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

Unusual Presentation of Craniopharyngioma Pituitary Mass in a 71-Year-Old Female: A Case Report

In this report, we present the case of a 71-year-old African-American woman experiencing 2 months of intermittent headaches and episodes of blurred vision. Despite a comprehensive medical history that revealed chronic conditions and previous unrelated surgeries, the initial evaluation appeared to be unremarkable. Following the discovery of a mass on an imaging and a subsequent biopsy, the diagnosis of craniopharyngioma (WHO grade I) was confirmed. However, a brain mass was identified after additional ophthalmologic examination and MRI. This case explores the significance of recognizing atypical presentations of a brain injury that required a specific approach for diagnosis, surgical intervention and treatment, and postoperative care. This case contributes to the constantly evolving understanding of atypical manifestations of tumor characteristics and their complexities, along with the need to develop appropriate patient management strategies and provide optimal outcomes.

Ectopic Pituitary Neuroendocrine Tumors/Adenomas Around the Sella Turcica

Functional or non-secretory ectopic pituitary neuroendocrine tumors (PitNET) can form around the sella turcica during the development of the adenohypophysis by differentiating and detaching from the pharyngeal roof. These tumors usually appear in the sphenoid sinus, clivus, cavernous sinus, infundibulum, and suprasellar cistern. Ectopic PitNETs typically display the characteristic magnetic resonance imaging findings of pituitary adenomas. However, preoperative diagnosis of PitNETs is usually challenging because of the variety of clinical and imaging presentations, locations, and sizes. Ectopic suprasellar PitNETs resemble mass lesions in the pituitary stalk. Ectopic cavernous sinus of PitNETs are typically microadenomas in the medial wall. Ectopic sphenoclival tumors are characterized by more aggressive tumor activity than the other ectopic PitNETs. Although ectopic PitNETs are exceedingly rare, they should be considered as a differential diagnosis for masses around the sella turcica. Treatment of the disease should be individualized and may include medical care, surgical resection, gamma-knife radiosurgery, and radiotherapy.

Top IHC/ISH Hacks for and Molecular Surrogates of Poorly Differentiated Sinonasal Small Round Cell Tumors

BACKGROUND

Poorly differentiated sinonasal small round cell tumors (SRCTs) are rare and heterogeneous, posing challenges in diagnosis and treatment.

METHODS

Recent advances in molecular findings and diagnostic refinement have promoted better understanding and management of these tumors.

RESULTS

The newly defined and emerging sinonasal entities demonstrate diverse morphologies, specific genomic signatures, and clinical behavior from conventional counterparts. In this review of SRCTs, emphasis is placed on the diagnostic approach with the employment of a pertinent panel of immunohistochemistry studies and/or molecular tests, fine-tuned to the latest WHO 5 classification of sinonasal/paranasal tumors and personalized treatment.

CONCLUSION

Specifically, this review focuses on tumors with epithelial and neuroectodermal derivation.

Ectopic pituitary adenoma with empty sella: A case report

Ectopic pituitary adenoma is a condition characterized by the presence of an adenoma originating from extra-sellar pituitary cell residue from the migration of Rathke's pouch. First described in 1909, ectopic pituitary adenoma is a very rare, largely unknown condition with a challenging diagnosis, that requires proving the absence of communication between the extra-sellar mass and the normal pituitary gland (or any of the intra-sellar contents). Here, we describe the case of a 38-year-old female who presented with symptomatic hyperprolactinemia in whom magnetic resonance imaging revealed a space-occupying mass in the sphenoid sinus with an empty sella turcica. Clinical information coupled with magnetic resonance imaging findings raised suspicion for the diagnosis, which was later confirmed through surgery (showing the absence of a breach in the sellar floor dura), and histology. Given the rarity of such cases, management is not standardized; however, most patients reported in the literature, as in our case, have undergone surgical treatment. This case report aims to provide an additional example to the existing literature on this rare condition, especially when it is associated with an empty sella turcica.

IgG4-negative pituitary inflammatory pseudotumor with sphenoidal involvement resembling a macroadenoma

BACKGROUND

Inflammatory pseudotumors (IPTs) are rare benign conditions of unknown etiology that can affect any part of the body. IPTs are most commonly associated with Immunoglobulin G4 (IgG4)-related disease. Central nervous system IPTs, especially with pituitary involvement, are even rarer entities. The presence of an IgG4-negative pituitary IPT with simultaneous extracranial involvement has not been reported.

CASE REPORT

We present the case of a 41-year-old female with past medical history of rheumatoid arthritis and a diagnosis of pituitary IPT with coexisting sphenoidal (extracranial) involvement mimicking a pituitary macroadenoma at presentation. The patient underwent multiple consecutive biopsies, and an extensive workup prior to establishing the diagnosis. Laboratory work-up showed normal serum IgG4 and unremarkable liver function tests.

CONCLUSION

Pituitary lesions with simultaneous sphenoidal involvement in patients with IgG4-negative systemic inflammatory disease should raise the clinical suspicion for intracranial IPTs, as these tumors can mimic aggressive counterparts causing adjacent bony erosion, and local invasion.

Clival ectopic pituitary prolactinoma was successfully managed by transsphenoidal surgery: A rare case report

Key Clinical Message

Ectopic pituitary adenoma is a rare neoplasm located in the clivus and could mimic other clival tumors. Diagnosis and treatment could be challenging. It should be considered in the differential diagnosis of clival tumors.

Abstract

Ectopic pituitary adenomas (EPAs) are isolated adenomas that can be located in variable locations outside the sella turcica and have a normal-appearing pituitary gland. These tumors are rare and are thought to often arise from embryological remnants along the route of Rathke's pouch migration. EPAs are associated with a wide range of clinical manifestations depending on hormonal activity and involvement of adjacent structures, which can represent a challenge in making the diagnosis and deciding on the most appropriate management. In this case study, we report a 47-year-old male who presented with visual disturbances, a headache, and generalized weakness. Magnetic resonance imaging showed a 2 cm mass located in the clivus invading the sphenoid sinus with an intact pituitary gland. The patient underwent endoscopic transsphenoidal surgery to eradicate the mass while maintaining the integrity of the pituitary gland, which was successful and uneventful. Pathological studies were consistent with prolactinoma, with no cytological malignant features. Post-surgery, symptoms notably improved, and serum prolactin levels significantly dropped, The patient's condition was satisfactory on follow-up with no long-term complications reported. This paper contributes to the existing literature by sharing the clinical management of a challenging and uncommon case.

Null-Cell Ectopic Pituitary Adenoma of the Nasal Cavity

An ectopic pituitary adenoma (EPA) is an uncommon type of pituitary adenoma, accounting for only 2% of all pituitary adenomas. EPAs are benign tumors that can occur anywhere along the migratory embryonic path of the pituitary gland and have no relationship to intrasellar elements. They are usually hormonally active and have a minor female predominance. The clinical features of EPAs are highly dependent on its hormonal activity, anatomical location, and its local mass effect. Appropriate radiological imaging is essential for the evaluation of EPAs. Imaging investigations show a normal pituitary gland and sellar turcica, provide details on the size of the tumor, its margins, and extent, and help with surgical planning. The criteria for diagnosing an ectopic pituitary adenoma depend on detailed histopathological examination. EPA management should be individualized. We present a case of a 71-year-old male who presented with a 9-month history of left nasal obstruction, purulent nasal discharge, and intermittent anterior epistaxis. The patient was being managed by his general practitioner for chronic rhinosinusitis but failure of his symptoms to resolve prompted a visit to the otorhinolaryngologist. The patient was diagnosed with a null-cell ectopic pituitary adenoma through histological analysis of a biopsy specimen that showed adenohypophyseal cells without cell-type-specific differentiation. The patient subsequently underwent an endoscopic endonasal excision and had an uneventful hospital stay.

Ectopic Pituitary Neuroendocrine Tumor: A Case Report Written With the Help of ChatGPT

ChatGPT (Chat Generative Pre-trained Transformer) is a chat robot program developed by OpenAI (OpenAI Incorporated, Mission District, San Francisco, USA). It is a natural-language processing tool driven by artificial intelligence technology. It can complete tasks such as writing emails, video scripts, copywriting, translation, coding, and writing papers. At present, several studies have been conducted on the use of this tool for academic writing, so we report a rare case of suprasellar ectopic pituitary neuroendocrine tumor (PitNET) secreting growth hormones, in a female 53-year-old patient with facial changes and hypertrophy of her hands and feet for six years. When asking questions on unusual topics, ChatGPT can provide answers but not specific ones, and similar to most machine learning solutions, verifying the correctness of information is a problem. Question asked from ChatGPT: Summarize ectopic pituitary neuroendocrine tumor. "Suprasellar heterotopic pituitary neuroendocrine tumors refer to tumors formed by the heterotopic growth of pituitary neuroendocrine tumor cells in the sellar region other than the pituitary glands. This tumor is common in middle-aged women, and it often manifests as headache, visual impairment, and endocrine dysfunction. Diagnosis is usually made by combining history, physical examination, blood tests, and imaging. Treatment is primarily performed through surgical resection of the tumor, radiotherapy, and drug therapy, and the prognosis is mostly good." The content in quotation marks is generated by ChatGPT.

A study on H-score threshold for p16ink4a immunoperoxidase expression in squamous cell tumours of oral cavity

Background

Validity of various detection methods used are likely contributing factor to this wide variation of prevalence of HPV (0-73%) by using GP5/GP6/MY09/MY11 (L1) primer. PCR is a sensitive method but does not identify transcriptionally active High-risk Human papillomavirus and also does not indicate whether the virus is isolated from malignant tumour cells and non-neoplastic cells. P16ink4a Immunohistochemistry is a highly sensitive and Cost-effective surrogate marker for transcriptionally active high-risk HPV for oral cancer. Objective The aim of the present study was to evaluate the H-SCORE of p16 expression in the surface epithelial tumour sites of a large cohort of squamous cell carcinoma (SCC), severe dysplasia (SD). we sought to determine whether the p16 algorithm is reliable in Oral cavity SCC and severe dysplasia (SD).

Materials and Methods

This study used Immunohistochemistry in archival Formalin-fixed paraffin embedded specimens for assessment of p16 protein expression, cytoplasmic and nuclear staining intensity was categorized based on score (range, 0-3) and presence of tumour cell staining (0-100%).

Results

The majority of positive cases had low H-score of p16 staining except 3/161 (1.8%) cases of tongue SCC had positive for p16 with diffuse moderate staining with ≥2 scores. There were no significant differences in the distribution of demographic, exposure and histopathological characteristics between patients with and without P16 expression.

Conclusion

The present study demonstrated that p16 expression is a reliable HPV marker in the lateral border of the tongue with tonsil involvement but no other sites of the oral cavity. Further p16 IHC detection is required in large cohort of all sites of tongue squamous cell carcinoma studies to validate the marker of HPV.

Top 10 Nested Pattern Head and Neck Lesions to Notice

BACKGROUND

Nested is defined as "cellular clusters arranged in small groupings with intervening vascular or stromal networks, lacking lumens or glandular formation." Using this definition, multiple neoplastic and non-neoplastic lesions of the head and neck come into the differential. We have broadly organized the differential diagnosis of "nested" tumors into entities with neuroendocrine differentiation, squamous differentiation, thyroid follicular cell differentiation, and other lesions.

METHODS

Review.

RESULTS

Many different entities have a nested appearance and the morphologic, immunohistochemical, clinical, and radiographic features contribute to the differential diagnosis. The different tumors covered in this review include neuroendocrine neoplasms, paraganglioma, middle ear neuroendocrine tumor (formerly known as middle ear adenoma), medullary thyroid carcinoma, poorly differentiated thyroid carcinoma, olfactory neuroblastoma, ectopic pituitary neuroendocrine tumor, hyalinizing trabecular tumor, solid subtype of papillary thyroid carcinoma, solid cell nests/C-cell hyperplasia, necrotizing sialometaplasia, and meningioma.

CONCLUSION

In this review, we discuss the morphologic and immunohistochemical features of the covered entities as a guide to differential diagnosis when nested-patterned head and neck lesions are encountered.

Predictive Value of Anti- E6 Oncoprotein (High Risk- Human Papilloma Virus) and p16 Ink4a for Detecting HPV in Oral Epithelial Dysplasia

AIM

The aim of this study was to evaluate the expression of human papillomavirus (HPV) in oral potentially malignant disorders (OPMD) and to examine the association of HPV in histological grades of dysplasia using p16 and Anti-E6 oncoprotein immunohistochemistry (IHC).

SUBJECTS AND METHODS

This study focused on clinically diagnosed oral potentially malignant disorders. Clinical parameters such as age, gender, habits, occupation, duration, site, and the type of the lesions were examined and the incisional biopsy was done on the selected cases for the histopathological diagnosis. Selected cases of OPMDs were screened immunohistochemically for HPV 16 and HPV 18 (high-risk group) positivity using p16INK4a and Anti-E6 oncoprotein. The immunohistochemical p16 expression was evaluated based on (a) percentage of p16 positive cases and (b) pattern of p16 staining in various grades of OPMD.

RESULTS

Anti-E6 oncoprotein (HR-HPV) expression level was only detected in 11 cases (37%), and positive expression of p16 was found in three cases (10%), with variation in cell proportion and intensity. Subsequently, the association between p16 expression level and clinicopathological characteristic factors was analyzed and a significant association was found between age and histopathology.

CONCLUSION

There was an association between HPV and OPMD. Both biomarker tests, HPV E6 and p16 immunocytochemistry had a specific role in the detection of HR-HPV. Anti-E6 immunocytochemistry can be a valuable test with higher specificity for HPV DNA detection in oral epithelial dysplasia without losing sensitivity.

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.

MRI-negative Cushing's Disease: Management Strategy and Outcomes in 15 Cases Utilizing a Pure Endoscopic Endonasal Approach

BACKGROUND

Cushing's disease (CD) is among the most common etiologies of hypercortisolism. Magnetic resonance imaging (MRI) is often utilized in the diagnosis of CD, however, up to 64% of adrenocorticotropic hormone (ACTH)-producing pituitary microadenomas are undetectable on MRI. We report 15 cases of MRI negative CD who underwent surgical resection utilizing a purely endoscopic endonasal approach.

METHODS

Endoscopic endonasal transsphenoidal surgery (EETS) was performed on 134 CD cases by a single surgeon. Fifteen cases met inclusion criteria: no conclusive MRI studies and no previous surgical treatment. Data collected included signs/symptoms, pre- and post-operative hormone levels, and complications resulting from surgical or medical management. Data regarding tumor diameter, location, and tumor residue/recurrence was obtained from both pre- and post-operative MRI. Immunohistochemistry was performed to assess for tumor hormone secretion.

RESULTS

Aside from a statistically significant difference (P = 0.001) in histopathological results between patients with negative and positive MRI, there were no statistically significant difference between these two groups in any other demographic or clinical data point. Inferior petrosal sinus sampling (IPSS) with desmopressin (DDAVP®) administration was performed on the 15 patients with inconclusive MRIs to identify the origin of ACTH hypersecretion via a central/peripheral (C/P) ratio. IPSS in seven, five and three patients showed right, left, and central side lateralization, respectively. With a mean follow-up of 5.5 years, among MRI-negative patients, 14 (93%) and 12 patients (80%) achieved early and long-term remission, respectively. In the MRI-positive cohort, over a mean follow-up of 4.8 years, 113 patients (94.9%) and 102 patients (85.7%) achieved initial and long-term remission, respectively.

CONCLUSIONS

Surgical management of MRI-negative/inconclusive Cushing's disease is challenging scenario requiring a multidisciplinary approach. An experienced neurosurgeon, in collaboration with a dedicated endocrinologist, should identify the most likely location of the adenoma utilizing IPSS findings, followed by careful surgical exploration of the pituitary to identify the adenoma.

Primary Tumors of the Pituitary Gland: Radiologic-Pathologic Correlation

Primary tumors of the pituitary gland are the second most common histologic category of primary central nervous system tumors across all age groups and are the most common in adolescents to young adults, despite originating from a diminutive endocrine gland that is often described as "about the size of a pea." The vast majority of these represent primary tumors of the adenohypophysis, specifically pituitary adenomas, which can be either functional or silent with regard to hormone hypersecretion. According to the fourth edition of the World Health Organization classification of endocrine tumors, published in 2017, cellular lineage and immunohistochemical stains for pituitary hormones and/or transcription factors help with making the correct pathologic diagnosis. From a radiologic standpoint, microadenomas pose challenges for accurate detection and avoiding false-negative or false-positive results, while macroadenomas pose challenges from local mass effect on surrounding structures. Pituitary carcinoma and pituitary blastoma also arise from the adenohypophysis and are characterized by metastatic disease and infantile presentation, respectively. While primary tumors of the adenohypophysis are common, a second category comprising primary tumors of the Rathke pouch (ie, craniopharyngioma) are uncommon, and a third category comprising primary tumors of the neurohypophysis (eg, pituicytoma) are rare. The authors review all three categories of pituitary tumors, with emphasis on radiologic-pathologic correlation, including the typical neuroimaging, histologic, and molecular features that may point toward a specific diagnosis. Work of the U.S. Government published under an exclusive license with the RSNA.

Neuropathology of Pituitary Adenomas and Sellar Lesions

The pituitary gland is the site of numerous neoplastic and inflammatory processes. The overwhelmingly most frequent tumors arise from cells of the anterior lobe, the pituitary neuroendocrine tumors (PitNETs). Immunohistochemistry assay staining for pituitary hormones is the core tool for classifying PitNETs, resulting in the diagnosis of somatotroph PitNETs, lactotroph PitNETs, and so on. For cases showing no hormonal expression, the updated WHO classification system now considers the assessment of several transcription factors: PIT-1 (pituitary-specific POU-class homeodomain transcription factor); T-PIT (T-box family member TBX19); and SF-1 (steroidogenic factor regulating gonadotroph cell differentiation) before rendering a diagnosis of null cell adenoma. Other tumors and disease processes of this site often mimic PitNETs radiographically and sometimes even clinically (ie, compression of the optic chiasm). These potpourri of processes include germ cell neoplasms (especially germinomas), tumors that originate from Rathke's pouch (craniopharyngiomas, Rathke's cleft cyst), tumors that originate from the posterior lobe of the pituitary (pituicytoma, spindle cell oncocytoma, granular cell tumor), and tumors that originate from the meninges (especially meningiomas). In addition to neoplasms, several described inflammatory and related conditions exist that need to be distinguished from PitNETs. These include lymphocytic hypophysitis and Langerhans cell histiocytosis, a neoplastic disorder of histiocytes. In this review, we aim to briefly describe the main pituitary and sellar lesions, with emphasis on the most common tumors, the PitNETs.

A case of hyperprolactinaemia in a patient with metastatic melanoma

Ectopic prolactin production from a malignancy is infrequently reported. We report here a 60-year-old gentleman who presented with hyperprolactinaemia (9100 mIU/L) causing expressible galactorrhoea, decreased libido and fatigue thought to be due to ectopic prolactin secretion from a metastatic melanoma. Upon initiation of pembrolizumab, the patient's symptoms resolved and he became normoprolactinaemic. This corresponded with a partial response on radiological imaging. Although the core biopsy of the metastatic melanoma did not exhibit immunostaining for prolactin, we believe that only a subset of the tumour cells possesses prolactin-secreting capacity. This case illustrates the need to consider ectopic prolactin production for a solid malignant tumour as a rare cause of hyperprolactinaemia in patients with a normal pituitary MRI, in the absence of other causes.

Lobular to Lobule: Metastatic Breast Carcinoma to Olfactory Neuroblastoma

Tumor-to-tumor metastasis (TTM) is a rare, but well-described phenomenon occurring in patients with multiple synchronous or metachronous primary malignancies. Olfactory neuroblastoma (ONB) is a rare malignant, neuroectodermal sinonasal tract tumor that occurs within the ethmoid sinus involving the cribriform plate. Very few cases of ONB have been documented to metastasize to other primary malignancies, but the reverse scenario is exceptional. During an evaluation for anosmia, a right nasal polyp was identified on imaging and endoscopy in a 66-year-old woman, with a polypectomy performed. Histologic examination showed classical features of a low-grade olfactory neuroblastoma, but within the tumor were isolated epithelioid cells which were strongly pancytokeratin immunoreactive. Review of the clinical history revealed lobular breast carcinoma treated 10 years earlier. Further evaluation with immunohistochemistry showed strong and diffuse nuclear estrogen and progesterone receptor reactivity, along with GATA3. These results confirmed TTM of an invasive lobular breast carcinoma to ONB. By employing a limited immunohistochemistry panel for all small round blue cell tumors that includes pancytokeratin, p40, S100 protein, SOX10, synaptophysin, desmin, CD99, and CD45, one is able to more accurately diagnose the classical tumor types, while also showing potentially unusual tumor features or exceptionally rare events like metastatic lobular breast carcinoma to ONB.

Ectopic sphenoid sinus pituitary adenoma masquerading as metastatic head and neck cancer

A 68-year-old Chinese man was found to have a lobular mass in the sphenoid sinus which extended to the clivus and the roof of the nasopharynx on a staging MRI scan performed for his high-grade parotid salivary duct carcinoma. Further positron emission tomography scan showed that this lesion was fluorodeoxyglucose (FDG) avid. This proved to be a diagnostic dilemma. The patient underwent a total parotidectomy, left selective neck dissection and a transphenoidal biopsy of his nasal lesion. Final histology revealed that this lesion was a synchronous ectopic sphenoid sinus pituitary adenoma (ESSPA). Initial differential diagnoses that were considered included a chordoma, metastatic carcinoma and nasopharyngeal carcinoma. However, an important differential with a neoplastic appearance and a tendency for positive FDG uptake is an ESSPA. It requires dedicated immunohistochemical staining to diagnose, and its mainstay of treatment is surgical excision.

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.

Pituitary tumors: epidemiology and clinical presentation spectrum

Pituitary tumors (PTs) are a heterogeneous group of lesions of the central nervous system that are usually benign. Most of them occur sporadically, but 5% can do so within family syndromes, usually at a young age. There are differences by sex, age, race, and genetic factors in the prevalence of different tumor cell types and clinical presentation. Functioning-PTs (FPTs) are usually diagnosed earlier than non-functioning PTs (NFPTs). However, this depends on the PT type. Headaches and visual disturbances are the most frequent mass-effect symptoms, but seizures or hydrocephalus may also occur. Pituitary apoplexy is another possible mode of presentation, and it requires special attention because of its potential severity. PTs in pregnancy, childhood, and old age present a series of clinical peculiarities that must be taken into account when evaluating these patients. Ectopic PTs (EPTs) are uncommon and share the same clinical-epidemiological data as eutopic PTs, but, depending on their location, other types of clinical manifestations may appear. Silent PTs are often detected as an incidentaloma or due to neurologic symptoms related to mass-effect. Aggressive PTs and pituitary carcinomas (PCs), which are very rare, are characterized by multiple local recurrences and metastases, respectively. This review addresses the epidemiology and clinical presentation of PTs, from the classical hormonal and mass-effect symptoms to the different rare presentations, such as pituitary apoplexy, hydrocephalus, or diabetes insipidus. Moreover, special situations of the presentation of PTs are discussed, namely, PTs in pregnancy, childhood, and the elderly, EPTs, silent and aggressive PTs, and PCs.

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.

FDG PET/CT Findings of Ectopic Pituitary Adenoma

A 72-year-old woman had undergone a right mastectomy for breast cancer 3 years earlier. PET/CT revealed a tumor with bony destruction of the skull base and FDG accumulation (SUVmax, 7.86). MRI showed the well-circumscribed tumor in the sphenoid sinus. The possibility of bone metastasis could not be denied. Tumor removal surgery was performed; the tumor was separate from the normal pituitary gland, and an ACTH-producing ectopic pituitary adenoma was diagnosed pathologically.

Ectopic pituitary adenoma of the TSH-secreting sphenoidal sinus with excellent response to somatostatin analogs. Theory of the embryogenesis and literature review from a clinical case

Ectopic thyrotropin-secreting pituitary adenomas are rare, with only 10 published cases. We report the case of a 52-year-old woman who was referred for primary hypothyroidism, who showed clinical signs of hyperthyroidism and had been under treatment with levothyroxine. Her exams revealed high levels of thyroid stimulating hormone (TSH), at odds with free thyroxin (FT4) and raised triiodothyronine (T3), which remained elevated after medication suspension, suggesting possible central hyperthyroidism. Sellar MRI showed normal pituitary gland, with a mass in the sphenoid sinus of 24 mm. A possible ectopic TSH secreting pituitary tumor of sphenoid sinus was hypothesized. After a intramuscularly (IM) single dose of a sustained-relase of a somatostatin analog (octreotide) 20 mg, plasma levels of thyroid hormones were normalized and a significant tumor reduction was demonstrated in MRI control at 7-weeks' follow-up. The tumor was removed by transsphenoidal endoscopy, and the biopsy confirmed an adenoma with positive immunostaining for TSH and GH. Hyperthyroidism recurrence was observed in hormonal controls 4 weeks after surgery. Treatment with sustained-release octreotide was reinitiated, every 60-days for two years, with normalization of the thyroid hormone profile, but with a residual lesion with the appearance of a tumor in the MRI. A second tumor resection was performed, achieving sustained hormonal cure and no residual tumor lesion at 2-years' follow-up. To our knowledge, this is the first report of an ectopic thyrotropin-secreting pituitary adenoma of the sphenoid sinus. Clinical and laboratory aspects relevant to this entity are reviewed, emphasizing the usefulness of octreotide in the management of the reported case.

Diagnosis and Treatment of Parasellar Lesions

The parasellar region, located around the sella turcica, is an anatomically complex area representing a crossroads for important adjacent structures. Several lesions, including tumoral, inflammatory vascular, and infectious diseases may affect this area. Although invasive pituitary tumors are the most common neoplasms encountered within the parasellar region, other tumoral (and cystic) lesions can also be detected. Craniopharyngiomas, meningiomas, as well as Rathke's cleft cysts, chordomas, and ectopic pituitary tumors can primarily originate from the parasellar region. Except for hormone-producing ectopic pituitary tumors, signs and symptoms of these lesions are usually nonspecific, due to a mass effect on the surrounding anatomical structures (i.e., headache, visual defects), while a clinically relevant impairment of endocrine function (mainly anterior hypopituitarism and/or diabetes insipidus) can be present if the pituitary gland is displaced or compressed. Differential diagnosis of parasellar lesions mainly relies on magnetic resonance imaging, which should be interpreted by neuroradiologists skilled in base skull imaging. Neurosurgery is the main treatment, alone or in combination with radiotherapy. Of note, recent studies have identified gene mutations or signaling pathway modulators that represent potential candidates for the development of targeted therapies, particularly for craniopharyngiomas and meningiomas. In summary, parasellar lesions still represent a diagnostic and therapeutic challenge. A deeper knowledge of this complex anatomical site, the improvement of imaging tools, as well as novel insights into the pathophysiology of presenting lesions are strongly needed to improve the management of parasellar lesions.

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.

Isolated Sphenoid Sinus Lesions: Experience with a Few Rare Pathologies

INTRODUCTION

The sphenoid sinus is often neglected because of its difficult access. The deep position of the sphenoid sinus hinders early diagnosis of pathologies in that location. Delayed diagnosis can cause serious complications due to proximity to many important structures.

OBJECTIVES

The aim of this study is to demonstrate different pathologies which can affect the sphenoid sinus and elucidate the findings.

METHODS

Cases of isolated sphenoid sinus lesions encountered in the neurosurgical setting which had rare pathologies are discussed. Pathologies such as Langerhans cell histiocytosis, solitary plasmacytoma, chordoma, pituitary adenoma, leiomyosarcoma, fungal infection, and mucocele which appeared primarily in sphenoid sinus are discussed along with their imaging features and pathological findings.

CONCLUSION

Multitude of different pathologies can occur in sphenoid sinus. Detailed preoperative imaging is very helpful, but transnasal biopsy and histological study are required often for definitive diagnosis. The possible advantages of early diagnosis before spread of pathology for prognosis cannot be overemphasized.

[Neuroendocrine neoplasms of the auditory, olfactory, and visual sensory organs]

Neuroendocrine neoplasms (NENs) are infrequent in sensory organs. There are well-differentiated neuroendocrine neoplasms that should be classified as neuroendocrine tumors, in analogy to their gastrointestinal counterparts, however the nomenclature is inconsistent. The best defined entities are neuroendocrine tumors in the middle ear and ectopic pituitary adenoma in the sphenoid region. Poorly differentiated NENs most often arise in the olfactory organ and nasal cavity that are represented by olfactory neuroblastomas and poorly differentiated neuroendocrine carcinomas. They have several mimickers such as the sinonasal undifferentiated carcinoma, poorly differentiated squamous cell carcinoma, mucosal malignant melanoma, rhabdomyosarcoma, Ewing sarcoma/primitive neuroectodermal tumor and non-Hodgkin lymphoma.

Ectopic pituitary adenomas: common presentations of a rare entity

PURPOSE

Ectopic pituitary adenomas (EPA) are rare tumors thought to arise from embryological remnants along the route of normal pituitary migration. Clinically, these tumors vary in hormonal activity and can exert mass effect based on location and size.

METHODS

We performed a single-center retrospective analysis of patients with diagnosis of ectopic pituitary adenoma from 2001 to 2018.

RESULTS

Five patients were identified with EPA: a 48-year-old woman with suprasellar EPA treated with transsphenoidal removal of the tumor, a 44-year-old woman with cavernous EPA treated with transsphenoidal removal of the tumor, a 48-year-old woman with sphenoid EPA treated with cabergoline, a 45-year-old man with clival EPA treated with cabergoline and transsphenoidal surgical resection, and a 54-year-old man with clival EPA treated with cabergoline therapy.

CONCLUSIONS

EPA should be considered as a differential diagnosis of juxta-sellar lesions. Appropriate hormonal testing may lead to early diagnosis, avoidance of unnecessary biopsy or surgery, and improved outcomes.

GATA3 immunoreactivity expands the transcription factor profile of pituitary neuroendocrine tumors

The modern classification of pituitary neuroendocrine tumors relies mainly on immunohistochemistry for pituitary transcription factors, hormones, and other biomarkers, including low molecular weight cytokeratins. The transcription factor GATA2 is required for development of gonadotrophs and thyrotrophs but has not been used for classification of pituitary tumors. Because of genomic paralogy of GATA2 and GATA3, we postulated that GATA3 immunohistochemistry may detect GATA2 in the adenohypophysis. We examined 151 tumors originating from Ondokuz Mayis University, Turkey (n = 83) and University Health Network, Canada (n = 68). Initially, 83 tumors (26 gonadotroph, 24 somatotroph, 17 corticotroph, 12 lactotroph, 2 poorly differentiated Pit-1 lineage tumors that expressed TSH and 2 null cell tumors) from Ondokuz Mayis University were investigated with the GATA3 monoclonal antibody L50-823. Retrospective review of the files of University Health Network identified 68 tumors (43 gonadotroph, 3 somatotroph, 2 lactotroph, 1 mammosomatotroph, 9 corticotroph, 7 poorly differentiated Pit-1 lineage tumors with TSH expression, 2 plurihormonal tumors with TSH expression and 1 null cell tumor) that were examined with the same GATA3 antibody and served as a validation cohort. All somatotroph, lactotroph and mammosomatotroph tumors and the null cell tumors were negative for GATA3. Sixty-eight (98.5%) gonadotroph tumors were positive for GATA3; 64 had diffuse reactivity. Two plurihormonal tumors with TSH expression and eight (88.8%) poorly differentiated Pit-1 lineage tumors with variable TSH expression were positive for GATA3. One of 26 (3.8%) corticotroph tumors was diffusely positive for GATA3. This study shows that GATA3 immunoreactivity is characteristic of pituitary gonadotroph and TSH-producing tumors. This finding expands the pattern of transcription factors that are used to classify adenohypophysial tumors and is important in the differential diagnosis of sellar tumors, as GATA3 expression is also a feature of primary sellar paragangliomas as well as carcinomas that may metastasize to the sella.

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.

DNA methylation-based reclassification of olfactory neuroblastoma

Olfactory neuroblastoma/esthesioneuroblastoma (ONB) is an uncommon neuroectodermal neoplasm thought to arise from the olfactory epithelium. Little is known about its molecular pathogenesis. For this study, a retrospective cohort of n = 66 tumor samples with the institutional diagnosis of ONB was analyzed by immunohistochemistry, genome-wide DNA methylation profiling, copy number analysis, and in a subset, next-generation panel sequencing of 560 tumor-associated genes. DNA methylation profiles were compared to those of relevant differential diagnoses of ONB. Unsupervised hierarchical clustering analysis of DNA methylation data revealed four subgroups among institutionally diagnosed ONB. The largest group (n = 42, 64%, Core ONB) presented with classical ONB histology and no overlap with other classes upon methylation profiling-based t-distributed stochastic neighbor embedding (t-SNE) analysis. A second DNA methylation group (n = 7, 11%) with CpG island methylator phenotype (CIMP) consisted of cases with strong expression of cytokeratin, no or scarce chromogranin A expression and IDH2 hotspot mutation in all cases. T-SNE analysis clustered these cases together with sinonasal carcinoma with IDH2 mutation. Four cases (6%) formed a small group characterized by an overall high level of DNA methylation, but without CIMP. The fourth group consisted of 13 cases that had heterogeneous DNA methylation profiles and strong cytokeratin expression in most cases. In t-SNE analysis, these cases mostly grouped among sinonasal adenocarcinoma, squamous cell carcinoma, and undifferentiated carcinoma. Copy number analysis indicated highly recurrent chromosomal changes among Core ONB with a high frequency of combined loss of chromosome 1-4, 8-10, and 12. NGS sequencing did not reveal highly recurrent mutations in ONB, with the only recurrently mutated genes being TP53 and DNMT3A. In conclusion, we demonstrate that institutionally diagnosed ONB are a heterogeneous group of tumors. Expression of cytokeratin, chromogranin A, the mutational status of IDH2 as well as DNA methylation patterns may greatly aid in the precise classification of ONB.

[Ectopic pituitary adenoma associated with empty sella turcica]

Ectopic pituitary adenoma is a rare entity that is most commonly located in the sphenoid sinus. We report a case of a patient with ectopic pituitary adenoma with no functional expression associated with empty sella turcica, which gives rise to a broad differential diagnosis. Although it is a benign neoplasm, necrosis is encountered in a proportion of cases. Magnetic resonance imaging is the diagnostic method of choice for hypothalamic-pituitary-related endocrine diseases with endoscopic biopsy for histological confirmation. It is important to include pituitary markers in the immunohistochemical diagnostic panel.

Sinonasal Neuroendocrine Neoplasms: Current Challenges and Advances in Diagnosis and Treatment, with a Focus on Olfactory Neuroblastoma

Sinonasal tumors with neuroendocrine differentiation form a group of rare heterogeneous neoplasms of neuroectodermal and epithelial origin, consisting of olfactory neuroblastomas and neuroendocrine carcinomas. Because the natural history and biological behavior of this group of tumors vary, the morphological diagnosis coupled with grading/staging is important for prognostication, and the approach to treatment and rehabilitation is multidisciplinary. The identification of molecular abnormalities underlying these tumors is critical to the development of specific targeted therapies and the design of clinical trials.

Sinonasal Tract Alveolar Rhabdomyosarcoma in Adults: A Clinicopathologic and Immunophenotypic Study of Fifty-Two Cases with Emphasis on Epithelial Immunoreactivity

Sinonasal tract (SNT) alveolar rhabdomyosarcoma (ARMS) are frequently misdiagnosed, especially in adults. Fifty-two adult (≥18 years) patients with SNT ARMS were reviewed and characterized by immunohistochemistry and molecular studies. Twenty-six females and 26 males (18-72 years; mean 43.2 years), presented after a short duration (mean 2.6 months) with a large (mean 5.5 cm) destructive nasal cavity mass, involving multiple contiguous paranasal sites (n = 46) and with cervical adenopathy (n = 41). The tumors showed an alveolar, nested to solid growth pattern below an intact, but often involved (n = 9) epithelium with frequent necrosis (n = 37), destructive bone invasion (n = 30), and lymphovascular invasion (n = 25). The neoplastic cells were dyshesive and dilapidated, with crush artifacts. Rhabdoid features (n = 36) and tumor cell multinucleation (n = 28) were common. Mitotic counts were high (mean 17/10 HPFs). The neoplastic cells showed the following immunohistochemical positive findings: desmin (100%), myogenin (100%), MYOD1 (100%), MSA (96%), SMA (52%), CAM5.2 (50%), AE1/AE3 (36%); other positive markers included S100 protein (27%), CD56 (100%), synaptophysin (35%), and chromogranin (13%). Overall, 54% show epithelial marker reactivity. Molecular studies showed FOXO1 translocations (81%) with PCR demonstrating PAX3 in 72.7% tested. Patients presented with high stage (IV 24; III 26) and metastatic disease (lymph nodes n = 41; distant metastases n = 25) (IRSG grouping). Surgery (n = 16), radiation (n = 41) and chemotherapy (n = 45) yielded an overall survival of 36.1 months (mean; range 2.4-286); 18 alive without disease (mean 69.6 months); 7 alive with disease (mean 11.0 months); 1 dead without disease (63.7 months); and 26 dead with disease (mean 18.5 months). SNT ARMS frequently present in adults as a large, destructive midline mass of short symptom duration, with high stage disease. The alveolar to solid pattern of growth of cells with rhabdoid-plasmacytoid features suggests the diagnosis, but epithelial immunohistochemistry markers are present in 54% of cases, leading to misdiagnosis as carcinomas if muscle markers are not also performed. Overall survival of 36.1 months is achieved with multimodality therapy, but 64% have incurable disease (16.9 months). Mixed anatomic site (p = 0.02) was a significant adverse prognostic indicator, while stage (0.06) and tumor size >5 cm (0.06) approached marginal significance.

Pituitary Adenomas Presenting as Sinonasal or Nasopharyngeal Masses: A Case Series Illustrating Potential Diagnostic Pitfalls

We present a series of nonectopic pituitary adenomas presenting as polypoid sinonasal or nasopharyngeal masses. Thirteen cases diagnosed by biopsies from the nasal cavity, sinuses, or nasopharynx were identified from a series of 1288 surgical pituitary specimens. The patients included 5 men and 8 women ranging from 29 to 69 years of age. The presentations included nasal obstruction (4 cases), headaches (3), visual defects (2), recurrent nose bleeds (1), rhinorrhea (1), sepsis (1), fatigue (1), and hyperthyroidism (1). All patients had large tumors involving the sella and extending inferiorly to involve the sphenoid sinus in 10 cases, ethmoid in 8, nasopharynx in 3, nasal cavity in 6, maxillary and frontal sinuses in 1 case each. In 3 patients, the biopsy was from the nasopharynx, in 4 from the nasal cavity, in 4 from the sphenoid sinus, and in 2 from the ethmoid sinus. The correct diagnosis of pituitary adenoma was initially made in 10 cases. In 3 cases the initial diagnosis was incorrect; 2 tumors were classified as olfactory neuroblastoma, one of those was reclassified as neuroendocrine carcinoma, and 1 case was initially diagnosed as neuroendocrine carcinoma with aberrant adrenocorticotrophic hormone expression. Clinical follow-up (2 to 25 y) and treatment information was available in 10 cases. All 10 patients were alive, either free of disease (4 cases) or with disease (6 cases). In 2 cases, the wrong diagnoses led to incorrect treatment with significant morbidity. These cases illustrate that pituitary adenomas can invade nasopharynx and sinonasal cavities and when they do, they present a possible diagnostic pitfall with potentially serious consequences. We demonstrate the need to always consider this entity when encountering a nasopharyngeal or sinonasal tumor with neuroendocrine features.

Giant Prolactinoma Presenting As a Base of Skull Tumor With Nasopharyngeal Extension: A Potential Diagnostic Pitfall in Neuroendocrine Lesions of the Base of Skull

Pituitary adenomas presenting in uncommon anatomical locations are commonly misdiagnosed. Dramatic clinical presentation with hemorrhage and infarction, along with a lack of endocrine symptoms may further confound the diagnosis in some patients as illustrated in one of our two previously reported cases of non-small cell neuroendocrine carcinoma of the sinonasal tract and nasopharynx. This report presents the clinical progress of case number 2, which has a revised diagnosis of giant lactotroph pituitary adenoma. Common clinical, radiological and pathological pitfalls in diagnosis of neuroendocrine neoplasms of the sinonasal tract and base of skull are discussed.

LOW O6-METHYLGUANINE-DNA METHYTRANSFERASE (MGMT) AND PAN-CYTOKERATIN (PAN-CK) EXPRESSION VIA IMMUNOHISTOCHEMISTRY IN PITUITARY ADENOMAS

Introduction

Pituitary adenomas (PA) are the third most common intracranial tumors, with an incidence rate of 10-15%. More than half are invasive, infiltrating adjacent structures. The primary objective of this project was to determine whether MGMT expression is associated with the invasiveness of PA.

Material and Method

All patients who underwent surgical decompression consecutively between 2007-2012 were included. All data were obtained from the case records. Formalin-fixed paraffin-embedded (FFPE) tissue specimens were stained with hematoxylin and eosin (HE) and then examined via light microscope. Paraffin blocks that lacked necrosis and hemorrhage were chosen for histologic examination. In addition to an immunoprofile battery that consisted of Ki-67 and p53, MGMT, S-100 and Pan-CK were evaluated as well.

Results

The subjects included 25 women and 15 men. The mean age was 48.9 ± 14.5 years. Of these, 63% of cases involved the invasion of adjacent structures. Of the PA, 17 (42%) were non-functioning pituitary adenomas (NFPA). There was a statistically significant relationship between the invasiveness and Ki-67, p53, MGMT expression, and prolactinoma. Gonodotropinomas were mostly non-invasive. FPAs presented invasive features more frequently than NFPAs. Pan-CK was positive in GH-secreting adenomas but negative in FSH- and LH-secreting adenomas.

Conclusion

Ki-67 and p53 in lower expression level can be used for evaluating invasiveness but not for recurrence. MGMT expression can be a useful IHC indicator for invasiveness. However, Pan-CK cannot be used for invasiveness or aggressiveness.

Small round blue cell tumors of the sinonasal tract: a differential diagnosis approach

One of the most challenging diagnostic categories within tumors of the sinonasal tract is the small round blue cell tumors. Biopsies are usually small and limited, resulting in considerable diagnostic difficulty for practicing surgical pathologists. These tumors share several overlapping histologic and immunophenotypic findings while also showing considerable variation within and between cases. Specific tumor site of origin, imaging findings, and clinical findings must be combined with the histology and pertinent ancillary studies if the correct diagnosis is to be reached. Discrimination between neoplasms is critical as there are significant differences in therapy and overall outcome. It is important to have a well developed differential diagnosis for this category of tumors, where each of the diagnoses is considered, evaluated, and either confirmed or excluded from further consideration. In an undifferentiated tumor, showing a small round blue cell morphology, using the mnemonic 'MR SLEEP' helps to highlight tumors to consider: melanoma, mesenchymal chondrosarcoma, rhabdomyosarcoma, sinonasal undifferentiated carcinoma, squamous cell carcinoma (including NUT carcinoma), small cell osteosarcoma, lymphoma, esthesioneuroblastoma (olfactory neuroblastoma), Ewing sarcoma/primitive neuroectodermal tumor, pituitary adenoma, and plasmacytoma. A panel of pertinent immunohistochemistry studies, histochemistries and/or molecular tests should aid in reaching a diagnosis, especially when taking the pattern and intensity of reactions into consideration.

Sinonasal Small Round Blue Cell Tumors: An Immunohistochemical Approach

Although clinical history and morphologic appearance should be the initial considerations when evaluating small round blue cell tumors of the sinonasal tract, the final diagnosis often hinges on immunohistochemical findings. Unfortunately, interpretation of stains in these tumors is fraught with numerous pitfalls and limitations. This article presents an approach to sinonasal small round blue cell tumors based on four common immunohistochemical patterns: cytokeratin positivity, squamous marker positivity, neuroendocrine marker positivity, and cytokeratin negativity.

The Differential Diagnosis of Sinonasal/Nasopharyngeal Neuroendocrine/Neuroectodermally Derived Tumors

CONTEXT

The differential diagnosis of neuroendocrine neoplasms arising in the sinonasal tract is broad and includes lesions of epithelial, mesenchymal, and neuroectodermal origin.

OBJECTIVE

To review the differential diagnosis of sinonasal neuroendocrine and neuroectodermally derived tumors.

DATA SOURCES

The current literature was reviewed to provide updated information regarding the differential diagnosis and means for diagnosing neuroendocrine tumors including sinonasal neuroendocrine carcinoma, olfactory neuroblastoma, malignant melanoma, paraganglioma, pituitary adenoma, and Ewing family of tumors.

CONCLUSIONS

The differential diagnosis of neoplasms with neuroendocrine differentiation in the sinonasal tract is broad, and diagnosis often includes not only histologic review but also immunohistochemical or molecular analysis.

An Update on Sinonasal Round Cell Undifferentiated Tumors

The sinonasal cavities host a wide variety of undifferentiated malignancies with round cell morphology, including neoplasms of epithelial, mesenchymal, neuroectodermal, and hematolymphoid lineage. The differential diagnosis may be difficult, especially in small biopsy material, due to overlapping morphology, but their correct classification is clinically relevant. The aim of this review is to provide practical guidelines for the differential diagnosis of these malignancies, with emphasis on recently described entities and special reference to the role of ancillary techniques.

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.

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.