Intra-sellar salivary gland-like pleomorphic adenoma arising within the wall of a Rathke's cleft cyst

Endoscopic Endonasal Surgery for Uncommon Pathologies of the Sellar and Parasellar Regions

Endoscopic skull base surgery has become an integral part of the present neurosurgical armamentarium. The pioneering efforts in which the purely endoscopic transsphenoidal approach was introduced have triggered a growing tide of using the endoscopic endonasal procedures for a large variety of skull base lesions. Because of their anatomical peculiarities, lesions of the sellar and parasellar regions lend themselves very well to the endoscopic endonasal approaches. Apart from the common pathological entities, many other less frequent pathologies are encountered in the sellar and parasellar area. In this chapter, we review the surgical technique of the endoscopic endonasal transsphenoidal approach and its extensions applied to a variety of rare and uncommon pathological entities involving the sella turcica and clivus. An overview of these pathological entities is also presented and exemplified.

Salivary gland tissues and derived primary and metastatic neoplasms: unusual pitfalls in the work-up of sellar lesions. A systematic review

PURPOSE

Salivary gland (SG) tissue and derived neoplasms may occur in the sellar region. As the current literature is mostly limited to case reports, the puzzling case of an inflammatory SG removed by transsphenoidal surgery (TS) and mimicking a prolactinoma prompted us to perform the first systematic review of these unusual conditions.

METHODS

A systematic literature search was conducted according to the PRISMA guidelines. Forty-four individual cases-non-neoplastic enlarged salivary glands (NNESG, n = 15), primary benign (n = 7) and malignant (n = 8) ectopic salivary tumours (ST) and sellar metastasis from eutopic primary ST (n = 14)-were suitable for the analysis of clinical, radiological and pathological characteristics. Therapeutic outcome was reviewed as a secondary endpoint.

RESULTS

All cases were diagnosed after surgery. NNESG commonly affected young and/or female patients, typically leading to headaches and hyperprolactinemia and originating close to the neurohypophysis. Submucosal SG should be excluded before concluding to an intrasellar NNESG after TS. No gender or age predominance was found for primary ectopic ST, which present as large tumors, with histological phenotypes similar to common ST. Hypopituitarism and diabetes insipidus were more frequent in ST than in NNESG. NNESG and benign ectopic ST rarely recur. Malignant ectopic ST should be distinguished from secondary localizations of eutopic ST reaching the sella by contiguity or metastatic spread; both share a frequent unfavorable outcome.

CONCLUSION

Sellar neoplasms derived from SG are rare but misleading conditions and pituitary dysfunction is likely to be more common than currently reported. Appropriate pathological evaluation and multidisciplinary approach are required.

Cystic sellar salivary gland-like lesions

Introduction: Cystic sellar salivary gland-like lesions (CSSLs) are exceedingly rare, with fewer than a dozen case reports. They contain amorphous colloid identical to Rathke cleft cyst contents, but the cyst wall additionally shows cohesive aggregates of benign salivary glands. We report three new examples. Materials and methods: Two cases were seen at University of Colorado Denver and one at Memorial Sloan Kettering (MSK). Molecular testing was attempted on two of three. Results: Case 1 is a 20-year-old female who presented with panhypopituitarism and was found to have a suprasellar mass that proved to be a CSSL. She received no postoperative adjuvant therapy, but recurrence of headaches and blurred vision 2 years later prompted return to medical attention. A much smaller local cyst recurrence was now accompanied by a thickened, bulbous infundibular stalk. Second resection yielded a gliotic infundibular stalk and amorphous mucin, but no residual salivary-like glands. She is without further recurrence on 6-year follow-up. Case 2 is a 29-year-old female with headache; while seen initially at a tertiary care center, diagnosis was only made after consultation at MSK. Case 3 is 68-year-old female who had originally presented with apoplexy to an outside hospital 7 years prior to surgery and diagnosis. Molecular testing was uninformative on case 1 and negative for mutations or fusions on case 3. Conclusion: Few pathologists or neuropathologists have encountered CSSLs in their practices; case 1 produced recurrence and significant infundibular stalk damage, and case 3 originally manifested apoplexy, features not previously reported.

Rathke's cleft-like cysts arise from Isl1 deletion in murine pituitary progenitors

The transcription factor ISL1 is expressed in pituitary gland stem cells and the thyrotrope and gonadotrope lineages. Pituitary-specific Isl1 deletion causes hypopituitarism with increased stem cell apoptosis, reduced differentiation of thyrotropes and gonadotropes, and reduced body size. Conditional Isl1 deletion causes development of multiple Rathke's cleft-like cysts, with 100% penetrance. Foxa1 and Foxj1 are abnormally expressed in the pituitary gland and associated with a ciliogenic gene-expression program in the cysts. We confirmed expression of FOXA1, FOXJ1, and stem cell markers in human Rathke's cleft cyst tissue, but not craniopharyngiomas, which suggests these transcription factors are useful, pathological markers for diagnosis of Rathke's cleft cysts. These studies support a model whereby expression of ISL1 in pituitary progenitors drives differentiation into thyrotropes and gonadotropes and without it, activation of FOXA1 and FOXJ1 permits development of an oral epithelial cell fate with mucinous cysts. This pituitary-specific Isl1 mouse knockout sheds light on the etiology of Rathke's cleft cysts and the role of ISL1 in normal pituitary development.

Primary Pituitary Adenoid Cystic Carcinoma: A Rare Salivary Gland-Like Tumor in the Sella

Adenoid cystic carcinoma (ACC) is a tumor of the exocrine glands that originates primarily from the minor and major salivary glands, nasopharynx, and lacrimal glands. ACC grows slowly but is locally aggressive and prone to recurrence. It is uncommon for ACCs to develop in the pituitary gland as a primary tumor. We present a case of primary pituitary ACC extending to the sphenoid sinus resembling an invasive adenoma in a 71-year-old woman with a history of nasal epistaxis. We reviewed other reported cases of pituitary ACCs with retrospective validation of whether the tumor was primary or not. The intrasellar tumor exhibited MYB rearrangement with enlargement and destruction of the sella turcica and dural tears toward the sphenoid sinus, which would be consistent for a tumor originating from the pituitary gland. Including our case, only four intrasellar and one suprasellar ACC have been confirmed as primary tumors. All intrasellar ACCs had the characteristic of some form of invasion of neighboring structures with evidence of hyperprolactinemia. ACC could develop in the pituitary gland as a form of salivary gland-like tumor derived from the ectopic salivary gland rests. ACCs rarely arise from the pituitary gland; however, the accurate determination of primary occurrence is difficult because of the invasive nature of these tumors, and the anatomical relationship with the sphenoid sinus and the cavernous sinus. Excessive bleeding from the tumor or unexpected internal carotid artery injury should be avoided during surgery for primary and secondary pituitary ACC.

Primary epithelial-myoepithelial carcinoma of the pituitary gland

Primary salivary gland-like tumors of the sella are rare and often challenging to diagnose. They reportedly derive from serous and mucinous glands that remain trapped in the infundibulum during embryogenesis. We report a 68-year-old man who presented with partial left third cranial nerve palsy, visual loss in the left eye without visual field defects, headache, weight loss and reduced muscle bulk. Neuroimaging studies demonstrated a solid and cystic, avidly enhancing lesion expanding the pituitary fossa and extending to the left cavernous sinus. The patient underwent craniotomy and the tissue removed showed features of epithelial-myoepithelial carcinoma similar to the salivary gland, skin and breast counterpart. No primary tumor was found outside the sella. The lesion behaved aggressively despite radio-chemotherapy and the patient died 22 months from the onset. The tumor showed a novel TP53 in-frame deletion (Gly154del) while no variants were found in H-RAS hotspot regions (codons 12, 13 and 61). Our report expands the spectrum of salivary gland-like tumors primarily occurring in the sella and emphasizes the need for specialist review of rare, non-neuroendocrine tumors of the pituitary and sella regions.

Intrasellar symptomatic salivary gland: case series and literature review

PURPOSE

Ectopic salivary glands have been found in both extracranial and intracranial locations, however, intrasellar symptomatic salivary gland is extremely rare and its clinical manifestation, radiological characteristics and outcome have not been systematically studied. Here we present a case series of intrasellar symptomatic salivary gland and perform a literature review to better characterize this disease.

METHODS

We retrospectively reviewed the data of three patients with intrasellar symptomatic salivary gland from our institutional and other cases available in literatures. Information for sex, age at diagnosis, clinical symptoms, radiological features, treatment strategy and prognosis were recorded.

RESULTS

A total of 11 cases (including our own) were identified. There were three men and eight women, with an average age at diagnosis of 28.3 years. The peak incidence was in the second and the third decade (72.7% of all cases). The most common symptom was headache (81.8% of all patients). About 63.6% patients had one or more abnormal hormone levels, and prolactin was likely the most vulnerable hormone. The radiological appearances of intrasellar salivary gland were various, and four cases mimicked pituitary adenoma radiologically. All patients underwent transsphenoidal surgery with no mortality.

CONCLUSION

Although intrasellar symptomatic salivary gland is rare, it should be considered in the differential diagnosis of intrasellar lesions. Preoperative diagnosis is challenging since it mimics pituitary neoplasm in clinical and radiological manifestations, and confirmation for this disease could only be conducted through pathological examination. Transsphenoidal surgical resection is the preferred therapy and the patient prognosis is usually good.

Mature salivary gland rests within sonic hedgehog-positive medulloblastoma: case report and insights into the molecular genetics and embryopathology of ectopic intracranial salivary gland analogs

Intracranial ectopic salivary gland rests within dural-based lesions are reported very infrequently in the literature. The authors report the unique case of a 12-year-old boy with a cerebellar medulloblastoma positive for sonic hedgehog (Shh) that contained intraaxial mature ectopic salivary gland rests. The patient underwent clinical and radiological monitoring postoperatively, until he died of disseminated disease. An autopsy showed no evidence of salivary glands within disseminated lesions. The intraaxial presence of salivary gland rests and concomitant Shh positivity of the described tumor point to a disorder in differentiation as opposed to ectopic developmental foci, which are uniformly dural based in the described literature. The authors demonstrate the characteristic "papilionaceous" appearance of the salivary glands with mucicarmine stain and highlight the role of Shh signaling in explaining the intraaxial presence of seromucous gland analogs. This article reports the first intraaxial posterior fossa tumor with heterotopic salivary gland rests, and it provides molecular and embryopathological insights into the development of these lesions.

Myoepithelioma of the Orbital Apex and Middle Cranial Fossa: Case Report and Review of the Literature

Myoepitheliomas are rare tumours that originate from glandular tissues such as the parotid or salivary glands, and less commonly from soft tissues of the head, neck, and other parts of the body. Intraorbital myoepitheliomas generally arise from the lacrimal gland. Intracranial myoepitheliomas are rare. We report a myoepithelioma of the orbital apex that did not originate from the lacrimal gland. It extended to the middle cranial fossa from the orbital apex and involved the dura and adjacent bone. A diagnostic biopsy via a lateral orbitotomy preceded resection. We review the natural course and histopathology of myoepithelial neoplasms, the surgical nuances of approaching an orbital apex tumour with maximal functional preservation, and the optimal management practices of these rare lesions.

Rapid-developed primary malignant myoepithelioma in the cavernous sinus: a case report

Background

Malignant myoepithelioma is a relatively rare malignant tumor occurring most frequently in the salivary glands. A few isolated cases have been described in other locations, including soft tissue, bone, lung, bronchus, oral cavity, nasopharynx, larynx, and maxillary sinus. Malignant myoepithelioma, however, is uncommonly involved within the cavernous sinus. To the best of our knowledge, this is the first report of malignant myoepithelioma arising from within the cavernous sinus.

Case presentation

Herein, we report a case of a 48-year-old woman who presented a 1-month history of diplopia and blepharoptosis as well as radiological evidence of a rapidly developing cavernous sinus tumor. The patient underwent a trans-sphenoidal biopsy and a histological diagnosis indicated a malignant myoepithelioma. After diagnosis, the tumor grew rapidly and her clinical condition deteriorated progressively. Therefore, a pterional craniotomy with partial tumor removal was performed. The patient’s clinical state was worsened, and she died two months after the initial operation. Because the malignant myoepithelioma could not be traced to an organ of origin, other than the cavernous sinus, this case was diagnosed as a primary intracranial malignant myoepithelioma.

Conclusion

The purpose of presenting this case report is to raise awareness among clinicians to consider malignant myoepithelioma as a differential diagnosis when a cavernous sinus mass is identified. Furthermore, an ideal management strategy for malignant myoepithelioma is not known and the prognosis seems to be unfavorable; therefore, more cases are needed to enhance our knowledge of the diagnosis, treatment, and prognosis of this rare intracranial lesion.

Pituitary symptomatic salivary gland rest cyst: case report

Although salivary gland rest in posterior pituitary is frequently observed during microscopic examination at autopsy, this rest tissue rarely causes clinical symptoms. So far, only three symptomatic salivary gland rest cyst in pituitary was reported. The author reports the 4^th case of symptomatic pituitary salivary gland rest cyst in 26-year-old woman presenting with severe headache. The lesion showed hyperdense shadow on computed tomography, high signal on T1-weighted image and low signal on T2-weighted image magnetic resonance imaging. There was no enhancement of the mass after gadolinium injection. Trans-sphenoidal approach revealed that the cyst wall consisted of normal appearing salivary gland and gelatinous cyst content. Although the pituitary salivary gland rest cyst is rarely symptomatic, it should be take into consideration in the differential diagnosis of pituitary lesions.

Metastasis of soft-tissue myoepithelial carcinoma to clivus

The differential diagnosis for masses involving the clivus is broad. The authors present a case of myoepithelial carcinoma metastatic to the clivus, a lesion that has not been reported to their knowledge. This 14-year-old girl with a history of myoepithelial carcinoma originating in the soft tissues of the left hip and metastatic to the lung presented with left lateral gaze palsy. Imaging demonstrated a 3 × 3-cm osteolytic mass in the clivus. Microscopic transsphenoidal resection with endoscopic assistance was performed. Pathological findings were consistent with the previously diagnosed myoepithelial carcinoma. Within 4 weeks postoperatively and 2 weeks into a chemotherapeutic regimen, the tumor exhibited progression. Radiation therapy was started and growth of the tumor was halted. Myoepithelial carcinoma should be included in the differential diagnosis for clival masses, especially in patients with previously diagnosed myoepithelial carcinoma. The primary management of this tumor should be with chemotherapy and radiation, with surgery serving only for decompression.

Intrasellar salivary gland-like pleomorphic adenoma: case report

BACKGROUND AND IMPORTANCE

We present a rare case of a patient with intrasellar salivary gland-like pleomorphic adenoma and review the 2 previously reported cases of the clinical entity to identify their common clinical features.

CLINICAL PRESENTATION

A 56-year-old Asian man visited our hospital with a chief complaint of visual disturbance caused by brain tumor that filled up the sella turcica with suprasellar extension. The patient underwent craniotomy via a left pterional approach, and the subdural, intracranial portion of the tumor was totally removed, with every artery and nerve preserved. Pathological diagnosis of the tumor was intrasellar salivary gland-like pleomorphic adenoma. Three years after the operation, the patient remains free from tumor recurrence.

CONCLUSION

Tumors in all 3 reported cases of intrasellar salivary gland-like pleomorphic adenoma, including the present case, showed suprasellar extension and compressed optic chiasm that resulted in visual disturbance of the patients. A calcified region inside the tumor on computed tomographic scanning was also a common finding. Differential diagnosis of intrasellar salivary gland-like pleomorphic adenomas should be considered in patients with calcified intrasellar tumors with suprasellar extension. The clinical entity seems to show good prognosis if surgically removed.

Primary adenomyoepithelioma of the sellar region: a case report

Small nests of an ectopic salivary gland tissue are clinically insignificant and they are an incidental finding at microscopic examination in various organs at autopsy. Intracranially, they are suggested to be the origin of extremely rare sellar tumors that bear a marked resemblance to tumors of the salivary gland. We report a case of 38-year-old man who presented with a sellar mass and partial visual loss. The tumor was surgically removed and microscopic examination showed a lesion consistent with adenomyoepithelioma as known in salivary gland pathology. After the surgery, the patient was administered substitution treatment for pan-hypopituitarism and diabetes insipidus. The neoplasm recurred 14 years after surgery in the same location. Transfrontal decompressive operation was followed by a transnasal procedure during which gross total removal of the tumor was achieved. The recurrent tumor displayed an identical morphology to the initial neoplasm; the only difference was an increase in the proliferative activity of the neoplastic cells in the recurrent growth. Six months after the surgery for the recurrent neoplasm, there are no clinical and radiological signs of tumor progression.

Intrasellar symptomatic salivary gland rest

Ectopic salivary gland tissue in sellar turcica is frequently observed in microscopic examination at autopsy. This tissue is considered clinically silent. Only 2 symptomatic cases have been previously reported. Here we report a 28-year-old woman presenting with galactorrhea and hyperprolactinemia. Magnetic resonance imaging revealed a 6 x 5-mm nodule in the posterior aspect of the pituitary gland. This nodule showed isointensity on T1- and T2-weighted images and less enhancement on post-contrast T1-weighted images. Transsphenoidal exploration revealed a cystic lesion within the pituitary gland, which consisted of a grayish gelatinous content. The pathologic examination confirmed the diagnosis of salivary gland rest.

Pre-morbid morphological conditions of the human pituitary

The clinically silent premorbid conditions of the pituitary, in particular preneoplastic features, were morphologically and statistically investigated within a control population at autopsy. A higher percentage of premorbid states were found, which was speculated to be a basis of possible later clinical lesions. They were as follows in 228 pituitary specimens: incidentalomas in 3% (potential pituitary adenomas), aberrant salivary gland cell clusters in the pars intermedia in 8.8% (potential salivary gland cysts or carcinomas in the sellar region), residual Rathke's cleft cells in 3.2-6.8% (potential craniopharyngiomas), meningothelial aggregates in the pituitary capsule in 4.0% (potential meningiomas), one case also had ciliated epithelial cell fragments in the anterior lobe, one case each of granular cell and nerve cell group in the posterior lobe, and two cases of telangiectasia. Furthermore, aberrant anterior pituitary cells were found in the leptomeniges of the peri-pituitary region as a possible basis of an intracranial ectopic pituitary adenoma. Silent premorbid conditions were not infrequently found (up to 8.8%). In particular, the "basis" of the possible neoplasm was pre-existent, so that some triggers are necessary (e.g., pituitary tumor transforming gene, hormonal stimuli, etc.) for it to become manifest, although there was no direct morphological evidence in our findings to alter to the lesions.

Pituitary tuberculoma: an unusual lesion of sellar region

Pituitary tuberculomas are extremely rare lesions, with only few cases described in the literature, usually mistaken as pituitary tumors. Its heterogeneous clinical and imaging profile preclude preoperative diagnosis which ultimately relies on the histopathological examination. We describe a 46 years old woman who presented with an episode of confusion and hypopituitarism with no evidence of systemic tuberculosis. Computed tomography (CT) showed a central calcified and enhancing sellar mass. Magnetic resonance imaging (MRI) showed a sellar mass with suprasellar extension and associated optic chiasm compression. She was submitted a craniotomy for biopsy and resection. A caseous material was found at the center of the lesion involved by a thick wall. Due to the wall adherence to the optic chiasm and the inflammatory aspects of the lesion, subtotal removal was achieved and the patient followed on anti-tuberculous and hormonal replacement therapy. Sellar tuberculomas should be considered in the differential diagnosis of sellar tumors in order to offer appropriate treatment.