar EPAs were more likely to present menstrual disorders and visual changes, while patients with clival EPAs were more likely to suffer from headaches. EPAs in the cavernous sinus and suprasellar space were more likely to be initially misdiagnosed as a suspicious intrasellar mass on imaging examination. The complete tumor resection rates for EPAs in the sphenoid sinus, suprasellar region, clivus, cavernous sinus and nasopharynx were 72.3%, 88.6%, 45.0%, 73.3% and 88.9%, respectively.

CONCLUSIONS

EPA clinical characteristics varied across different tumor locations and hormone-secreting types. In addition to comprehensive hormone evaluation and careful review of imaging data, nuclear medicine and surgical biopsy should also be considered when facing differential difficulty. EPA management should be individualized.

Long-term follow-up for ectopic ACTH-secreting pituitary adenoma in a single tertiary medical center and a literature review

BACKGROUND

Ectopic ACTH-secreting pituitary adenoma (EAPA) are a rare cause of Cushing's disease. Due to the lack of consensus and experience in terms of the diagnosis and treatment of EAPAs, preoperative identification and optimal treatment remain challenging.

PURPOSE

To investigate the characteristics of EAPAs and offer some proposals for the diagnosis and management of this uncommon disease, the EAPA patients admitted to our center and all of the EAPA cases reported in the literature were reviewed.

METHODS

In a retrospective electronic medical chart review, 6 patients (0.39%) with EAPAs were identified from 1536 consecutive patients who were admitted to our hospital with a diagnosis of Cushing's syndrome between January 2000 and August 2019. A literature review was performed on the online databases PubMed and EMBASE, and 52 cases conformed to the criteria. The data regarding biochemical tests, imaging examinations and follow-ups were analyzed.

RESULTS

The mean age of patients with EAPAs was 37.7 years old, and an obvious female predominance (3.5: 1) was demonstrated. The most common location of EAPAs was the cavernous sinus (34.5%), followed by the sphenoid sinus (31.0%) and the suprasellar region (20.7%). No significant differences in the biochemical test results were found among tumors in different locations. Except for sex, no risk factors related to remission were found. Although no significant differences among different locations were found, the tumors in the cavernous sinus had a relatively higher rate of invisibility in terms of imaging and a higher non-remission rate than tumors in other locations.

CONCLUSIONS

In patients with negative intrasellar findings, the uncommon disease of EAPA should be considered. Due to the endocrine similarity between intrasellar pituitary corticotrophin adenoma and EAPA, the preoperative identification of EAPA depends on a careful review of the imaging examinations. Locations such as the cavernous sinus, sphenoid sinus and suprasellar region should be considered first. Tumor resection is recommended when the diagnosis is confirmed.

Presence of aberrant adrenocorticotropic hormone precursors in two cases of McCune-Albright syndrome

McCune-Albright syndrome (MAS) is a rare disorder. MAS is classically defined by the occurrence of fibrous dysplasia, café-au-lait skin macules, and precocious puberty. In addition to precocious puberty, other hyperfunctioning endocrinopathies may occur. We evaluated hypothalamic-pituitary-adrenal function in two cases of typical MAS associated with fibrous dysplasia and growth hormone excess. Pituitary adenoma or hyperplasia was not detected by magnetic resonance imaging. Hormonal data showed normal or low cortisol levels, despite high ACTH levels in the blood. A high ratio of circulating ACTH to cortisol was found in the two cases. Insulin tolerance and CRH tests showed hyper-responses of ACTH and an insufficient increase in cortisol levels. No involvement of 11β-HSD1 by GH excess was suggested because basal levels of ACTH and cortisol showed no changes, even after therapy for acromegaly by somatostatin analogues. Patients with Cushing's disease cases of pituitary macroadenoma can have high circulating ACTH precursor levels, and elevated ACTH precursors have been observed in ectopic ACTH syndrome. Autonomous cortisol excess was excluded by the level of midnight cortisol and the level of cortisol after a low-dose dexamethasone suppression test in the two cases. Finally, the gel filtration profiles of immunoreactive ACTH contents showed the presence of aberrant ACTH precursors. To the best of our knowledge, there have been no reports of MAS associated with aberrant ACTH precursors. Our findings in these cases emphasize that attention should be to secretion of inactive ACTH precursors in MAS.

Ectopic Cushing's syndrome in a patient with inferior petrosal sinus sampling indicating pituitary-dependent ACTH secretion

In an unclear case of Cushing's syndrome, IPSS identifies the origin of ACTH secretion, and together with MRI enables the localization of an ectopic corticotroph adenoma in the parasellar or cavernous sinuses region.

Pituitary Adenoma Deposit in the Nasolabial Region Following Sublabial Transsphenoidal Surgery in the Setting of Nelson Syndrome

Pituitary adenomas are a group of tumors arising from the anterior pituitary gland, and with the exception of prolactin-secreting adenomas, transsphenoidal resection is the cornerstone of treatment. Although most adenomas are located within the pituitary fossa, ectopic adenomas have been reported, primarily occurring along the route of embryologic development. In this article, we present the case of an ectopic pituitary adenoma in the nasolabial fold that likely resulted from seeding during transsphenoidal resection via sublabial approach.

Variability in Clinical Presentation and Pathologic Implications of Ectopic Pituitary Tumors: Critical Review of Literature

OBJECTIVE

Pituitary tumors are common, well-described skull base tumors of sellar origin. However, there are reports of rare ectopic pituitary tumors that are found exclusively outside of the sella turcica. Ectopic pituitary tumors have not been holistically analyzed. This study describes presentation and clinical patterns found among patients with ectopic pituitary tumors.

METHODS

A comprehensive review of the literature was performed for clinical descriptions of ectopic pituitary tumors. Reports of 85 applicable cases were evaluated.

RESULTS

The most common locations of ectopic pituitary tumors were the sphenoid sinus, clivus, suprasellar space, nasopharynx, and cavernous sinus. The majority of ectopic pituitary tumors were reported as being functional secretory tumors; they were statistically significantly more likely to be functional tumors than sellar pituitary tumors. Adrenocorticotrophic hormone, prolactin, growth hormone, and thyroid-stimulating hormone-secreting tumors were most commonly found. Bone invasion was reported in more than one third of the cases, and malignant transformations were reported in 6 cases. A large majority of patients presented with hormonal, neurologic, or physiologic symptoms.

CONCLUSIONS

Ectopic pituitary tumors are a rare entity of pituitary tumors with a presentation that can mimic those of other skull base tumors. Clinical presentation often correlates to location of the tumor. Ectopic pituitary tumors were significantly more likely to be functional secretory tumors. They may also exhibit more aggressive behavior than sellar-located tumors. Ectopic pituitary tumors may be part of a spectrum of presenting pathologies. Further genetic or genomic analysis is necessary to better understand their pathogenesis and clinical presentations.

[Ectopia of the pituitary]

The adenohypophysis has a large intrasellar part and two small parts at the pituitary stalk and the pharynx. Near this extrasellar pituitary tissue, and also in sinus sphenoidalis and sinus cavernosus, ectopic pituitary adenomas can develop. They are indistinguishable in structure and function from usual intrasellar adenomas. The neurohypophysis can show dystopias within complex malformations. In so-called pituitary stalk interruption syndrome, a real ectopia of the neurohypophysis is found at the eminentia mediana of the hypothalamus. Ectopic tissue in the pituitary is extremely rare: foci of ganglionic cells were found in the neurohypophysis and adrenocortical tissue in the adenohypophysis. Focal squamous epithelia in the anterior pituitary are a common finding but they are rather metaplastic from parenchymal cells than ectopic tissue. Small foci of ectopic salivary gland tissue are not rare in the intermediate zone.

Clinical and Anatomic Features of Supraglandular Pituitary Adenomas

OBJECTIVE

Supraglandular pituitary adenoma (SGPA) is one of the extraordinary pituitary adenomas and shows different clinical and radiologic features. We retrospectively reviewed our cases of SGPAs to elucidate the radiologic, anatomic, and clinical features.

METHODS

We identified 9 patients with pathologically proven SGPA and classified them into 2 groups radiologically: either glandular or stalk types. Magnetic resonance images were correlated with intraoperative anatomic differences between the groups. Clinical and endocrinologic characteristics and surgical outcomes were reviewed.

RESULTS

The proportion of SGPAs was 1.2% of all pituitary adenomas surgically treated in our patient cohort. The glandular-type tumors (n = 7) had a thinned or defective diaphragma sellae. There was a clear plane between the tumor and pituitary stalk. For the stalk-type tumors (n = 2), the diaphragma sellae was intact and no clear border between the mass and stalk was found. Endocrinologic and immunohistochemical evaluation showed that 5 of 7 glandular-type tumors (71%) were functioning pituitary adenomas, whereas 2 stalk-type tumors were nonfunctioning. Eight of 9 patients underwent an endoscopic endonasal approach and tumor was totally removed in 7 (78%).

CONCLUSIONS

SGPAs are rare and preoperative diagnosis is possible based on their distinct radiologic, clinical, and anatomic features. SGPAs can be divided into 2 groups according to the anatomic features. The origin of tumor, whether the superior surface of the gland or the pituitary stalk, determined the location, extent, and relationship with the diaphragma sellae. The surgical outcome via an endoscopic endonasal approach was favorable.

Concomitant Cushing's Disease and Marked Hyperprolactinemia: Response to a Dopamine Receptor Agonist

A 38-year-old woman was admitted to our hospital because of amenorrhea, multiple bone fractures, and a Cushingoid appearance. Endocrinological investigations revealed that she had co-existing Cushing's disease and prolactinoma, with a serum level of prolactin (PRL) at 1,480 ng/mL, corticotropin (ACTH) at 81.3 pg/mL, and cortisol at 16.6 μg/dL. Due to the lack of indication for transsphenoidal surgery, cabergoline monotherapy was initiated. A 6-month course of treatment resulted in only subtle amelioration of hypercortisolism, while hyperprolactinemia was dramatically improved. In 5 cases of bihormonal (ACTH/PRL) pituitary macroadenoma reported in the English literature, 2 were initially treated with dopaminergic agonists with substantial effectiveness for both PRL and ACTH. We herein report an extremely rare case of bihormonal macroadenoma in which only PRL was responsive to treatment.

Ectopic ACTH-secreting pituitary adenoma of the sphenoid sinus: case report of endoscopic endonasal resection and systematic review of the literature

Ectopic pituitary adenomas are exceedingly rare entities that are often misdiagnosed. The resulting delay in diagnosis may be particularly concerning in the case of Cushing syndrome caused by an ectopic adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma. Although the total resection of ectopic adenomas results in rapid and durable remission, persistent Cushing syndrome is often associated with permanently damaging invasive procedures and significantly higher risk of mortality. The authors report the case of a 48-year-old man with ACTH-dependent Cushing syndrome. On the morning before surgery, his serum cortisol measured 51 μg/dl, his ACTH level was 195.7 pg/ml, and his urinary free cortisol level was 2109 μg/day. Serum cortisol was not suppressed with the administration of high-dose dexamethasone. Imaging showed separate masses in both the sphenoid sinus and the pituitary gland, complicating the diagnostic process and requiring pathological assessment of both masses. No other abnormalities were found on thoracic, abdominal, or pelvic scans. Gross-total resection of both lesions was accomplished via an endoscopic endonasal transsphenoidal approach. Pathology confirmed an ectopic ACTH pituitary adenoma of the sphenoid sinus and a Crooke hyaline change of the pituitary gland. The patient achieved stable hormonal remission without significant postoperative complications, returned to full activity within 3 months, and remained disease free nearly 1 year after tumor resection. In a systematic literature review, the authors identified 41 cases of ectopic ACTH-secreting pituitary adenomas, including 18 arising in the sphenoid sinus without direct involvement of the sella. Including the case described here, the total number of ectopic ACTH pituitary adenomas arising in the sphenoid sinus was 19, and the total number of ectopic ACTH pituitary adenomas without regard to location was 42. For the 19 patients with adenomas found in the sphenoid sinus, ages ranged from 16 to 76 years, and there were 15 women and 4 men. The mean and median diameters of the resected sphenoid masses were 13.9 and 8 mm, respectively, with a range of 3-55 mm. Seven were microadenomas (< 1 cm). Fifteen of the 19 cases reported serum ACTH and morning cortisol levels, the means of which were 106.7 pg/ml and 32.5 μg/dl, respectively. Gross-total tumor resection was achieved in all patients except one, and in all of them durable hormonal remission of Cushing syndrome was achieved (mean follow-up time 20 months). Ectopic pituitary adenomas are rare but important causes of Cushing syndrome and related endocrinopathies, particularly because of the rapid onset and severity of symptoms with atypical presentation. Ectopic pituitary adenomas, especially those in the nasal cavity, nasopharynx, or paranasal sinuses, are easily misidentified. Any patient presenting with signs and symptoms of Cushing syndrome without any obvious pituitary adenoma or other sources of hypercortisolemia should be thoroughly screened for an ectopic adenoma. However, as with the case presented here, the coincident existence of a sellar mass should not preclude the possibility of an ectopic source. There should be a high degree of clinical suspicion for any mass in the general area surrounding the sella when evaluating Cushing syndrome.

A pitfall in diagnosing Cushing's disease: ectopic ACTH-producing pituitary adenoma in the sphenoid sinus

PURPOSE

To show a rare case of Cushing's disease and possible cause of failed transsphenoidal surgery.

METHOD

We report on a 50-year-old woman suffering from ACTH-dependent Cushing's syndrome. Endocrinological work-up including low-dose/high-dose dexamethasone test (Liddle-test) and CRH test were clearly compatible with pituitary origin. Although an MRI showed no pituitary tumor, CRH-stimulated petrosal sinus sampling revealed a significant central-peripheral gradient in ACTH concentrations, rendering Cushing's disease very likely. The patient underwent transsphenoidal surgery with negative exploration of the pituitary gland. After intraoperative re-evaluation of the preoperative MRI, a "polyp" at the bottom of the sphenoid sinus was identified. The intraoperative microscopic aspect as well as instantaneous sections and cytology of a biopsy confirmed an adenoma, which was then removed. Histological analysis demonstrated an ACTH-producing pituitary adenoma adjacent to respiratory mucous membrane consisting of ciliated epithelium with submucous connective tissue. Postoperatively, ACTH concentrations were decreased and intermittent hydrocortisone substitution treatment was initiated. At the 3-month follow up, Cushing's stigmata were found to be alleviated and the hydrocortisone dosage could be reduced.

CONCLUSION

Ectopic pituitary adenoma tissue causing Cushing's disease is extremely rare but a potential cause for surgical failure or re-evaluation.

Paraneoplastic syndromes in olfactory neuroblastoma

Olfactory neuroblastoma (ONB) is a rare malignant neoplasm of sinonasal tract, derived from olfactory epithelium. Unilateral nasal obstruction, epistaxis, sinusitis, and headaches are common symptoms. Olfactory neuroblastoma shows neuroendocrine differentiation and similarly to other neuroendocrine tumors can produce several types of peptic substances and hormones. Excess production of these substances can be responsible for different types of endocrinological paraneoplastic syndromes (PNS). Moreover, besides endocrinological, in ONB may also occur neurological PNS, caused by immune cross-reactivity between tumor and normal host tissues in the nervous system. Paraneoplastic syndromes in ONB include: syndrome of inappropriate ADH secretion (SIADH), ectopic ACTH syndrome (EAS), humoral hypercalcemia of malignancy (HHM), hypertension due to catecholamine secretion by tumor, opsoclonus-myoclonus-ataxia (OMA) and paraneoplastic cerebellar degeneration. Paraneoplastic syndromes in ONB tend to have atypical features, therefore diagnosis may be difficult. In this review, we described initial symptoms, patterns of presentation, treatment and outcome of paraneoplastic syndromes in ONB, reported in the literature.

Ectopic ACTH-secreting pituitary adenomas within the sphenoid sinus

Ectopic pituitary adenomas are defined by the presence of adenomatous pituitary tissue outside the sella and distinctly separate from the pituitary gland. Ectopic ACTH-secreting pituitary adenomas (EAPAs) are a rare cause of Cushing's syndrome. Detecting these radiologically can prove difficult, in part, due to their typically small size and unpredictable anatomical location. In ACTH-dependent Cushing's syndrome, if, despite comprehensive testing, the source of excess ACTH remains occult (including negative work up for ectopic ACTH syndrome) thought should be given to the possibility of the patient harboring an EAPA. In most cases, ectopic ACTH pituitary adenomas within the sphenoid sinus will manifest with symptoms of hormonal excess, have an obvious sphenoid sinus mass on pre-operative imaging and will demonstrate resolution of hypercortisolism after surgical excision if located and removed. Twenty cases of EAPAs have been reported in the literature to date. This paper will review the current literature on all previously reported EAPAs within the sphenoid sinus in addition to the current case.

Nasally located ectopic ACTH-secreting pituitary adenoma (EAPA) causing Nelson's syndrome: diagnostic challenges

PURPOSE

We report the first case of an Ectopic adrenocorticotrophin (ACTH)-secreting pituitary adenoma (EAPA) located within the posterior nasal septum associated with Nelson's syndrome, which eluded diagnosis for over a decade. In this report, we explore the reasons for such diagnostic difficulty and suggest ways in which an earlier diagnosis may be made.

METHODS AND RESULTS

A 19 years old Lebanese man presented in 2000, with overt Cushing's syndrome confirmed with markedly elevated urine free cortisols and failed dexamethasone suppression tests. An unsuppressed ACTH and a possible 5 mm adenoma on MRI (Magnetic Resonance Imaging) pituitary suggested Cushing's disease. The patient underwent trans-sphenoidal surgery (TSS), but histology revealed normal pituitary tissue and Cushing's syndrome persisted. A repeat MRI pituitary showed no anomaly, and extensive investigations failed to locate an ectopic lesion. Subsequently a bilateral adrenalectomy was performed. Over the ensuing years, the patient developed Nelson's syndrome with hyperpigmentation and markedly elevated ACTH levels. Repeated high dose dexamethasone suppression tests, corticotrophin releasing hormone (CRH) tests, and CRH stimulated inferior petrosal sinus samplings (IPSS) suggested a pituitary origin of the ACTH. Two further TSS were unsuccessful. The pituitary was irradiated. Subsequent review of his previous MRIs revealed an enlarging mass within the posterior nasal septum, which was excised in 2011. The histology confirmed the diagnosis of an EAPA within the nasal septum.

CONCLUSION

Ectopic ACTH-secreting pituitary adenomas can occur not only along the developmental route of Rathke's pouch, but other aberrant locations giving a clinical and biochemical picture identical to Cushing's disease or Nelson's syndrome. Clinicians should suspect an EAPA, when a central ACTH source seems to be apparent with no obvious pituitary adenoma. A detailed MRI involving possible EAPA sites aids in locating these unusual lesions.

Hypercortisolaemia due to ectopic adrenocorticotropic hormone secretion by a nasal paraganglioma: a case report and review of the literature

BACKGROUND

Adrenocorticotropic hormone-producing extraadrenal paragangliomas are extremely rare. We present a case of severe hypercortisolemia due to ectopic adrenocorticotropic hormone secretion by a nasal paraganglioma.

CASE PRESENTATION

A 70-year-old Caucasian woman, was emergently admitted to our department with supraventricular tachycardia, oedema of face and extremities and hypertensive crisis. Initial laboratory evaluation revealed severe hypokalemia and hyperglycemia without ketoacidosis, although no diabetes mellitus was previously known. Computed tomography revealed a large tumor obliterating the left paranasal sinus and a left-sided adrenal mass. After cardiovascular stabilisation, a thorough hormonal assessment was performed revealing marked adrenocorticotropic hormone-dependent hypercortisolism. Due to the presence of a cardiac pacemaker magnetic resonance imaging of the hypophysis was not possible. [68Ga-DOTA]-TATE-Positron-Emission-Tomography was performed, showing somatostatin-receptor expression of the paranasal lesion but not of the adrenal lesion or the hypophysis. The paranasal tumor was resected and found to be an adrenocorticotropic hormone-producing paraganglioma of low-proliferative rate. Postoperatively the patient became normokaliaemic, normoglycemic and normotensive without further need for medication. Genetic testing showed no mutation of the succinatdehydrogenase subunit B- and D genes, thus excluding hereditary paragangliosis.

CONCLUSION

Detection of the adrenocorticotropic hormone source in Cushing's syndrome can prove extremely challenging, especially when commonly used imaging modalities are unavailable or inconclusive. The present case was further complicated by the simultaneous detection of two tumorous lesions of initially unclear biochemical behaviour. In such cases, novel diagnostic tools - such as somatostatin-receptor imaging - can prove useful in localising hormonally active neuroendocrine tissue. The clinical aspects of the case are discussed and relevant literature is reviewed.

Detection of paranasal ectopic adrenocorticotropic hormone-secreting pituitary adenoma by Ga-68-DOTANOC positron-emission tomography-computed tomography

Ectopic adrenocorticotropic hormone (ACTH)-secreting tumors account for approximately 10% of Cushing's syndrome (CS). We present an extremely rare case of a patient with CS caused by an ectopic ACTH-secreting pituitary adenoma (EAPA) of the ethmoid sinus. The tumor was identified by positron-emission tomography-computed tomography (PET/CT) using the somatostatin receptor analogue Ga-68-DOTANOC. Transnasal endoscopic resection was performed and the patient showed significant clinical improvement with normalization of the endocrine pituitary axis. Immunostaining showed a somatostatin receptor 2 and 5-positive ACTH-producing adenoma. In patients with ectopic ACTH secretion, Ga-68-DOTANOC-PET/CT may play an important role in the localization of EAPA. Transnasal endoscopic resection is the therapy of choice.

Ectopic sphenoid sinus pituitary adenoma (ESSPA) with normal anterior pituitary gland: a clinicopathologic and immunophenotypic study of 32 cases with a comprehensive review of the english literature

Ectopic sphenoid sinus pituitary adenoma (ESSPA) may arise from a remnant of Rathke's pouch. These tumors are frequently misdiagnosed as other neuroendocrine or epithelial neoplasms which may develop in this site (olfactory neuroblastoma, neuroendocrine carcinoma, sinonasal undifferentiated carcinoma, paraganglioma, melanoma). Thirty-two patients with ESSPA identified in patients with normal pituitary glands (intact sella turcica) were retrospectively retrieved from the consultation files of the authors' institutions. Clinical records were reviewed with follow-up obtained. An immunohistochemical panel was performed on available material. Sixteen males and 16 females, aged 2-84 years (mean, 57.1 years), presented with chronic sinusitis, headache, obstructive symptoms, and visual field defects, although several were asymptomatic (n = 6). By definition, the tumors were centered within the sphenoid sinus and demonstrated, by imaging studies or intraoperative examination, a normal sella turcica without a concurrent pituitary adenoma. A subset of tumors showed extension into the nasal cavity (n = 5) or nasopharynx (n = 9). Mean tumor size was 3.4 cm. The majority of tumors were beneath an intact respiratory epithelium (n = 22), arranged in many different patterns (solid, packets, organoid, pseudorosette-rosette, pseudopapillary, single file, glandular, trabecular, insular). Bone involvement was frequently seen (n = 21). Secretions were present (n = 16). Necrosis was noted in 8 tumors. The tumors showed a variable cellularity, with polygonal, plasmacytoid, granular, and oncocytic tumor cells. Severe pleomorphism was uncommon (n = 5). A delicate, salt-and-pepper chromatin distribution was seen. In addition, there were intranuclear cytoplasmic inclusions (n = 25) and multinucleated tumor cells (n = 18). Mitotic figures were infrequent, with a mean of 1 per 10 HPFs and a <1% proliferation index (Ki-67). There was a vascularized to sclerotic or calcified stroma. Immunohistochemistry highlighted the endocrine nature of the tumors, with synaptophysin (97%), CD56 (91%), NSE (76%) and chromogranin (71%); while pan-cytokeratin was positive in 79%, frequently with a dot-like Golgi accentuation (50%). Reactivity with pituitary hormones included 48% reactive for 2 or more hormones (plurihormonal), and 33% reactive for a single hormone, with prolactin seen most frequently (59%); 19% of cases were non-reactive. The principle differential diagnosis includes olfactory neuroblastoma, neuroendocrine carcinoma, melanoma, and meningioma. All patients were treated with surgery. No patients died from disease, although one patient died with persistent disease (0.8 months). Surgery is curative in the majority of cases, although recurrence/persistence was seen in 4 patients (13.8%). In conclusion, ESSPAs are rare, affecting middle aged patients with non-specific symptoms, showing characteristic light microscopy and immunohistochemical features of their intrasellar counterparts. When encountering a tumor within the sphenoid sinus, ectopic pituitary adenoma must be considered, and pertinent imaging, clinical, and immunohistochemical evaluation undertaken to exclude tumors within the differential diagnosis. This will result in accurate classification, helping to prevent the potentially untoward side effects or complications of incorrect therapy.

Kaposi sarcoma related to an ectopic hypothalamic adrenocorticotropic hormone-secreting adenoma: case report

OBJECTIVE

We aim to report a case of Kaposi sarcoma (KS) with Cushing's syndrome caused by endogenic glucocorticoid-induced immunosuppression.

CLINICAL PRESENTATION

A 43-year-old woman presented with delirium, hirsutism, fatigue, and hypertension. At the time of presentation, physical findings showed a Cushingoid appearance, with moon-like facies, hirsutism, and hyperpigmentation. Laboratory findings showed the following: adrenocorticotropic hormone, 86.7 pg/mL (normal range, 0-46 pg/mL); baseline cortisol level, 50 microg/dL (normal range, 6.2-19 microg/dL); potassium, 2.2 mEq/L (normal range, 3.5-5 mEq/L); and midnight cortisol level, 33 microg/dL. Serum cortisol levels failed to suppress after low and high doses of dexamethasone; these findings confirmed the diagnosis of ectopic adrenocorticotropic hormone production. Magnetic resonance imaging revealed a 12 x 15-mm, round, hypothalamic mass lesion in the center of the median eminence.

INTERVENTION

Endoscopic biopsy from the floor of the third ventricle was performed, and pathological examination of the lesion showed a diffuse adrenocorticotropic hormone-secreting adenoma. The patient developed diffuse skin lesions that were proven to be a KS by skin biopsy while she was prepared for transcranial surgery. After surgical removal of the adenoma, she became hypocortisolemic and required cortisol replacement. Within 1 month after surgery, all KS lesions disappeared spontaneously.

CONCLUSION

Excessive cortisol may induce immunosuppression. KS is one of the most common malignant tumors of patients with immunosuppression. To the best of our knowledge, this is the first case of Cushing's syndrome with KS caused by endogenous glucocorticoid-induced immunosuppression.

Location of ectopic adrenocortical hormone-secreting tumors causing Cushing's syndrome in the paranasal sinuses

BACKGROUND

The majority of ectopic adrenocorticotropic hormone (ACTH)-secreting tumors are localized in the chest or abdomen. Occasionally, these tumors are found in the paranasal sinuses.

METHODS

We present 2 unusual cases of ectopic ACTH syndrome whose ACTH-secreting tumors were localized in the paranasal sinuses and describe their biochemical and radiological presentation.

RESULTS

The first patient had an ACTH-secreting olphactory neuroblastoma originating in the ethmoid sinuses. The second patient had a clinical course and biochemical findings indistinguishable from pituitary ACTH-dependent Cushing's syndrome, except for negative petrosal sinus sampling. Head imaging showed a "polyp" in the left maxillary sinus-secreting ACTH. Both patients went into remission following surgical resection and recovered normal pituitary-adrenal axis function.

CONCLUSION

Ectopic ACTH secretion may originate from lesions in the paranasal sinuses. This accessible location allows for direct immunohistochemical diagnosis with ACTH staining. Surgical resection/radiation therapy can result in complete remission of the disease and restoration of normal pituitary-adrenal function.

Sphenoid sinus ectopic pituitary adenomas: CT and MRI findings

Ectopic pituitary adenomas (EPAs) are rare lesions. The purpose of this study was to describe the CT and MRI features of sphenoid sinus EPAs. Eight patients with histology-proven EPAs in the sphenoid sinus, all of whom underwent CT and MRI, were reviewed retrospectively. The following imaging features were analysed: (i) size, (ii) margin, (iii) CT attenuation characteristics and (iv) MRI signal intensity. In addition, the involvement of adjacent structures and the time-intensity curve (TIC) of dynamic contrast-enhanced (DCE) MRI were analysed. All EPAs had well-defined margins and showed no relationship to the intrasellar pituitary gland. The mean size was 28 mm (range, 20-46 mm). On non-enhanced CT, the lesions appeared isodense to grey matter in 7 (88%) patients and hypodense in 1 (12%) patient. Only two patients underwent post-contrast CT, and they showed moderate enhancement. On T1 weighted images, EPAs appeared isointense in 6 (75%) patients and hypointense in 2 (25%). On T2 weighted images, the lesions appeared hyperintense in 2 (25%) patients and isointense in 6 (75%). EPAs showed mild to moderate heterogeneous contrast enhancement and exhibited a cribriform-like appearance. Two patients underwent DCE MRI; the TIC showed a rapidly enhancing and slow washout pattern. The following features were also seen: an empty sella, bone changes and involvement of the cavernous sinus (5 patients; 62.5%). In conclusion, a high index of suspicion for EPA and a familiarity with the imaging findings may help to diagnose this rare entity accurately.

Unusual causes of Cushing's syndrome

Although in the majority of the patients with Cushing's syndrome (CS), hypercortisolism is due to ACTH hypersecretion by a pituitary tumour or to ectopic ACTH secretion from an extrapituitary neoplastic lesion or to autonomous cortisol secretion by an adrenal tumour, in occasional patients a much rarer entity may be the cause of the syndrome. Herein, we attempted to summarise and categorise these unusual causes according to their presumed aetiology. To this end, we performed a comprehensive computer-based search for unusual or rare causes of CS. The following unusual forms of CS were identified: (i) ACTH hyperesecretion due to ectopic corticotroph adenomas in the parasellar region or the neurohypophysis, or as part of double adenomas, or gangliocytomas; (ii) ACTH hypersecretion due to ectopic CRH or CRH-like peptide secretion by various neoplasms; (iii) ACTH-independent cortisol hypersecretion from ectopic or bilateral adrenal adenomas; (iv) glucocorticoid hypersensitivity; (v) iatrogenic, due to megestrol administration or to ritonavir and fluticasone co-administration. Such unusual presentations of CS illustrate why Cushing's syndrome represents one of the most puzzling endocrine syndromes.

Reduction of a pancreatic tumor after total removal of an ACTH secreting pituitary tumor: differential diagnosis of Cushing's syndrome

Endocrinologic tests sometimes fail to distinguish adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma from ectopic ACTH-secreting tumor. The authors experienced a case of Cushing's disease associated with a pancreatic tumor. Venous sampling contributed to the final diagnosis of Cushing's disease in this complex case, while endocrinologic tests showed paradoxical results. A 54-year-old woman presented with Cushing's syndrome and pancreatic tumor. Magnetic resonance imaging (MRI) failed to reveal a pituitary tumor, but a gadolinium-enhanced tumor with cystic components was seen in the pancreatic tail. Results of conventional endocrinologic tests suggested ectopic ACTH syndrome, but venous sampling including cavernous sinus sampling indicated an ACTH-secreting pituitary adenoma. Transsphenoidal surgery revealed a pituitary microadenoma, and total removal of the tumor was achieved. Postoperative abdominal MRI revealed that the pancreatic tumor diminished gradually without treatment. Selective cavernous sinus sampling was useful for distinguishing ACTH-secreting pituitary adenoma from ectopic ACTH syndrome in this complex case. This was a rare case in which the pancreatic tumor diminished after total removal of the ACTH-secreting pituitary adenoma.

Periodic secretion of adrenocorticotropin in a patient with Cushing's disease manifested during pregnancy

We report the case of 19-year-old woman with cyclical Cushing's disease, in whom plasma adrenocorticotropin (ACTH) was secreted periodically after her first pregnancy. Since the 33rd week of pregnancy, hypertension and proteinuria became clinically remarkable. She gave normal birth at 36th week of pregnancy; however she continued to gain body weight even after delivery and developed typical Cushingoid features. Her ACTH secretion lacked normal daily fluctuation but exhibited periodic change during 1-year observation, showing 119 pg/ml, 34.6 pg/ml and 115 pg/ml at the 4th, 7th and 13th months after delivery. Plasma ACTH levels were increased by corticotropin releasing hormone and metyrapone, while low-dose dexamethasone suppressed cortisol secretion. Gel filtration analysis of the patient's plasma detected big ACTH molecules being eluted with a peak of authentic 1-39 ACTH. Cranial magnetic resonance imaging revealed a 1-cm pituitary mass in right cavernous sinus. The pituitary tumor was removed by transsphenoidal surgery at 13th month after delivery and was pathologically compatible with ACTH-producing pituitary adenoma by immunohistochemistry. This case includes clinically rare subsets of Cushing's syndrome showing periodic ACTH secretion and aberrant ACTH molecules.