Mixed pituitary adenoma/pituitary neuroendocrine tumor-gangliocytoma: Immunohistochemical insights.

Mixed pituitary adenoma/PitNET-gangliocytomas (PA/PitNET-GC) have been reported in small series over the past 20 years; some had limited immunohistochemistry (IHC) data. We interrogated our experience over 20 years, focusing on patterns of the GC component and IHC results for anterior pituitary hormones, transcription factors, NFP, and CAM5.2. A search of cases from 2002 to 2023 yielded 20 cases: 7M:13F, ages 20-71 years; 17 macroadenomas, 1 microadenoma, 2 ectopic. GC was co-associated with 4 corticotroph, 2 densely granulated lactotroph, 5 mixed lactotroph-somatotroph, 1 immature PIT1-lineage tumor, and 8 sparsely granulated GH; the latter all had a minor lactotroph component. Patterns were: discrete nodular foci of GC (9/20), extensive GC differentiation often overshadowing the PA/PitNET (7/20), and intimate admixture of smaller bands of neuropil and individual metaplastic ganglion cells within PA/PitNET (4/20). NFP highlighted small cohesive regions of neuropil and identified greater axonal content, including individual axons within "pure" PA/PitNET areas, than appreciated on H&E. CAM5.2 IHC often revealed cells with neuronal morphologies to a greater extent than NFP and in different areas within the same tumor. These data suggest that the combined use of NFP and CAM5.2 IHC best reveals transition from PA to GC phenotype, with CAM5.2 positivity reflecting earlier stages of transformation.

Single-cell profiling of peripheral neuroblastic tumors identifies an aggressive transitional state that bridges an adrenergic-mesenchymal trajectory.

Peripheral neuroblastic tumors (PNTs) represent a spectrum of neural-crest-derived tumors, including neuroblastoma, ganglioneuroblastoma, and ganglioneuroma. Malignant cells in PNTs are theorized to interconvert between adrenergic/noradrenergic and mesenchymal/neural crest cell states. Here, single-cell RNA-sequencing analysis of 10 PNTs demonstrates extensive transcriptomic heterogeneity. Trajectory modeling suggests that malignant neuroblasts move between adrenergic and mesenchymal cell states via an intermediate state that we term "transitional." Transitional cells express programs linked to a sympathoadrenal development and aggressive tumor phenotypes such as rapid proliferation and tumor dissemination. Among primary bulk tumor patient cohorts, high expression of the transitional gene signature is predictive of poor prognosis compared with adrenergic and mesenchymal expression patterns. High transitional gene expression in neuroblastoma cell lines identifies a similar transitional H3K27-acetylation super-enhancer landscape. Collectively, our study supports the concept that PNTs have phenotypic plasticity and uncovers potential biomarkers and therapeutic targets.

Genetic and Histopathological Heterogeneity of Neuroblastoma and Precision Therapeutic Approaches for Extremely Unfavorable Histology Subgroups.

Peripheral neuroblastic tumors (neuroblastoma, ganglioneuroblastoma and ganglioneuroma) are heterogeneous and their diverse and wide range of clinical behaviors (spontaneous regression, tumor maturation and aggressive progression) are closely associated with genetic/molecular properties of the individual tumors. The International Neuroblastoma Pathology Classification, a biologically relevant and prognostically significant morphology classification distinguishing the favorable histology (FH) and unfavorable histology (UH) groups in this disease, predicts survival probabilities of the patients with the highest hazard ratio. The recent advance of neuroblastoma research with precision medicine approaches demonstrates that tumors in the UH group are also heterogeneous and four distinct subgroups-MYC, TERT, ALT and null-are identified. Among them, the first three subgroups are collectively named extremely unfavorable histology (EUH) tumors because of their highly aggressive clinical behavior. As indicated by their names, these EUH tumors are individually defined by their potential targets detected molecularly and immunohistochemically, such as MYC-family protein overexpression, TERT overexpression and ATRX (or DAXX) loss. In the latter half on this paper, the current status of therapeutic targeting of these EUH tumors is discussed for the future development of effective treatments of the patients.

An urban legend: Malignant transformation caused by radiotherapy in patients with presacral ganglioneuroma. The necessity and first-time administration of radiotherapy. Case report and literature review.

Ganglioneuromas (GNs) are well-differentiated, rare benign tumors of neural crest origin and are, for the most part, considered to be the benign equivalent of neuroblastomas. There are very few cases of GN reported to be at presacral location in the literature. The standard form of treatment is the total surgical excision. However, total resection of GN is not always possible depending on the neuron, from which it originates, and its localization. Moreover, adjuvant radiotherapy (RT) or chemotherapy is not recommended even though patients are still symptomatic after subtotal resection. This view is based on the urban legend that it undergoes a malignant transformation although it is a benign tumor. Moreover, there are no data indicating that the GN cases reported in the literature have undergone RT. Therefore, articles about the suspicion that GN may undergo spontaneous or malignant transformation after RT are absolutely controversial. Based on our case, we present here, we believe that we will explain the valid necessity of application of RT that we administered for the first time and that with the clarification of this controversial topic, a significant gap will be closed in the literature.

RET overactivation leads to concurrent Hirschsprung disease and intestinal ganglioneuromas.

Appropriately balanced RET signaling is of crucial importance during embryonic neural crest cell migration, proliferation and differentiation. RET deficiency, for example, leads to intestinal aganglionosis (Hirschsprung disease), whereas overactive RET can lead to multiple endocrine neoplasia (MEN) syndromes. Some RET mutations are associated with both intestinal aganglionosis and MEN-associated tumors. This seemingly paradoxical occurrence has led to speculation of a 'Janus mutation' in RET that causes overactivation or impairment of RET activity depending on the cellular context. Using an intestinal catenary culture system to test the effects of GDNF-mediated RET activation, we demonstrate the concurrent development of distal colonic aganglionosis and intestinal ganglioneuromas. Interestingly, the tumors induced by GDNF stimulation contain enteric neuronal progenitors capable of reconstituting an enteric nervous system when transplanted into a normal developmental environment. These results suggest that a Janus mutation may not be required to explain co-existing Hirschsprung disease and MEN-associated tumors, but rather that RET overstimulation alone is enough to cause both phenotypes. The results also suggest that reprogramming tumor cells toward non-pathological fates may represent a possible therapeutic avenue for MEN-associated neoplasms.

Ganglioneuromas are driven by activated AKT and can be therapeutically targeted with mTOR inhibitors.

Peripheral sympathetic nervous system tumors are the most common extracranial solid tumors of childhood and include neuroblastoma, ganglioneuroblastoma, and ganglioneuroma. Surgery is the only effective therapy for ganglioneuroma, which may be challenging due to the location of the tumor and involvement of surrounding structures. Thus, there is a need for well-tolerated presurgical therapies that could reduce the size and extent of ganglioneuroma and therefore limit surgical morbidity. Here, we found that an AKT-mTOR-S6 pathway was active in human ganglioneuroma but not neuroblastoma samples. Zebrafish transgenic for constitutively activated myr-Akt2 in the sympathetic nervous system were found to develop ganglioneuroma without progression to neuroblastoma. Inhibition of the downstream AKT target, mTOR, in zebrafish with ganglioneuroma effectively reduced the tumor burden. Our results implicate activated AKT as a tumorigenic driver in ganglioneuroma. We propose a clinical trial of mTOR inhibitors as a means to shrink large ganglioneuromas before resection in order to reduce surgical morbidity.

Frequency of ALK and GD2 Expression in Neuroblastoma.

Background: The aim of this study was to elucidate the significance of immunohistochemical staining patterns of ALK and GD2 in peripheral neuroblastic tumors with different stages and favorable/unfavorable features. Materials and methods: 32 neuroblastomas, 7 ganglioneuroblastomas, and 1 ganglioneuroma cases were immunohistochemically stained with ALK and GD2, and the expressions were graded and correlated with differentiation, size, and favorable/unfavorable histology. Results: There was no statistically significant correlation between ALK immunopositivity and tumor differentiation or stage. Although there was no statistically significant correlation between GD2 immunopositivity and stage, the intensity and prevalence of GD2 immunostaining were statistically significantly higher in the well differentiated group and in tumors which were smaller than 10 cm. Conclusion: GD2 immunostaining levels correlated with tumor differentiation and size. ALK immunostaining was not related to tumor differentiation or stage.

Clinicopathological and molecular analysis of multinodular and vacuolating neuronal tumors of the cerebrum.

Multinodular and vacuolating neuronal tumor (MVNT) of the cerebrum is a recently recognized rare neuronal tumor, and its pathogenesis is unclear. We analyzed 7 cases of histologically typical MVNT: 6 were adults (mean age, 43.0 years [range, 23-56 years]) and 1 was a child (age, 10 years). The most common symptoms were seizures (n = 4) and headache (n = 2). The tumors were supratentorial (temporal, 5; frontal lobes, 2) in origin as reported. Vacuolated tumor cells were robustly positive for α-INA and Olig2 and at least partly positive for synaptophysin and MAP2, but negative for Neu-N, nestin and CD34. GFAP and vimentin were expressed in reactive astrocytes but not in tumor cells. Negative results were obtained for p53, IDH-1, BRAFV600E, H3 K27M, EGFR, Lin28A, and L1CAM. ATRX, BRG1, INI-1, and TMHH were retained. The Ki-67 labeling index was very low (<1%), and pHH3 revealed no mitotic figure. Ultrastructural features of tumor cells were comparable with those of immature neuronal cells, with several intracytoplasmic myelin-like autophagosomes and pericellular vacuolization. No IDH1/IDH2 and BRAFV600E mutations were found upon direct sequencing. Whole-exome sequencing revealed FGFR2-ZMYND11 gene fusion in 1 case. After gross total resection, all patients were alive without seizures. There was no tumor recurrence during an average period of 68 months (range, 23-101 months). The analysis of 7 typical cases of MVNT suggested that these lesions may be clonal tumors because FGFR2-ZMYND11 fusion was found (1 case).

The deubiquitinating enzyme UCHL1 is a favorable prognostic marker in neuroblastoma as it promotes neuronal differentiation.

BACKGROUND: Neuroblastoma (NB) is the most common pediatric solid tumor that originates from neural crest-derived sympathoadrenal precursor cells that are committed to development of sympathetic nervous system. The well differentiated histological phenotype of NB tumor cells has been reportedly associated with favorable patient outcome. Retinoic acid (RA) can effectively induce NB cell differentiation, thereby being used in the clinic as a treatment agent for inducing the differentiation of high-risk NB. However, the underlying molecular mechanisms of regulating differentiation remain elusive. METHODS: The correlation between clinical characteristics, survival and the deubiquitinating enzyme ubiquitin C-terminal hydrolase 1 (UCHL1) expression were assessed using a neuroblastic tumor tissue microarray, and then validated in three independent patient datasets. The different expression of UCHL1 in ganglioneuroblastoma, ganglioneuroma and NB was detected by immunohistochemistry, mass spectra and immunoblotting analysis, and the correlation between UCHL1 expression and the differentiated histology was analyzed, which was also validated in three independent patient datasets. Furthermore, the roles of UCHL1 in NB cell differentiation and proliferation and the underlying mechanisms were studied by using short hairpin RNA and its inhibitor LDN57444 in vitro. RESULTS: Based on our neuroblastic tumor tissue microarrays and three independent validation datasets (Oberthuer, Versteeg and Seeger), we identified that UCHL1 served as a prognostic marker for better clinical outcome in NB. We further demonstrated that high UCHL1 expression was associated with NB differentiation, indicated by higher UCHL1 expression in ganglioneuroblastomas/ganglioneuromas and well-differentiated NB than poorly differentiated NB, and the positive correlation between UCHL1 and differentiation markers. As expected, inhibiting UCHL1 by knockdown or LDN57444 could significantly inhibit RA-induced neural differentiation of NB tumor cells, characterized by decreased neurite outgrowth and neural differentiation markers. This effect of UCHL1 was associated with positively regulating RA-induced AKT and ERK1/2 signaling activation. What's more, knockdown of UCHL1 conferred resistance to RA-induced growth arrest. CONCLUSION: Our findings identify a pivotal role of UCHL1 in NB cell differentiation and as a prognostic marker for survival in patients with NB, potentially providing a novel therapeutic target for NB.

Discrimination of histopathologic types of childhood peripheral neuroblastic tumors based on clinical and biological factors.

The aim of this study was to discriminate the children malignant peripheral neuroblastic tumors (PNTs) from those with benign histotype ganglioneuroma (GN) based on clinical and biological characteristics in all PNTs. Four hundred and seventy-six patients were included in this study, containing 345 patients for model development and 131 patients for external validation. Multivariate logistic regression analysis was conducted to select potentially useful characteristics for discrimination of histopathology. External validation was performed for model evaluation. Compared with the main characteristics of GN (85/345, 24.6%), those of malignant PNTs (260/345, 75.4%) showed significant differences. Multivariate analysis was performed to further find the characteristics linked to histopathology. The results indicated that for the patients younger than 49 months, the primary site of adrenal and thoracic, the level of serum neuron-specific enolase (NSE) > 33 ng/mL, and tumor encasing blood vessels were the extremely important discrimination factors of malignant PNTs. The area under the receiver-operating-characteristic of the discrimination model was 0.96. The accuracy rate, sensitivity and specificity were 93.4%, 96.3% and 83.8%, respectively. Meanwhile, the accuracy rate of the external validation from the 131 patients was 97.0%. Overall, histopathologic type of childhood malignant PNTs can be discriminated based on age, primary site, NSE level and the relationship between primary tumor and blood vessels.

Verner-Morrison syndrome. Literature review.

Chronic diarrhea in infants is a common condition for addressability to pediatric gastroenterologists. The causes are multiple and the delay in reaching the final diagnosis can lead to complications in the general condition of the child. The purpose of this review is to present the bio-clinical and histogenetic particularities of a rare clinical entity, characterized by tumoral causes of chronic diarrhea. VIPomas are neuroendocrine tumors that autonomously secrete vasoactive intestinal peptide (VIP). Watery diarrhea, hypokalemia and achlorhydria (WDHA) syndrome caused by VIP-producing tumors only rarely occurs in adult patients with non-pancreatic disease. In pediatric patients, it is extremely rare for a VIPoma to originate in the pancreas; instead, WDHA syndrome is usually associated with VIP-secreting neurogenic tumors involving the retroperitoneum or mediastinum. The majority of VIP secreting tumors in pediatric patients are represented by ganglioneuroblastomas or ganglioneuromas originating in the adrenal medulla or sympathetic neural crest. This syndrome of watery diarrhea associated with hypokalemia and achlorhydria was first described by Verner and Morrison, in 1958, and has been assumed to be due to hypersecretion of VIP. In children, as well as in adult patients, the most likely explanation for persistent secretory diarrhea may be an occult VIPoma. In conclusion, the physicians should be aware that there are some rare tumoral causes of chronic diarrhea, often under-diagnosed. If the diagnosis is not considered, extensive gastrointestinal investigations will be undertaken, delaying the diagnosis and avoidable morbidity will occur.

Characteristics of ganglion cells in pituitary gangliocytomas.

The occurrence of ganglion cells in the sella turcica, in association or not with a pituitary adenoma, has been rarely reported. Various names have been employed for this rare entity, gangliocytoma being frequently used and recommended by WHO classification. Expression of cytokeratin in these ganglion cells has been previously occasionally reported, a very intriguing observation raising questions on the possible nature and derivation of these cells. We describe the pathological findings in three cases of growth hormone-producing adenomas, all sparsely granulated, showing the presence of a ganglion cell population admixed with an adenomatous component. A review of the literature is also provided.

Cyclin D1 in pediatric neuroblastic tumors: A microarray analysis.

Neuroblastoma is the most common extracranial solid childhood tumor, which is believed to originate from primitive neuroblasts giving rise to the sympathetic nervous system. It was previously shown that cyclin D1 (CCDN1) in pediatric neuroblastic tumors (neuroblastoma, ganglioneuroblastoma, and ganglioneuroma) recapitulates its expression during the development of peripheral sympathetic nervous system (PSNS). In the present study, we performed a microarray analysis in order to evaluate the expression of cyclin D1 in neuroblastoma as compared to ganglioneuroma and ganglioneuroblastoma. We first confirmed that comparable levels of cyclin D1 are present in neuroblastoma and fetal neuroblasts. In addition, we observed that neuroblastoma is associated to significantly higher levels of cyclin D1 as compared to both ganglioneuroma and ganglioneuroblastoma. No differences are instead observable between ganglioneuroblastoma and ganglioneuroma. Finally, bioinformatic analysis of cyclin D1-functionally related genes, identified cyclin D2 as an additional marker/etiopathogenic factor in the development of neuroblastoma.

Diffuse Ganglioneuromatosis of the Colon Presenting as a Large Subepithelial Tumor in Adults: Report of Two Cases.

Colonic diffuse ganglioneuromatosis is a benign neoplastic condition characterized by disseminated, intramural, or transmural proliferation of neural elements involving the enteric plexuses, sometimes associated with von Recklinghausen's disease and other multiple tumor syndromes. Colonic diffuse ganglioneuromatosis is usually large, ranging from 1 to 17 cm, and thus can distort the surrounding tissue architecture as well as infiltrate the adjacent bowel wall. However, colonic diffuse ganglioneuromatosis is an exceptional finding in adults and only individual cases are reported in the literature. Herein, we report two unusual cases of adult patients with colonic diffuse transmural ganglioneuromatosis presenting as a large subepithelial tumor.

Composite pheochromocytoma of the adrenal gland: a case series.

BACKGROUND: Composite pheochromocytoma is a rare pathological condition characterized by elements of both pheochromocytoma and neurogenic tumors. However, detailed clinical outcomes of this tumor have not been fully shown. From 2007 to 2013, we experienced three cases of adrenal composite pheochromocytoma. In this report, we investigate the clinicopathological features of these three cases of composite pheochromocytoma and compare them with previously reported cases. CASE PRESENTATIONS: Cases 1 and 2 were a 29-year-old Japanese woman and a 59-year-old Japanese man, respectively. They underwent laparoscopic left adrenalectomy, and pathological examination revealed composite pheochromocytoma-ganglioneuroma. Case 3 was a 53-year-old Japanese man who had been receiving hemodialysis for 17 years. He underwent laparoscopic right adrenalectomy, and pathological examination revealed composite pheochromocytoma-ganglioneuroblastoma. Although the Ki67-positive rates varied from 1.0 to 6.2% among the three cases, no clinical recurrences occurred. Despite the relatively high rate of Ki67 positivity, complete tumor resection resulted in favorable clinical outcomes. CONCLUSION: We experienced three cases of adrenal composite pheochromocytoma. Although the clinical findings and treatment outcomes of composite pheochromocytoma were similar to those of ordinary pheochromocytoma, further studies of the biological behavior and genetic profiles of composite pheochromocytoma are necessary to achieve a better understanding of this tumor.

Primary intraosseous ganglioneuromatous paraganglioma of the sacrum with immunopositivity for cytokeratin.

BACKGROUND: Paragangliomas are derived from neurosecretory cells believed to be of neural crest origin. A spinal location of paraganglioma is rare and usually presents as an intradural mass. PATIENT AND METHODS: A primary intraosseous paraganglioma of sacrum is extremely unusual, and only 6 cases were reported. In this study, we report a rare case of a 44-year-old man with the complaint of low back pain and lower extremity weakness. Imaging workup, including computerized tomography (CT), and magnetic resonance imaging (MRI) presented an intraosseous sacral lesion with invasion of sacrum in the S1-S3 vertebrae, and extension to L4-L5 spinal canal. The patient underwent subtotal tumor resection, followed by radiation therapy. RESULTS: The morphological and immunohistochemical studies revealed a composite tumor of paraganglioma and ganglioneuroma components, with immunopositivity for cytokeratin. CONCLUSIONS: To the best of our knowledge, this is the first report in the literature demonstrating an intraosseous sacral paraganglioma with these 2 pathological features.

Infrasellar pituitary gangliocytoma causing Cushing's syndrome.

INTRODUCTION: Pituitary gangliocytomas are uncommon neuronal tumours that may present with endocrine disorders, the most frequent being acromegaly caused by growth hormone hypersecretion. Cushing's syndrome is very rarely seen with gangliocytomas. MATERIAL AND METHODS: We report the unique case of a 62 year-old woman whose clinical picture and endocrine testing clearly demonstrated adrenocorticotropin (ACTH)-dependent Cushing's syndrome. Pituitary magnetic resonance imaging showed a 12-mm homogeneous, infra- and retrosellar mass first diagnosed as pituitary macroadenoma. Transsphenoidal surgery was performed and allowed complete resection of the tumour with sparing of normal anterior pituitary. Very low postoperative serum cortisol and ACTH levels were observed in the early postoperative period and the patient is still in remission 18 months after surgery, thus demonstrating that the resected lesion was entirely responsible for the clinical picture. RESULTS: Histological and immunocytochemical analyses demonstrated a benign tumour composed of mature neuronal cells suggestive of a gangliocytoma, expressing both ACTH and corticotropin-releasing hormone (CRH). The tumour was surrounded by a rim of pituitary tissue containing ACTH-producing endocrine cells. Careful analysis of the resected lesion did not reveal any pituitary microadenoma. We search literature for similar cases and retraced only nine cases of gangliocytomas associated with Cushing's syndrome. In most of them, the tumour was combined with either pituitary corticotroph adenoma or hyperplasia. CONCLUSIONS: Our case represents a unique case of an infrasellar pituitary gangliocytoma which was able to cause Cushing's syndrome by both direct ACTH production and CRH-induced stimulation of neighbour normal corticotroph cells.

Pituitary adenoma with gangliocytic component: report of 5 cases with focus on immunoprofile of gangliocytic component.

INTRODUCTION: Pituitary adenomas with gangliocytic component are rare tumors of the sellar region that are composed of pituitary adenoma cells and a ganglion cell component. Their histogenesis and hence nosology is not yet resolved because of the small number of cases reported and lack of large series in the literature. METHODS: Herein we report five cases of pituitary adenoma with gangliocytic component to add knowledge to this rare neoplasm. RESULTS: Three cases are functional mammosomatotroph adenomas, one case is functional sparsely granulated somatotroph adenoma and the other is functional corticotroph adenoma. Gangliocytic component showed immunohistochemical expression of hormones in three cases. The ganglion cells were prolactin immunoreactive in case 1, GH and TSH immunoreactive in case 5 and showed expression of prolactin, TSH, ACTH and FSH in case 4. Three cases had undergone more than one surgery of which two had gangliocytic cells only in the recurrent tumors whereas the third case showed gangliocytic cells only in the initial tumor. DISCUSSION: The cases are discussed with clinical and histological features and a brief review of the literature considering the histogenesis is included.

Neurogenic polyps of the gastrointestinal tract: a clinicopathologic review with emphasis on differential diagnosis and syndromic associations.

Primary neurogenic gastrointestinal polyps are encountered relatively frequently in routine pathology practice. They encompass a variety of neoplastic entities with clinical, morphologic, and molecular features that reflect the diversity of neural elements within the gastrointestinal system. Although most are benign and encountered incidentally, accurate diagnosis may have important clinical implications because of the associations of certain neurogenic polyps with familial syndromes or other conditions. We review the pathology of these polyps with an emphasis on the diagnostic challenges that they pose and on newly described subtypes.