Oncocytic lesions of the neuroendocrine system

Adrenal Oncocytic Pheochromocytoma: Insights From a Challenging Diagnostic Journey

Pheochromocytomas are rare adrenal medulla tumors originating from chromaffin cells, accounting for 10% of primary adrenal neoplasms. Oncocytic variants of pheochromocytomas are rare and have been reported in only 150 cases. This report describes the case of a 60-year-old female who arrived with a non-functional adrenal tumor. This case report emphasizes the importance of a comprehensive histological and immunohistochemical study for diagnosing this rare diagnostic entity and its potential diagnostic pitfalls.

Cytopathology of solid pancreatic neoplasms: An algorithmic approach to diagnosis

The classification and management of solid pancreatic neoplasms has expanded significantly in recent years because of advances in immunohistochemical markers, molecular diagnostics, and therapeutics. Solid pancreatic masses are subdivided into 1) ill-defined, scirrhous, and stroma-rich (ductal adenocarcinoma) and 2) well circumscribed, cellular, and stroma-poor (including neuroendocrine neoplasms, acinar cell carcinoma, pancreatoblastoma, and solid-pseudopapillary neoplasm). Definitive diagnosis, particularly of stroma-poor, circumscribed tumors, requires the incorporation of radiologic and cytologic findings, along with the judicious use of (broad, but limited) immunohistochemical panels (pancytokeratin and neuroendocrine [synaptophysin], acinar [trypsin], and solid-pseudopapillary neoplasm [β-catenin] markers), along with unstained slides. Depending on the initial results, immunohistochemical panels should be expanded to include more confirmatory (acinar and neuroendocrine) markers. This ensures that adequate material is available for definitive diagnosis/subclassification and, in some cases, grading, and/or molecular studies, particularly of grade 3 neuroendocrine neoplasms and mixed-lineage tumors. The objective of this review is to expand the understanding of the cytomorphology of solid pancreatic neoplasms using an integrated, multidisciplinary approach in their diagnosis. Knowledge and understanding of recent updates in the classification of solid pancreatic neoplasms ensures that cytopathologists appropriately triage specimens, judiciously use and interpret ancillary studies, and incorporate these results in reporting.

Challenges in Cytology Specimens With Hürthle Cells

In fine-needle aspirations (FNA) of thyroid, Hürthle cells can be found in a broad spectrum of lesions, ranging from non-neoplastic conditions to aggressive malignant tumors. Recognize them morphologically, frequently represents a challenging for an adequately diagnosis and are associated with a significant interobserver variability. Although the limitations of the morphologic diagnosis still exist, the interpretation of the context where the cells appear and the recent advances in the molecular knowledge of Hürthle cells tumors are contributing for a more precise diagnosis. This review aims to describe the cytology aspects of all Hürthle cells neoplastic and non-neoplastic thyroid lesions, focusing on the differential diagnosis and reporting according to The Bethesda System for Reporting Thyroid Cytology (TBSRTC). New entities according to the latest World Health Organization (WHO) classification are included, as well as an update of the current molecular data.

American Association of Clinical Endocrinology Disease State Clinical Review on the Evaluation and Management of Adrenocortical Carcinoma in an Adult: a Practical Approach

OBJECTIVE

The aim of this Disease State Clinical Review is to provide a practical approach to patients with newly diagnosed adrenocortical carcinoma, as well as to follow-up and management of patients with persistent or recurrent disease.

METHODS

This is a case-based clinical review. The provided recommendations are based on evidence available from randomized prospective clinical studies, cohort studies, cross-sectional and case-based studies, and expert opinions.

RESULTS

Adrenocortical carcinoma is a rare malignancy, often with poor outcomes. For any patient with an adrenal mass suspicious for adrenocortical carcinoma, the approach should include prompt evaluation with detailed history and physical exam, imaging, and biochemical adrenal hormone assessment. In addition to adrenal-focused imaging, patients should be evaluated with chest-abdomen-pelvis cross-sectional imaging to define the initial therapy plan. Patients with potentially resectable disease limited to the adrenal gland should undergo en bloc open surgery by an expert surgeon. For patients presenting with advanced or recurrent disease, a multidisciplinary approach considering curative repeat surgery, local control with surgery, radiation therapy or radiofrequency ablation, or systemic therapy with mitotane and/or cytotoxic chemotherapy is recommended.

CONCLUSION

As most health care providers will rarely encounter a patient with adrenocortical carcinoma, we recommend that patients with suspected adrenocortical carcinoma be evaluated by an expert multidisciplinary team which includes clinicians with expertise in adrenal tumors, including endocrinologists, oncologists, surgeons, radiation oncologists, pathologists, geneticists, and radiologists. We recommend that patients in remote locations be followed by the local health care provider in collaboration with a multidisciplinary team at an expert adrenal tumor program.

ABBREVIATIONS

ACC = adrenocortical carcinoma; ACTH = adrenocorticotropic hormone; BRACC = borderline resectable adrenocortical carcinoma; CT = computed tomography; DHEAS = dehydroepiandrosterone sulfate; EDP = etoposide, doxorubicin, cisplatin; FDG = ¹⁸F-fluorodeoxyglucose; FNA = fine-needle aspiration; HU = Hounsfield units; IVC = inferior vena cava; LFS = Li-Fraumeni syndrome; MEN1 = multiple endocrine neoplasia type 1; MRI = magnetic resonance imaging; OAC = oncocytic adrenocortical carcinoma; PC = palliative care; PET = positron emission tomography.

Morphologic Variants of Pancreatic Neuroendocrine Tumors: Clinicopathologic Analysis and Prognostic Stratification

Better prognostication/stratification of pancreatic neuroendocrine tumors (PanNETs) is needed. In this detailed morpheomic study of 163 resected PanNETs, 11 unusual variants, some of which were not previously recognized, and others scarcely documented in the literature, were identified, and their pathologic characteristics were further analyzed. By behavior and clinicopathologic associations, these variants could be grouped into three prognostically different categories. I. More aggressive (20%). Included in this group were the variants that in average showed higher grade and stage and adverse outcome including oncocytic, plasmacytoid, lipid-rich and previously unrecognized hepatoid variants, which often had a more diffuse/broad-band growth pattern, with some also displaying discohesiveness. They were characterized by abundant cytoplasm and often had prominent nucleoli (as seen in metabolically active cells), thus the provisional name "metabolic cell phenotype." Because of their diversion from classical neuroendocrine cytomorphology, these variants created challenges on original diagnostic workup, particularly hepatoid examples, which revealed Arginase 1/Hep Par-1 expression in 50%. II. Less aggressive (10%). These cases either showed signs of maturation, including nested growth, paraganglioid pattern (which was previously unrecognized), and organoid PanNETs such as "ductulo-insular" growth, or showed symplastic/degenerative changes, and despite their paradoxically disconcerting histology, were more benevolent in behavior. III. Undetermined. There were other variants including mammary tubulolobular-like, pseudoglandular, peliotic, and sclerotic PanNETs, which although diagnostically challenging, their biologic significance could not be determined because of rarity or heterogeneous characteristics. Prognostic associations: Features that were significantly different in the more aggressive group than the less aggressive group were median size (5.0 vs 1.6 cm, p < 0.001), percentage of pT3+T4 cases (72% vs 12%, p < 0.001), Ki67 index (5.3% vs 2.3%, p = 0.001), % G2 and G3 cases (77% vs 27%, p < 0.001), and rate of lymph node and distant metastasis (96% vs 27%, p < 0.001). In stepwise logistic regression model using the 3 established prognosticators of T stage, size, and grade along with morphology, only aggressive-morphology (metabolic cell phenotype) was found to be associated with metastatic behavior with an odds ratio of 5.9 with 95% confidence interval (C.I.) 1.688 to 22.945 and p value 0.007. In conclusion, PanNETs display various morphologic patterns that are not only challenging and important diagnostically but appear to have biologic significance. Tumors with more diffuse growth of cells with nucleoli and abundant cytoplasm and/or discohesion (oncocytic, hepatoid, lipid-rich, plasmacytoid PanNETs), provisionally termed "metabolic cell phenotype," show aggressive characteristics and are an independent determinant of adverse outcome and thus may require closer post-surgical follow-up, whereas variants with more degenerative or mature features (ductuloinsular, pleomorphic, paraganglioma-like) appear to be more benevolent despite their more atypical and worrisome morphology.

What is hiding behind S100 protein and SOX10 positive oncocytomas? Oncocytic pleomorphic adenoma and myoepithelioma with novel gene fusions in a subset of cases

Oncocytomas (OCs) in salivary glands are rare benign tumors composed of mitochondria-rich epithelial cells (oncocytes), mostly localized in the parotid gland. The treatment of choice is simple excision. Extensive oncocytic metaplasia of pleomorphic adenoma (PA) and myoepithelioma (ME) can be diagnostically challenging and may camouflage the correct diagnosis. These tumors should be treated more carefully compared with OC, given the risk of frequent recurrences and the possibility of malignant transformation. We have investigated 89 oncocytic lesions from our files, including OC (n = 74) and metaplastic oncocytic variant of PA/ME (n = 15). All OCs were stained for S100 protein and SOX10. The tumors with immunohistochemical expression of one or both markers were tested by next-generation sequencing (NGS). The NGS results were confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and/or fluorescence in situ hybridization (FISH). Ten cases originally diagnosed as OC, and 1 low-grade uncertain oncocytic tumor (11/74) revealed nuclear-cytoplasmic and/or nuclear positivity for S100 protein and/or SOX10, respectively. Fusion transcripts CHCHD7-PLAG1 and GEM-PLAG1 were found in 2 cases (1 fusion in each), and these were confirmed by RT-PCR and PLAG1 break-apart FISH probe, respectively. Another 5 cases were positive for PLAG1 rearrangement by FISH. In the control group of 15 oncocytic PA/ME, 4/15 tested tumors harbored gene fusions including NFT3-PLAG1, CHCHD7-PLAG1, FBXO32-PLAG1, and C1orf116-PLAG1 (1 fusion in each case) as detected by NGS. Two fusions were confirmed by RT-PCR, 1 case by FISH, and 1 case was not analyzable by FISH. We additionally tested 24 OCs negative for S100 protein and SOX10 by immunohistochemistry (IHC) and by FISH for rearrangement of PLAG1 gene, but none of them were positive. SOX10 and/or S100 protein immunopositivity in conjunction with rearrangement of the PLAG1 gene assisted in reclassification of a subset of oncocytomas as oncocytic variants of PA and ME. Therefore, we recommend to include S100 protein and SOX10 IHC when diagnosing tumors with predominantly oncocytoma-like differentiation. In addition, by NGS, 3 new gene fusions were detected in oncocytic ME, including NTF3-PLAG1, FBXO32-PLAG1, and GEM-PLAG1, and a new fusion C1orf116-PLAG1 was detected in oncocytic PA.

Genetics of Pituitary Tumours

Pituitary tumours are relatively common in the general population. Most often they occur sporadically, with somatic mutations accounting for a significant minority of somatotroph and corticotroph adenomas. Pituitary tumours can also develop secondary to germline mutations as part of a complex syndrome or as familial isolated pituitary adenomas. Tumours occurring in a familial setting may present at a younger age and can behave more aggressively with resistance to treatment. This chapter will focus on the genetics and molecular pathogenesis of pituitary tumours.

Oncocytic subtypes of adrenal cortical carcinoma: Aggressive in appearance yet more indolent in behavior?

BACKGROUND

Adrenal cortical carcinoma is an aggressive malignancy and typically heralds a poor prognosis. The oncocytic subtype of this neoplasm is rare but may be associated with more favorable outcomes.

METHODS

The Provincial Cancer Registry was searched for cases of adrenal cortical carcinoma between 1992 and 2017. Comprehensive chart reviews were performed and data gathered related to presentation, treatment, and outcomes.

RESULTS

In the study, 82 patients with adrenal cortical carcinoma were identified. Complete data were available for 67 patients (82%). In the 41 patients who underwent resection, 9 (22%) had oncocytic subtypes. When compared with the total group of adrenal cortical carcinomas, the oncocytic subtypes were larger at presentation (19.8 cm vs 11.0 cm), more commonly symptomatic and hormonally active, and despite larger tumor size, were often early stage I and II. Recurrent disease was observed in 3 out of 9 oncocytic subtype (vs 23 out of 32 adrenal cortical carcinoma), with greater median time to recurrence (17.5 vs 8 months). Univariate analysis suggested that age, T-stage, M-stage, and overall stage were associated with survival. There was a trend toward improved overall survival for patients with oncocytic subtype on Kaplan-Meier and multivariate analysis.

CONCLUSION

Despite our small numbers of patients with oncocytic subtype, our data suggest that oncocytic subtype are typically larger at presentation but more often early stage and recur less frequently than adrenocortical carcinomas. Modifications to treatment and surveillance strategies may be appropriate in this subtype.

Clinical and Pathological Aspects of Silent Pituitary Adenomas

CONTEXT

Silent pituitary adenomas are anterior pituitary tumors with hormone synthesis but without signs or symptoms of hormone hypersecretion. They have been increasingly recognized and represent challenging diagnostic issues.

EVIDENCE ACQUISITION

A comprehensive literature search was performed using MEDLINE and EMBASE databases from January 2000 to March 2018 with the following key words: (i) pituitary adenoma/tumor and nonfunctioning; or (ii) pituitary adenoma/tumor and silent. All titles and abstracts of the retrieved articles were reviewed, and recent advances in the field of silent pituitary adenomas were summarized.

EVIDENCE SYNTHESIS

The clinical and biochemical picture of pituitary adenomas reflects a continuum between functional and silent adenomas. Although some adenomas are truly silent, others will show some evidence of biochemical hypersecretion or could have subtle clinical signs and, therefore, can be referred to as clinically silent or "whispering" adenomas. Silent tumors seem to be more aggressive than their secreting counterparts, with a greater recurrence rate. Transcription factors for pituitary cell lineages have been introduced into the 2017 World Health Organization guidelines: steroidogenic factor 1 staining for gonadotroph lineage; PIT1 (pituitary-specific positive transcription factor 1) for growth hormone, prolactin, and TSH lineage, and TPIT for the corticotroph lineage. Prospective studies applying these criteria will establish the value of the new classification.

CONCLUSIONS

A concise review of the clinical and pathological aspects of silent pituitary adenomas was conducted in view of the new World Health Organization classification of pituitary adenomas. New classifications, novel prognostics markers, and emerging imaging and therapeutic approaches need to be evaluated to better serve this unique group of patients.

Adrenocortical oncocytic neoplasm: A systematic review

BACKGROUND

Adrenocortical oncocytic neoplasms are rare tumors, generally regarded as benign and hormonally nonfunctional. We performed a systematic review to update the literature on adrenocortical oncocytic neoplasms by reviewing patient and tumor characteristics, as well as management trends, because the literature is composed of predominately single-case reports.

METHODS

A systematic search was performed in PubMed, Embase, and Cochrane Library through June 2017. Malignant potential was determined by applying the Lin-Weiss-Bisceglia criteria to cases.

RESULTS

Included for analysis were 84 citations describing 140 adrenocortical oncocytic neoplasms, including our own case. These were diagnosed predominantly in females (66%), on the left side (64%), and were nonfunctional (66%). Average age at diagnosis was 44 years (2.5-77), and median tumor size was 80 mm (16-285). A total of 35% of adrenocortical oncocytic neoplasms were benign, 41% borderline, and 24% malignant. Male patients were more likely to have a malignant tumor compared with females (36% versus 18%, P = .035). The 5-year overall survival for benign adrenocortical oncocytic neoplasms was 100%, borderline 88%, and malignant 47%. Hormonal function did not discriminate malignant from benign lesions. Adrenocortical oncocytic neoplasms that stained positive for synaptophysin (50%, P < .001) and negative for vimentin (62%, P = .009) are more often benign.

CONCLUSION

We found that the majority of adrenocortical oncocytic neoplasms (65%) were either malignant or had malignant potential, contrary to the previous literature. The Lin-Weiss-Bisceglia criteria are useful in identifying those patients for whom closer surveillance is warranted, because their prognosis is dependent on the Lin-Weiss-Bisceglia diagnosis.

Oncocytic variant of medullary thyroid carcinoma; a rare tumor with numerous diagnostic mimics by fine needle aspiration

Oncocytic variant of medullary thyroid carcinoma is rare form of thyroid carcinoma that is easily misdiagnosed on fine needle aspiration specimens due to it is low incidence and cytomorphologic overlap with other more common Hurtle cell lesions. A correct initial diagnosis by fine needle aspiration is imperative as the clinical treatment for medullary carcinoma differs significantly from the mimickers. We present a case of this rare variant tumor that on initial fine needle aspiration was described as a Hurthle cell lesion and was subsequently correctly classified on the resection specimen. In this brief review, we describe the cytomorphologic features of medullary carcinoma, oncocytic variant of medullary carcinoma and it is most common mimickers, and we discuss the ancillary studies required to confirm the diagnosis. This case highlights the importance of a complete clinical history and radiologic correlation, which in conjunction with a careful attention to the cytologic features of the fine needle aspiration sample, should in most cases ensure a correct initial diagnosis.

Cytologic diagnosis of adrenal oncocytic pheochromocytoma in a lung cancer patient: Report of a case and review of the literature

Adrenal oncocytic pheochromocytoma is an extremely rare type of pheochromocytoma. To the best of our knowledge, we present the first cytological diagnosis of this variant via fine-needle aspiration in an 81-year-old male patient who was found to have an adrenal mass while undergoing workup of the recently diagnosed lung adenocarcinoma. We describe the cytomorphologic findings in our case and provide a review of the reported cases of adrenal oncocytic pheochromocytoma – all of which appear to be benign, nonfunctional, occur in adults, and have similar morphologic features. The pathologist should be aware of this uncommon diagnostic entity and its potential diagnostic pitfalls.

Oncocytic-type intraductal papillary mucinous neoplasms: a unique malignant pancreatic tumor with good long-term prognosis

BACKGROUND

The different epithelial phenotypes of intraductal papillary mucinous neoplasms (IPMNs) are predictors of tumor biology and post-surgical outcomes. Oncocytic-type IPMN (O-IPMN) seems to have a unique natural history, but not much information is available because of its rarity. We sought to describe the characteristics of a cohort of patients resected for O-IPMNs, focusing on their long-term outcomes after surgery.

STUDY DESIGN

We conducted a retrospective review of the demographics, clinical presentation, pathology, and survival of a cohort of patients resected for IPMN between 1990 and 2013, comparing O-IPMN with other IPMN subtypes.

RESULTS

Eighteen of 400 patients (4.5%) who underwent resection for IPMN had the oncocytic subtype. Compared with other IPMN patients, those with O-IPMNs were more likely to be male (72% vs 45%; p = 0.02) and to have main pancreatic duct involvement (72% vs 42%; p = 0.01). Oncocytic IPMNs occurred in asymptomatic individuals in 67% of cases. They had either invasive carcinoma (61%) or high-grade dysplasia (39%), and the proportions in other epithelial subtypes were 19% and 21%, respectively (p < 0.001). After resection, the 10-year recurrence rate for O-IPMNs was 46%. Recurrences occurred up to 11 years after the initial resection and a completion total pancreatectomy was performed in 4 patients. At a median follow-up of 7 years, no patients with O-IPMN had died from the disease.

CONCLUSIONS

Oncocytic IPMN is a unique tumor subtype that occurs mostly in the main pancreatic duct and is malignant. Recurrences after resection are not uncommon and can occur more than 10 years after the initial resection. Reoperations for recurrent O-IPMN are often feasible and have excellent results in terms of survival.