Usefulness of Wieneke criteria in assessing morphologic characteristics of adrenocortical tumors in children.

PURPOSE: Adrenocortical tumors (ACT) occur rarely in pediatric age group. Pediatric ACTs behave differently from their histologically similar adult counterparts and standard adult criteria often cannot accurately predict their clinical behavior. The aim of the present study was to document the clinicopathologic spectrum of pediatric ACTs and to assess the utility of Wieneke scoring system in predicting clinical behavior of these tumors. METHODS: This multi-institutional study comprised of 13 cases of pediatric ACTs from January 2005 to May 2014. Clinical features and gross pathologic characteristics were obtained from records. Comprehensive analyses of microscopic features were performed. Each tumor was assessed according to criteria proposed by Wieneke et al. and was assigned to benign, intermediate for malignancy or malignant group. The standard adult Weiss criteria were also applied for comparison. RESULTS: There were total 6 cases of adrenocortical adenomas and 7 cases of adrenocortical carcinomas. Most of the children (76.9%) presented with endocrine dysfunction. Lower age of presentation was significantly associated with better prognosis. Applying Wieneke criteria, there were 6 benign and 6 malignant cases and one case was assigned to intermediate for malignancy group. The clinical behavior of all the cases was consistent with Wieneke criteria categorization. Applying Weiss criteria, 3 cases with benign clinical behavior were assigned to malignant group. CONCLUSION: Our study validates the reliability of Wieneke scoring system in predicting malignancy in pediatric ACTs. It is simple and easy to use and therefore useful in day-to-day practice.

Oncocytic lesions of the neuroendocrine system.

This paper reviews the pathologic features of lesions which are oncocytic and involve classic endocrine organs. The history of the oncocytic cell, its morphologic and ultrastructural features, and important immunohistochemical findings are reviewed. Oncocytic proliferations including non-neoplastic and neoplastic of the thyroid, parathyroid, adrenal (both cortex and medulla), and pituitary are described. Their clinical relevance, functional capacity and capability, and where appropriate, prognostic implications are discussed. Important and relevant molecular biological information is included where appropriate.

Ultrastructural findings in adrenal cortical adenomas clinically mimicking pheochromocytoma: a comparison with other adrenal tumors and tissue preparation techniques.

Adrenal cortical tumors clinically mimicking pheochromocytomas are extremely rare, with 14 cases in the literature. The authors describe 2 patients with adrenal cortical adenoma (ACA) and catecholamine elevations. The impact of tissue preparation methods on electron microscopy (EM) images was assessed in ACA mimicking pheochromocytoma, pheochromocytoma, and ACA lacking pheochromocytoma-like symptoms. Ten adrenal cortical tumors were examined using EM after a variety of tissue preparation techniques, including fixation with glutaraldehyde, formalin for varying lengths of time followed by glutaraldehyde, and/or formalin followed by paraffin embedding. Electron micrographs were assessed for image quality and the presence of dense secretory granules and eccentric, norepinephrine (NE)-type granules. Images created from tissue fixed in glutaraldehyde and/or formalin and embedded in resin were of good quality, while those derived from paraffin-embedded specimens were poor with disrupted cellular architecture. When pheochromocytoma was fixed in glutaraldehyde for 24 h or in formalin for 8 days, eccentric granules were identified. These granules were absent when tissue was fixed in formalin for 20 days or was obtained from a paraffin block. ACA without pheochromocytoma-like symptoms and ACA mimicking pheochromocytoma both had noneccentric dense-core granules on EM regardless of tissue preparation, and eccentric NE-type granules were absent. ACA is a rare cause of pheochromocytoma-like symptoms. These tumors lack eccentric, NE-type dense-core granules present in pheochromocytoma. Glutaraldehyde alone or formalin fixation followed by glutaraldehyde produces electron micrographs that may aid in the diagnosis of adrenal cortical tumors, whereas formalin-fixed, paraffin-embedded tissue results in images that are inadequate.

[Application of adrenocorticotropic hormone receptor determination and ultrastructural observation of tumor cells in the subtyping of adrenocortical neoplasms].

OBJECTIVE: To explore the values of adrenocorticotropic hormone receptor (ACTH-R) determination and ultrastructural observation of tumor cells in the subtyping of adrenocortical neoplasms (ANs). METHODS: The expression of ACTH-R in 87 AN tissues were determined with Polymer immunohistochemical staining, with 10 normal adrenal tissues as the controls. The ultrastructure of the tumor cells was observed using electron microscopy. RESULTS: The positive expression rate of ACTH-R was (80.1 +/- 8.2)%, (53.2 +/- 10.3)%, (63.2 +/- 10.1)%, (83.3 +/- 6.5)%, and (70.1 +/- 7.3)% in the sub-CPA group, CPA group, APA group, NFA group, and NC group, respectively. ACTH-R expression was significantly higher in NFA and sub-CPA groups than in NC group (P = 0.001, P = 0.000), APA group (P = 0.000, P = 0.000), and CPA group (P = 0.000, P = 0.000), and was also significantly different between NC group and APA group (P = 0.039) and between APA group and CPA group (P = 0.037). However, no significant difference was found between NFA group and sub-CPA group (P = 0.325). As shown by the electron microscopy, ANs had some partially similar microscopic features, while different AN subtypes showed differences in the type and amount of secretory granules. CONCLUSION: ACTH-R determination and ultrastructural observation of tumor cells may be helpful for subtyping ANs.

[Importance of proliferative potential (as the ratio of a proliferative cells number and duration of mitosis) in diagnoses of malignant degree and prognosis of adrenocortical cancer].

The aim of research has been the estimation of a proliferative potential as simultaneous detection of a proliferative cells number (Ki-67 index) and duration of mitosis (nucleolar argyrophilic protein expression--B23/nucleophosmin and C23/nucleolin) at patients with adrenocortical cancer. In according to lifetime of patients after operation 2 groups had been sorted out. The first one included patients surviving 56.12 months, the second one--9.25 months. We've found out that different aspects of tumor diagnosis as well distinction of benignant or malignant tumor growth, a malignant degree of tumors, a prognostic criteria of illness, survival of patients etc. must be characterized by total research both a proliferative cells fraction (Ki-67 index) and a rate of mitosis (expressions of B23/nucleophosmin and C23/nucleolin).

Oncocytic adrenal cortical tumor with cytoplasmic inclusions and hyaline globules.

Adrenal cortical tumors, particularly oncocytic tumors, have been reported to contain a variety of intracytoplasmic and intramitochondrial inclusions. Oncocytic cortical tumors can also morphologically mimic pheochromocytomas. We report an unusual, partially oncocytic cortical neoplasm with nesting architecture, intranuclear inclusions, and hyaline globules reminiscent of pheochromocytoma, together with numerous, small, brightly eosinophilic, periodic acid-Schiff-positive cytoplasmic inclusions and typical cytoplasmic lipid droplets. Ultrastructural study revealed oncocytes containing numerous mitochondria with intramitochondrial crystals and lipid droplets. Immunohistochemistry and immunoblots were utilized to further characterize the tumor. Immunohistochemistry demonstrated immunoreactivity of both the eosinophilic inclusions and the hyaline globules for adipose differentiation-related protein (ADRP), which is one of a group of proteins associated with storage of neutral lipids in many cell types. Immunoblots confirmed the presence of ADRP and demonstrated an imbalance between ADRP and perilipin, another neutral lipid-associated protein, in tumor tissue compared to normal adrenal cortex. The findings suggest that mitochondrial dysfunction in oncocytic cortical tumors may lead to abnormal processing of proteins related to the lipid-storing functions of the adrenal cortex, resulting in unusual cytoplasmic inclusions and extracellular globules resembling the globules in pheochromocytomas. The finding of ADRP as a constituent of inclusions in adrenal cortical tumors has not been previously reported.

Subclinical Cushing's syndrome associated with an adrenocortical oncocytoma.

Oncocytoma is a neoplasm that can arise in several organs, and it has been more commonly described in the kidney, salivary gland and thyroid. Oncocytoma arising in the adrenal gland is a rare finding. Moreover, functioning adrenocortical oncocytoma is exceptionally rare. A 47-yr-old man was incidentally discovered to have a right adrenal mass. The patient had no clinical features suggestive of increased adrenal function. However, hormonal evaluation showed a disturbed cortisol circadian rhythm, supranormal urinary cortisol excretion, a low level of ACTH, and a lack of suppressibility of cortisol secretion after dexamethasone. Right adrenalectomy was performed, and this revealed a well-circumscribed dark-brown tumor that measured 2.4x2.2 cm. The tumor consisted almost exclusively of large eosinophilic and epitheloid cells whose cytoplasm was packed with eosinophilic granulations, which corresponded to the numerous mitochondria confirmed on electron microscopy. This is a rare case of subclinical Cushing's syndrome that was caused by adrenocortical oncocytoma.

Tumor Cell Subtypes Based on the Intracellular Hormonal Activity in KCNJ5-Mutated Aldosterone-Producing Adenoma.

Aldosterone-producing adenomas (APAs) harbor marked intratumoral heterogeneity in terms of morphology, steroidogenesis, and genetics. However, an association of biological significance of morphologically identified tumor cell subtypes and genotypes is virtually unknown. KCNJ5 mutation is most frequently detected and generally considered a curable phenotype by adrenalectomy. Therefore, to explore the biological significance of KCNJ5 mutation in APA based on intracellular hormonal activities, 35 consecutively selected APAs (n=18; KCNJ5 mutated, n=17; wild type) were quantitatively examined in the whole tumor areas by newly developed digital image analysis incorporating their histological and ultrastructural features (14 cells from 2 KCNJ5-mutated APAs and 15 cells from 1 wild type) and CYP11B2 immunoreactivity. Results demonstrated that KCNJ5-mutated APAs had significantly lower nuclear/cytoplasm ratio and more abundant clear cells than wild type. CYP11B2 immunoreactivity was not significantly different between these genotypes, but a significant correlation was detected between the proportion of clear cells and CYP11B2 immunoreactivity in all of the APAs examined. CYP11B2 was predominantly immunolocalized in clear cells in KCNJ5-mutated APAs. Quantitative ultrastructural analysis revealed that KCNJ5-mutated APAs had significantly more abundant and smaller-sized mitochondria with well-developed cristae than wild type, whereas wild type had more abundant lipid droplets per unit area despite the small number of the cases examined. Our results did provide the novel insights into the morphological features of APA based on their biological significance. KCNJ5-mutated APAs were characterized by predominance of enlarged lipid-rich clear cells possibly resulting in increased neoplastic aldosterone biosynthesis.

Alternative lengthening of telomeres in the human adrenocortical carcinoma cell line H295R.

Telomere maintenance can occur in the absence of telomerase by a mechanism referred to as alternative lengthening of telomeres (ALT). ALT is considered to be rare in tumors of epithelial origin. The biological significance and molecular mechanism of ALT have not been well studied in human cancers. It has been reported that clinical samples of adrenocortical carcinoma show a low incidence of telomerase positivity. We characterized an adrenocortical carcinoma cell line, H295R, focusing on the telomere maintenance mechanism, and compared it with telomerase-positive 293 cells and HeLa cells. Telomerase activity could not be detected in H295R cells by the TRAP assay. Among the essential components of the telomerase holoenzyme, only hTERT expression was undetectable by RT-PCR, indicating that the lack of telomerase activity is due to suppression of hTERT. H295R cells had long and heterogeneous telomere DNA, and FISH revealed large nuclear bodies in a few interphase nuclei, which presumably represented ALT-associated PML bodies. These results suggest that H295R cells have the ALT phenotype. Several proteins that are possibly associated with the telomere maintenance mechanism were examined. TRF1 and TRF2 were expressed in H295R cells as well as in 293 cells and HeLa cells. The ratio of hnRNP B1 to A2 was higher in H295R cells than in 293 cells and HeLa cells. In conclusion, the H295R adrenocortical carcinoma cell line is negative for telomerase and maintains its telomeres by the ALT mechanism. We anticipate that H295R cells will be a good model for understanding the significance and mechanism of ALT in human cancers.

Gap junction assembly and endocytosis correlated with patterns of growth in a cultured adrenocortical tumor cell (SW-13).

After seeding at subconfluent densities, human adrenocortical adenocarcinoma cells (SW-13) proliferate to form a typical epithelial monolayer upon the culture vessel substratum. Single cells of the confluent monolayer are spontaneously released into the medium, however, where they may remain isolated or reaggregate with other floating cells. In this study, we examined the growth patterns of these cells in culture and analyzed alterations of their most prominent intercellular contact specialization, the gap junction, as cellular relationship changed during growth and development of the cell culture. We report here details of gap junction assembly during cellular aggregation and correlate the apparent endocytosis of gap junctions with the spontaneous release of single cells from the monolayer into the medium.

Establishment and characterization of a human adrenocortical carcinoma cell line that expresses multiple pathways of steroid biosynthesis.

We established a continuous cell line, NCI-H295, from an invasive primary adrenocortical carcinoma. The cell line was established in a fully defined medium (HITES) and later could be adapted for growth in a simple medium supplemented only with selenium, insulin, and transferrin and devoid of serum, steroids, fibroblast growth factor, and a source of exogenous cholesterol. NCI-H295 cells had a relatively long population doubling time and were tumorigenic when inoculated s.c. into athymic nude mice. The cultured cells had ultrastructural features of steroid-secreting cells and contained complex cytogenetic abnormalities including the presence of multiple marker chromosomes. Steroid analyses (radioimmunoassays and mass spectrometry), performed 7 to 9 years after culture initiation, demonstrated secretion of more than 30 steroids characteristic of adrenocortical cells. Total unconjugated steroid secretion in serum-supplemented medium was 2.83 micrograms/10(6) cells/24 h and about 4-fold less in serum-free medium. The major pathway of pregnenolone metabolism in NCI-H295 cells is androgen synthesis, with formation of dehydroepiandrosterone, androstenedione, testotesterone, and at least three sulfated androgens, as well as estrogens. In addition, formation of cortisol, corticosterone, aldosterone, and 11 beta-hydroxyandrostenidione indicated the presence of 11 beta-hydroxylase. Thus, multiple pathways of steroidogenesis are expressed by NCI-H295 cells, including formation of corticosteroids, mineralocorticoids, androgens, and estrogens. Our findings indicate the presence in NCI-H295 cells of all of the major adrenocortical enzyme systems, including 11 beta-hydroxylase, desmolase, 21 alpha-hydroxylase, 17 alpha-hydroxylase, 18-hydroxylase, lyase, sulfokinase, and aromatase. The NCI-H295 cell line should prove of value in studying the regulation, metabolic pathways, and enzymes involved in steroid formation and secretion. In addition, it may provide insights into the biology and treatment of adrenocortical carcinoma.

[Analysis of adrenocortical tumors morphology as regards their structure and potential malignancy]. / Analiza morfologii guzów kory nadnerczy pod wzgledem ich struktury i potencjalnej zlosliwosci.

INTRODUCTION: A consequence of diagnosis of adrenocortical carcinoma (ACC) is introduction of pharmacological therapy, precise monitoring of the patients and in some cases re-operation. The aim of the study is to analyse morphology of adrenocortical tumours as regards their malignancy by use of criteria proposed by Weiss. MATERIAL AND METHODS: 110 adrenocortical tumours in 107 patients were analysed (M 27.1%, F 72.9%; age 32 to 77 years, mean 55.2 +/- 9.7). Conn syndrome was diagnosed in 16 patients (14.9%), Cushing syndrome in 12 (11.2%), and virilisation in 3 (2.8%). In 76 patients (71.0%) biochemical tests did not reveal hormonal hyperactivity of the tumour. RESULTS: In routine histopatological examination ACC was diagnosed in 6 tumours (5.4%), adrenocortical adenoma (ACA) in 92 (83.6%) and adrenocortical hyperplasia in 12 (10.9%). Nuclear grade III or IV was observed in 8 tumours (7.3%), mitotic rate > 5/50 high power fields in 6 (5.4%), atypical mitoses in 5 (4.5%), clear cells constituting < 25% of the tumour in 10 (9.1%), diffuse architecture in 8 (7.3%), necrosis in 16 (14.5%), veins infiltration in 4 (3.6%), sinusoids infiltration in 7 (6.3%), and tumour capsule infiltration in 5 (4.5%). Among ACC tumours 4-9 features of malignancy were present, among ACA--0-3 features. Statistical analysis revealed correlation between number of criteria proposed by Weiss and maximal tumour size (p < 0.05). CONCLUSION: The structure and cell arrangement in adrenocortical adenoma are heterogeneous. Application of criteria proposed by Weiss in histopathological examination of adrenocortical tumours can be useful in differentiating adrenocortical adenoma from carcinoma.

Ultrastructural localization of cyclic adenosine 3',5'-monophosphate-dependent protein kinase after adrenocorticotropin stimulation in adrenal cortical tumor cells.

To increase our knowledge of the molecular details of peptide hormone action, a specific immunogold staining procedure for the ultrastructural localization of cAMP-dependent protein kinase regulatory (RI) and catalytic (C) subunits was used in Y-1 adrenal cortical tumor cells. The Y-1 adrenal cell responds to ACTH (40 mU/ml) with a decrease in cell division and an increase in steroid production. Corresponding to the decrease in rate of cell division and the increase in steroid production, there was a 2-fold increase in both nuclear and cytoplasmic localization of the C subunit after 60-min ACTH (40 mU/ml) treatment of the culture. The amount of immunogold staining in the adrenal tumor cells after localization with antiserum of the RI subunit decreased after 60-min ACTH (40 mU/ml) stimulation. A 2-fold decrease in labeling in the cytoplasm and nucleus was observed for the RI subunit. The loss of RI subunit from the soluble fraction of the cytoplasm of the cell or an alteration of this RI subunit is suggested by this investigation. Since there was no increase in the RI subunit in the nuclear compartment, a loss of RI subunit from the cytoplasm into the nucleus seems unlikely. The observed immunogold changes in the C subunit after ACTH treatment correspond to the reported changes observed with light microscopic techniques with a fluorescein-coupled inhibitor as a probe for the localization of free C. The immunogold technique allows for the ultra-structural identification and quantification of nuclear as well as the cytoplasmic sites of cAMP-dependent protein kinase after hormonal stimulation. These results support the proposed role of protein kinase as a mediator of the ACTH response.

Alpha1 connexin 43 gap junctions are decreased in human adrenocortical tumors.

Gap junctional communication disorders have been implicated in the etiology of benign and malignant tumors. Understanding the type, distribution, and frequency of gap junctions in adrenal disorders should provide insight into the role of gap junctions in adrenal carcinogenesis as well as information that may be useful in developing improved diagnosis and treatment of adrenal diseases. Using immunocytochemical techniques, we have characterized and compared alpha1 connexins 43 gap junction protein levels in normal adrenal glands to those in benign and malignant adrenocortical human tumors. In addition, gap junction protein levels were studied in a human adrenal cancer cell line (H295). In both normal and neoplastic adrenal tissues, only alpha1 connexin 43 could be detected, whereas beta1 connexin 32 and beta2 connexin 26 were not found. In the normal adrenal gland, the zona fasciculata was demonstrated to have the highest number of gap junctions per cell (mean +/- SEM, 13.78 +/- 1.93). In contrast, in benign adrenocortical adenomas, the number of gap junctions per cell compared to that detected in normal adrenal glands was significantly reduced (mean +/- SEM, 4.6 +/- 1.17; P < or = 0.05), and the lowest number was found in malignant adrenocortical tumors (1.42 +/- 0.58; P < or = 0.05). Similarly, there were few or no alpha1 connexin 43 gap junctions in the H295 population. There was a progressive decrease in gap junction plaques in adrenocortical cancer cell populations compared to those in normal cell populations. Therefore, analysis of gap junction protein may be helpful for the differential diagnosis of benign and malignant adrenal tumors. The induction of gap junctions in malignant cells may provide a novel therapeutic strategy for adrenal cancer.

Myxoid neoplasms of the adrenal cortex: a rare histologic variant.

The myxoid variant of adrenocortical carcinoma is a rare neoplasm described previously in only two case reports. Because of the rarity of these lesions, the presence of myxoid changes in adrenal cortical neoplasms usually raises the possibility of malignancy. We studied the histopathologic features of 14 cases of myxoid adrenocortical neoplasms, including six adenomas and eight carcinomas. All patients with adenomas with sufficient follow-up (n = 5) were alive with no recurrence of their tumors or evidence of metastatic disease. Four patients with carcinomas died of their disease, two were alive with metastatic disease, and one was alive with no evidence of recurrence or metastatic disease. Histologically, the 14 tumors varied in their myxoid composition, ranging from 10% to 95%. The myxoid foci stained positively with Alcian blue and were usually negative with periodic acid-Schiff and mucicarmine stains. As a group, the immunophenotype of the lesions was typical of other adrenal cortical neoplasms, with positive immunostaining for vimentin, synaptophysin, and alpha-inhibin. One tumor was focally positive for keratin. Myxoid adrenal cortical neoplasms should be included in the differential diagnosis of myxoid retroperitoneal neoplasms. Myxoid changes in adrenal cortical neoplasms may be present in both adenomas and carcinomas, and the usual clinical and histopathologic features for adrenocortical neoplasms should be used to diagnose these neoplasms.

Adrenocortical oncocytoma. A true nonfunctioning adrenocortical tumor.

We studied three cases of adrenocortical neoplasms that were detected incidentally after radiological examination of the abdomen. These cases did not demonstrate any clinical evidence of adrenocortical abnormalities, such as virilization. Macroscopically, the tumors were light to dark tan on cut surface. Light-microscopic examination revealed compact cells with abundant lipid-sparse eosinophilic cytoplasm and occasional enlarged nuclei. In one case, ultrastructural observation demonstrated abundant mitochondria. Immunohistochemical examination of all of the adrenocortical steroidogenic enzymes showed that none of the cases had immunoreactivity. No mitotic activity and no vascular invasion was observed. The postoperative course were uneventful. The follow-up interval varied from 8 to 27 months. These three neoplasms apparently represent the first reported cases of adrenocortical oncocytoma. They can be considered true nonfunctioning adrenocortical neoplasms because steroidogenic enzymes required for corticosteroid biosynthesis were not expressed in the tumor cells.

Adrenal cortical adenoma in the spinal canal of an 8-year-old girl.

An ectopic adrenal cortical adenoma containing high levels of androstenedione but without clinically detectable virilizing effects was found in the spinal intradural space of an 8-year-old girl. The tumor, which was located at the L2 level, manifested itself clinically by a short history of bilateral leg pain. It was well encapsulated; therefore, total surgical removal was accomplished. The light microscopic appearance of the tumor was typical of adenomatous adrenal cortical tissue. Ultrastructurally, it also showed characteristic features of steroid-producing tumors, including very abundant smooth endoplasmic reticulum and giant mitochondria with tubulovesicular and circular cristae. Frozen tissue analyzed by radioimmunoassay was found to contain almost 20 times the normal tissue level of androstenedione. There was no elevation of cortisol or aldosterone levels in the tumor. Postoperative magnetic resonance imaging (MRI) scan of the retroperitoneum showed no abnormalities in the patient's adrenal glands. Serum androstenedione levels were normal. We postulate that the adenoma developed from congenital ectopic rests of intraspinal adrenal tissue. Although ectopic occurrence of adrenal cortical tissue has been recorded in other areas, neither such rests nor tumors developing from them have been previously reported within the spinal canal.

Oncocytic adrenocortical neoplasms: a report of seven cases and review of the literature.

Oncocytic neoplasms of the adrenal gland are rare. We describe the clinicopathologic and immunohistochemical findings of seven oncocytic adrenocortical neoplasms, five oncocytomas, and two oncocytic neoplasms of uncertain malignant potential. Three tumors were studied using electron microscopy. These neoplasms occurred in five women and two men (median age, 55 years) with no clinical evidence that the neoplasms were functional. The size of the neoplasms varied from 5.0 cm to 13.5 cm. Histologically, each neoplasm was composed exclusively of oncocytes. The oncocytomas had very low or absent mitotic activity and no evidence of necrosis. The two oncocytic neoplasms of uncertain malignant potential had increased mitotic activity and necrosis but no evidence of invasion or metastases. Nuclear atypia, either focal or generalized, was found in all neoplasms. Immunohistochemical studies performed using fixed, paraffin-embedded sections showed strong reactivity with the mitochondrial antibody mES-13 in all neoplasms. Four of five oncocytomas and one oncocytic neoplasm of uncertain malignant potential expressed keratin, predominantly keratin 18, as shown using the CAM 5.2 and AE3 antibodies. Two neuroendocrine-associated markers, neuron specific enolase and synaptophysin, were positive in seven and five neoplasms, respectively. However, all neoplasms were negative for the other neuroendocrine markers tested, including chromogranin A, tyrosine hydroxylase, and dopamine beta-hydroxylase, as well as for epithelial membrane antigen, S100, and p53. Using the MIB-1 (Ki-67) antibody, proliferative activity was increased in both oncocytic neoplasms of uncertain malignant potential. All six patients with available clinical follow-up data are alive without evidence disease, although the follow-up interval is relatively short (< 2 years) for the two patients with oncocytic neoplasms of uncertain malignant potential. We conclude that oncocytic adrenocortical neoplasms are nonfunctional tumors that can become large before they are detected by radiologic studies. The majority of neoplasms are benign and should not be misdiagnosed as carcinoma.

Adrenocortical blastoma.

We report a previously undescribed virilizing malignant adrenocortical tumor in an 21-month-old infant with elevated serum alphafetoprotein. The tumor consists of a peculiar mixture of immature epithelial and mesenchymal elements as well as slit-like spaces partially lined by primitive epithelial cells. Focally, the tumor has features reminiscent of the normal embryologic development of the adrenal cortex. A panel of immunohistochemical stains revealed only vimentin reactivity. We propose the term "adrenocortical blastoma" for this unusual neoplasm.

The pathology of adrenocortical neoplasia: a correlated structural and functional approach to the diagnosis of malignant disease.

The structural and functional characteristics of nine functioning adrenocortical tumors (four adenomas and five carcinomas) causing Cushing's syndrome or virilization were studied. All tumors that we considered to show histologic evidence of malignant disease and that subsequently metastasized or recurred also showed in cell culture at least one significant functional or behavioral difference from benign tumors. No single defect was common to all carcinomas, but predominant changes included secretion of precursor steroids, such as 11-deoxycortisol (S) and a blunted or absent response to ACTH. All adenomase examined were normal in these respects in comparison with nondiseased cortical cells in culture. In carcinomas whose functions deviated only minimally from normal the presence of highly differentiated ultrastructural characteristics did not, however, confer a better prognosis.