Immunohistochemical study of adrenocortical carcinoma. Predictive value of the D11 monoclonal antibody

Outcome of brain metastases from adrenocortical carcinoma: a pooled analysis

PURPOSE

Brain metastases rarely complicate the natural history of patients with adrenocortical carcinoma (ACC). No information is available regarding the life expectancy and efficacy of treatments in ACC patients with brain involvement.

METHODS

A pooled analysis was performed by searching on PubMed and using the keywords: "brain metastases in adrenocortical carcinoma", and "leptomeningeal metastases in adrenocortical carcinoma". Four patients diagnosed at Spedali Civili Hospital in Brescia were added to the analysis. Data concerning demographic, disease characteristics, adopted treatments and patient prognosis were collected.

RESULTS

A total of 27 patients (18 adults and 9 children) were included in this study, 22 of them had an adequate follow-up. Brain metastases occurred late in the natural history of adult patients but not in that of children. Surgery plus/minus radiation therapy was the treatment of choice. Adult patients with brain metastases had a poor prognosis with a median progression-free survival (PFS) and overall survival (OS) of 2 and 7 months, respectively. Median PFS and OS were not attained in children.

CONCLUSION

Brain metastases in ACC patients are rare and are associated with poor prognosis, particularly in adults. Surgery plus/minus radiotherapy is the only therapeutic approach that can offer patients a chance to obtain durable local disease control.

Leptomeningeal Metastasis from Adrenocortical Carcinoma: A Case Report

Adrenocortical carcinoma (ACC) is an uncommon endocrine malignancy with limited treatment options. While the overall 5-year survival rate in patients with ACC is 35%, the disease is often rapidly progressive with long-term survival in only 5% of patients. Although tumor stage, grade, and excess hormonal activity predict unfavorable prognosis, additional biomarkers are needed to identify patients with aggressive disease. A 23-year-old woman presented with rapidly progressing signs and symptoms of Cushing's syndrome, with associated abdominal pain and fullness. Evaluation revealed a large left adrenal mass which had developed over 8 months. En bloc surgical resection was performed by an endocrine surgeon, and pathology revealed adrenocortical carcinoma with Ki67 of 60%. Despite adjuvant treatment with mitotane and etoposide-doxorubicin-carboplatin chemotherapy, the patient had rapid disease progression with metastatic spread to liver, lung, bone, brain, and leptomeningies, and she died 11 months after the initial diagnosis. Subsequent analysis of the patient's tumor revealed mutations in TP53 and MEN1. RNA sequencing was compared against the the Cancer Genome Atlas data set and clustered with the high steroid, proliferative subtype, associated with the worst prognosis. The tumor also demonstrated a low BUB1B/PINK1 ratio and G0S2 hypermethylation, both predictive of very aggressive ACC. This case represents a subset of ACC characterized by rapid and fatal progression. Clinically available predictors as well as recently reported molecular signatures and biomarkers correlated with this tumor's aggressiveness, suggesting that development and validation of combinations of biomarkers may be useful in guiding personalized approaches to patients with ACC.

Proliferating Cell Nuclear Antigen Immunoreaction in Adrenal Tumors

Aims and background

We studied, retrospectively, 33 cases of adrenal tumors of children at the Pediatric Endocrinology Unit, Children's Institute, São Paulo State University Medical School, from 1975 to 1993. All patients had at least 2 years of follow-up with a few exceptions.

Methods

Clinical follow-up data were correlated with histopathologic review, laboratory data and cell kinetic evaluation (based on detection of proliferating cell nuclear antigens).

Results

With one exception, all the patients had presented signs of androgen production and had high levels of dehydro-epiandrosterone-sulfate. Tumor weight evaluation represented a good parameter of neoplasm evolution: of 19 cases weighing less than 250 g, 17 had no evidence of disease after surgery, and 2 had an unfavorable prognosis. Of 14 cases weighing more than 250 g, only 1 had no evidence of disease and 13 had an unfavorable evolution.

Conclusions

Proliferating cell nuclear antigen (PCNA) was not helpful to evaluate adrenal neoplasm evolution: our study did not show any correlation between PCNA score and prognosis.

Clinical and pathological analysis of 116 cases of adult adrenal cortical adenoma and literature review

BACKGROUND

The aim of this study is to investigate origin, gross features, microscopic features, immunohistochemical properties, and differential diagnosis of adrenal cortical adenoma (ACA) in patients ≥20 years old.

METHODS

The clinicopathological features of 116 cases of ACA and the immunohistochemical features of 50 cases of ACA were evaluated, and the relevant literature was reviewed.

RESULTS

In our cohort, 76.72% (89/116) of the cases were functional, and 27 cases had non-functional, benign adrenal adenomas. ACA presented as an island tumor with an envelope, and the mean tumor size was 3.6 cm (range 1-5 cm), with a mean tumor weight of 9.28 g (range 5-113 g). The shape of the tumor cells was consistent, and mitosis was rarely observed. Forty of the 46 patients with cortisol-secreting ACA had tumors containing granule cells. Primary aldosteronism was observed in 43 cases. Thirty-eight cases had endoscopically visible tumors, with clear cells and lipid-rich cytoplasm arranged in irregular patches or strips. Cortisol-producing ACAs were associated with atrophy of the non-tumorous cortex. Adrenocortical adenomas displayed positive immunohistochemical staining for MELAN-A, Syn (46 of 50 cases of ACA), NSE (44 of 50 cases of ACA), Vim (42 of 50 cases of ACA) and Ki-67 <5% (24 of 50 cases of ACA; the remaining 26 cases were negative for Ki-67).

CONCLUSION

Prediction of endocrine syndrome in functional ACA was possible based on its structure and morphologic features, which could prevent an unanticipated postoperative crisis. However, a clinical study is needed to validate these findings.

Pathology of the adrenal cortex: a reappraisal of the past 25 years focusing on adrenal cortical tumors

A reappraisal of the major advances in the diagnostic pathology of adrenal cortical lesions and tumors in the last 25 years is presented, with special reference to the definition of malignancy in primary adrenal cancer and its variants. Slightly more than 25 years ago, Weiss proposed his diagnostic scoring system for adrenal cortical carcinoma. This represented a milestone for adrenal pathologists and the starting point for further modifications of the system, either through minor changes in the scoring procedure itself or concentrating on some particular Weiss criterion such as mitotic index, integrated into alternative scoring schemes or algorithms that are currently under validation. Improvements in diagnostic immunohistochemistry have led to the identification of markers of cortical origin, such as Melan-A, alpha-inhibin, and SF-1 and of prognostic factors in carcinoma, such as the Ki-67 proliferation index and SF-1 itself. With regard to hyperplastic conditions, genetic investigations have allowed the association of the majority of cases of primary pigmented nodular adrenocortical disease (PPNAD) in Carney complex to mutations in the gene encoding the regulatory subunit 1A of protein kinase A (PRKAR1A). Other hereditary conditions are also associated with adrenal cortical tumors, including the Li-Fraumeni, Beckwith-Wiedemann, Gardner, multiple endocrine neoplasia type 1, and neurofibromatosis type 1 syndromes. Moreover, several advances have been made in the knowledge of the molecular background of sporadic tumors, and a number of molecules/genes are of particular interest as potential diagnostic and prognostic biomarkers.

Adrenal cortical tumors, pheochromocytomas and paragangliomas

Distinguishing adrenal cortical adenomas from carcinomas may be a difficult diagnostic problem. The criteria of Weiss are very useful because of their reliance on histologic features. From a practical perspective, the most useful criteria to separate adenomas from carcinomas include tumor size, presence of necrosis and mitotic activity including atypical mitoses. Adrenal cortical neoplasms in pediatric patients are more difficult to diagnose and to separate adenomas from carcinomas. The diagnosis of pediatric adrenal cortical carcinoma requires a higher tumor weight, larger tumor size and more mitoses compared with carcinomas in adults. Pheochromocytomas are chromaffin-derived tumors that develop in the adrenal gland. Paragangliomas are tumors arising from paraganglia that are distributed along the parasympathetic nerves and sympathetic chain. Positive staining for chromogranin and synaptophysin is present in the chief cells, whereas the sustentacular cells are positive for S100 protein. Hereditary conditions associated with pheochromocytomas include multiple endocrine neoplasia 2A and 2B, Von Hippel-Lindau disease and neurofibromatosis I. Hereditary paraganglioma syndromes with mutations of SDHB, SDHC and SDHD are associated with paragangliomas and some pheochromocytomas.

A tissue microarray-based comparative analysis of novel and traditional immunohistochemical markers in the distinction between adrenal cortical lesions and pheochromocytoma

We have encountered an increasing number of image-guided adrenal mass biopsies in which the differential diagnosis is adrenal cortical lesion versus pheochromocytoma. This distinction is sometimes difficult because of confounding clinical presentations, overlapping morphologies, and some degree of immunophenotypic overlap including focal staining with markers of purported lineage specificity. Interventional radiologists commonly use narrow gauge biopsy needles in this setting, which yield scant diagnostic tissue and further complicate pathologic evaluation. In this study, a detailed immunoprofile of 63 adrenal cortical lesions (3 adrenal rests, 6 adrenal cortical hyperplasias, 43 adrenal cortical adenomas, 4 adrenal cortical neoplasms of uncertain malignant potential, and 7 adrenal cortical carcinomas) was compared with 35 pheochromocytomas using traditional (calretinin, chromogranin, inhibin, melanA, and synaptophysin) and novel [steroidogenic factor-1 (SF-1), microtubule-associated protein 2, and mammalian achaete-scute homolog-1] antibodies, using tissue microarray technology to simulate small image-guided biopsies. Staining extent and intensity were each scored semiquantitatively for each antibody. A comparison of sensitivity and specificity using different intensity thresholds required for a "positive" result (> or = 1+ vs. > or = 2+) was performed. Staining results based on a > or = 1+ and (> or = 2+) intensity threshold were as follows: calretinin-95% (89%) in adrenal cortical lesions and 14% (0%) in pheochromocytomas; chromogranin-0% in adrenal cortical lesions and 100% in pheochromocytomas; inhibin-97% (86%) in adrenal cortical lesions and 6% (0%) in pheochromocytomas; microtubule-associated protein 2-29% (16%) in adrenal cortical lesions and 100% (89%) in pheochromocytomas; mammalian achaete-scute homolog-1-0% in both adrenal cortical lesions and pheochromocytomas; melanA-94% (86%) in adrenal cortical lesions and 6% (0%) in pheochromocytomas; SF-1-87% (86%) in adrenal cortical lesions and 0% in pheochromocytomas; synaptophysin-67% (59%) in adrenal cortical lesions and 100% in pheochromocytomas. Using an antibody panel consisting of chromogranin plus the nuclear antibody SF-1 and either calretinin or inhibin, while requiring a high-staining intensity threshold, helps to eliminate interpretative issues of artifactual or background reactivity, improves diagnostic sensitivity/specificity, and makes for an effective immunohistochemical approach in distinguishing adrenal cortical lesions from pheochromocytomas.

Adrenocortical carcinoma

ACC is a rare clinical entity that carries a poor prognosis; early diagnosis and complete surgical resection are associated with the improvement in patient survival. Even with appropriated diagnosis and treatment, most patients will develop recurrence and succumb to ACC because of the underlying tumor biology, the difficulty of achieving a complete resection, and the lack of effective systemic therapies. Despite its many drawbacks, mitotane continues to be a mainstay in the treatment of high-risk patients with ACC, especially those with recurrent or metastatic disease. Recent findings suggest that mitotane, combined with conventional chemotherapeutic agents, may improve survival for such patients.

Pediatric adrenal cortical carcinoma: brain metastases and relationship to NF-1, case reports and review of the literature

Adrenal cortical carcinoma (ACC) is a rare childhood neoplasm that seldom manifests brain metastases; hence few papers in the literature focus on neurological manifestations associated with ACC. Although ACC is known to be a signature tumor type in several inherited cancer predisposition syndromes, particularly Li Fraumeni, ACC has not been previously associated with neurofibromatosis, type 1 (NF-1), an inherited disorder with frequent CNS lesions that might prompt concern for metastatic disease by neuroimaging studies. We present two pediatric patients with ACC and unusual CNS findings. The first child developed metastasis to the brain 4 years after resection of his adrenal primary and 2 and 1 years, respectively, after metastases to the liver and lungs. Soon after our experience with this patient, a girl with known NF-1 presented with virilization; adrenalectomy disclosed an ACC and systemic metastases were found within months. Disseminated disease prompted concern that her complex intracranial lesions identified by neuroimaging studies might represent brain metastases, but this proved to be NF1-related hamartomatous lesions. We review the literature on ACCs in pediatric patients regarding brain metastases and previous associations with NF-1.

Recent advances in histopathology and immunohistochemistry of adrenocortical carcinoma

Discerning malignancy in resected adrenocortical neoplasms can pose diagnostic difficulty. Macroscopic examination is the first important step toward diagnosis and should include accurate measurement of weight and dimension of the specimens and description of the cut surface of the tumors. It is also important to sample the specimens for histological diagnosis near foci of hemorrhage and/or necrosis. Histological scoring systems evaluating multiple parameters, especially the criteria of Weiss, have been shown to be reliable in differential diagnosis between adrenocortical adenoma and carcinoma. A tumor is defined as adrenocortical carcinoma when three or more of the following criteria are met; (1) high nuclear grade, (2) mitotic rate six or more per 50 high power fields, (3) atypical mitosis, (4) clear cells less than 25%, (5) a diffuse architecture pattern in more than one-third of the tumor, (6) confluent necrosis, (7) venous invasion, (8) sinusoidal invasion, and (9) capsular invasion. The criteria are relatively straightforward and considered the most effective standard for diagnosis of adrenocortical malignancy. However, great care should be taken in applying the criteria to histological evaluation of two relatively rare and peculiar adrenocortical tumors, adrenocortical oncocytoma and pediatric adrenocortical neoplasms. At this juncture, ancillary biological or molecular markers are of little practical value in terms of differential diagnosis between adrenocortical adenoma and carcinoma but tumors with MIB1 or Ki-67 labeling index more than 2.5 may be considered malignant. Prognostic markers of adrenocortical carcinoma have not been established other than complete respectability of the tumor. There are also no surrogate markers for predicting response to therapy with Mitotane, an adrenolytic agent. It sometimes is important for surgical pathologists to differentiate adrenocortical carcinoma from metastatic malignancies of other sites. An immunohistochemical evaluation of adrenal 4 binding protein (Ad4BP) or SF-1, a transcription factor of all steroidogenesis, can aid in this differential diagnosis because nuclear immunoreactivity for this transcription factor is relatively specific to steroid producing cells.

Practical markers used in the diagnosis of endocrine tumors

Endocrine tumors constitute a large group of neoplasms that are widely dispersed throughout the body. They are made up mostly of neuroendocrine tumors (NE), which are characterized by the presence of secretory granules and production of peptide hormones, and non-NE tumors such as those derived from thyroid follicular cells and adrenal cortical cells. Immunohistochemical markers have been used to characterize these lesions and distinguish them from other histologically similar tumors. Chromogranin and synaptophysin are the most widely used broad-spectrum neuroendocrine tumor markers. The use of antibodies to transcription factors, keratins, and specific peptides is quite valuable in the diagnosis of endocrine tumors. This article reviews the common markers used to characterize endocrine tumors and to recognize tumors involved in the differential diagnosis of specific lesions.

The clinically inapparent adrenal mass: update in diagnosis and management

Clinically inapparent adrenal masses are incidentally detected after imaging studies conducted for reasons other than the evaluation of the adrenal glands. They have frequently been referred to as adrenal incidentalomas. In preparation for a National Institutes of Health State-of-the-Science Conference on this topic, extensive literature research, including Medline, BIOSIS, and Embase between 1966 and July 2002, as well as references of published metaanalyses and selected review articles identified more than 5400 citations. Based on 699 articles that were retrieved for further examination, we provide a comprehensive update of the diagnostic and therapeutic approaches focusing on endocrine and radiological features as well as surgical options. In addition, we present recent developments in the discovery of tumor markers, endocrine testing for subclinical disease including autonomous glucocorticoid hypersecretion and silent pheochromocytoma, novel imaging techniques, and minimally invasive surgery. Based on the statements of the conference, the available literature, and ongoing studies, our aim is to provide practical recommendations for the management of this common entity and to highlight areas for future studies and research.

Adrenal cortical neoplasms in the pediatric population: a clinicopathologic and immunophenotypic analysis of 83 patients

Adrenal cortical neoplasms in pediatric patients (<20 years) are rare. The clinical manifestations and biologic behavior of these lesions can be quite distinct from their histologically similar counterparts in the adult population, making pathologic criteria for distinguishing benign from malignant tumors equivocal. We undertook a study of 83 adrenal cortical neoplasms to determine if adult clinical and histologic features can be applied to pediatric patients in an outcome-based analysis. Most of the patients (50 girls and 33 boys) presented with hormone-related symptoms present for a mean of 6.8 months. The tumors ranged in size from 2 to 20 cm (mean 8.8 cm). Histologic parameters examined included capsular and/or vascular invasion, extraadrenal soft tissue extension, growth pattern, cellularity, necrosis, cytoplasmic eosinophilia, nuclear pleomorphism, nuclear-to-cytoplasmic ratio, prominent nucleoli, mitotic figures, atypical mitotic figures, bands of fibrosis, and calcifications. Immunophenotypically, there was reactivity with inhibin, vimentin, CK5, and focally with p53 and Ki-67. All patients underwent adrenalectomy, and 20 patients received adjuvant therapy. All patients with tumors classified as adenomas (n = 9) were alive, without evidence of disease (mean 14.7 years), whereas 21 patients with carcinomas had died with disease (mean 2.4 years). Only 31% of histologically malignant tumors behaved in a clinically malignant fashion. Features associated with an increased probability of a malignant clinical behavior included tumor weight (>400 g), tumor size (>10.5 cm), vena cava invasion, capsular and/or vascular invasion, extension into periadrenal soft tissue, confluent necrosis, severe nuclear atypia, >15 mitotic figures/20 high power fields, and the presence of atypical mitotic figures. Vena cava invasion, necrosis, and increased mitotic activity (>15 mitotic figures/20 high power fields) independently suggest malignant clinical behavior in multivariate analysis.

CD10 facilitates the diagnosis of metastatic renal cell carcinoma from primary adrenal cortical neoplasm in adrenal fine-needle aspiration

Renal cell carcinoma (RCC) frequently metastasizes or invades the adrenal gland. Metastatic RCC is often difficult to differentiate from primary adrenal cortical neoplasm (ACN) in an adrenal fine-needle aspiration (FNA). Recently, CD10 immunoreactivity was observed in more than 90% of RCC, but none in primary ACN. To facilitate the accurate diagnosis of metastatic RCC in adrenal FNA, we retrospectively studied the cytomorphology and CD10 immunohistochemistry in 20 cases of FNA specimens, including 10 cases of adrenal FNA (six cases of metastatic RCC and four cases of primary ACN) and 10 cases of primary RCC. Cytomorphologically, several overlapping features were observed between primary ACN and metastatic RCC, including: abundant clear cytoplasm, often with microvesicles, large nuclei with prominent nucleoli, bare nuclei, and prominent vascularity. Immunostaining for CD10 was positive in 9/10 cases of primary RCC, 5/6 cases of metastatic RCC in the adrenal gland, and 0/4 cases of primary ACN. Our study indicates that: 1) an accurate diagnosis of ACN in FNA specimens can often be difficult due to overlapping cytomorphologic features with RCC, and 2) CD10 immunostaining is helpful in separating metastatic RCC from a primary ACN and can reliably be performed on a cytologic sample.

A103 immunostaining in the diagnosis of adrenal cortical tumors: an immunohistochemical study of 316 cases

CONTEXT

The monoclonal antibody A103 recognizes an antigen on melanoma cells known as Melan-A or MART-1. Recent studies have shown that A103 also reacts with adrenal cortical cells and may be useful in the diagnosis of adrenal cortical tumors. However, only small numbers of some of the tumors in the differential diagnosis of adrenal cortical neoplasms have been studied.

OBJECTIVE

To study the specificity of A103 immunohistochemistry in a large number of tumors in the differential diagnosis of adrenal cortical neoplasms.

DESIGN

Formalin-fixed, paraffin-embedded tissue from 21 adrenal cortical tumors, 16 cases of metastatic carcinoma to the adrenal, 10 pheochromocytomas, and 269 extra-adrenal carcinomas was evaluated for A103 immunoreactivity using a commercially available antibody (Novocastra, Newcastle, UK).

RESULTS

Positive staining was seen in all of the adrenal cortical tumors but in none of the adrenal metastases or pheochromocytomas. In the 269 extra-adrenal carcinomas, A103 immunoreactivity was limited to a single ovarian serous carcinoma.

CONCLUSION

A103 immunostaining is useful in distinguishing adrenal cortical neoplasms from other carcinomas and pheochromocytoma.

N-cadherin expression in adrenal tumors: upregulation in malignant pheochromocytoma and downregulation in adrenocortical carcinoma

Cell adhesion molecules (CAMs) are important regulators of tumor growth. The aim of the present study was to evaluate the expression pattern of CAMs in adrenal tumors regarding origin (cortex vs medulla) and biologic behavior (benign vs malignant). Eighty seven adrenal tumors were investigated by immunocytochemistry (ICC) using monoclonal antibodies against N-cadherin (NCAD), E-cadherin (ECAD), neural cell adhesion molecule (NCAM), and CD44. Western blotting was performed on 30 tumors using the same antibodies. Markers for proliferation (Ki-67) and catecholamine synthesis (tyrosine hydroxylase) were also analyzed in tumors by ICC. NCAD was expressed in 12/27 benign pheochromocytomas (BPCs) (12 familial cases), 8/8 malignant pheochromocytomas (MPCs), 28/30 adrenocortical adenomas, and 9/22 adrenocortical carcinomas. ECAD was expressed in 0/27 BPCs, 0/8 MPCs, 0/30 adrenocortical adenomas, and 2/22 adrenocortical carcinomas. NCAM was expressed in 26/27 BPCs, 7/8 MPCs, 21/30 adrenocortical adenomas, and 17/22 adrenocortical carcinomas. CD44 was expressed in 23/27 BPCs, 6/8 MPCs, 7/30 adrenocortical adenomas, and 4/22 adrenocortical carcinomas. Both cortical and medullary adrenal tumors expressed NCAD, NCAM, and CD44 but were devoid of ECAD. The expression of CD44 and NCAM did not correlate with the malignant potential of tumors. NCAD was upregulated in MPCs, but downregulated in adrenocortical carcinoma. Thus, NCAD appears to be involved in the development of both cortical and medullary adrenal tumors.

Adrenocortical carcinoma with cerebral metastasis in a child: case report and review of the literature

OBJECTIVE AND IMPORTANCE

Adrenocortical carcinoma (ACC) is rare in the pediatric population, and brain metastasis seldom occurs.

CLINICAL PRESENTATION

The authors report a case of metastatic ACC to the brain in a 9-year-old patient who had an adrenal cortex neoplasm removed at 4 years of age, and was free of symptoms for 5 years. Two weeks before admission she complained of blurred vision in both eyes.

INTERVENTION

Examination revealed bilateral papilledema, and a Magnetic Resonance Imaging (MRI) of the brain revealed a mass in the left lateral ventricle with extensive vasogenic edema and hydrocephalus. The tumor was removed, and histopathologic examination demonstrated metastatic ACC.

CONCLUSION

Although ACC is a rare neoplasm it must be considered in the differential diagnosis of cerebral lesions in patients with a history of this tumor. Periodic long-term brain imaging is suggested as part of the follow up in patients with adrenocortical neoplasms.

Recent advances in surgical pathology of adrenal incidentaloma

Adrenal incidentaloma has recently increased in number because of the advances in radiologic diagnostic means. The clinical management and histopathological diagnosis of the resected adrenal mass has therefore become increasingly important. When evaluating the resected adrenal mass of the patients with adrenal incidentaloma, it is very important to evaluate the following aspects: 1) is the mass functional or not? 2) is the mass malignant or not? and 3) is the mass of adrenocortical origin or not? In this mini review, the recent advances in endocrine pathology of adrenal incidentaloma are briefly summarized, with emphasis on the three aspects above,

Diagnostic utility of the monoclonal antibody A103 in fine-needle aspiration biopsies of the adrenal

Fine-needle aspiration (FNA) of the adrenal is a useful modality for the evaluation of primary and metastatic neoplasms. Until now, however, few reliable markers existed for the positive identification of adrenal cortical cells. Originally studied as a melanoma marker, Melan-A, as detected by the murine monoclonal antibody, A103, has gained recent attention as a marker for steroid-producing cells. Formalin-fixed, paraffin-embedded cell blocks from 24 adrenal FNA specimens were stained for cytokeratins (AE1/AE3) and Melan-A (A103). Seven of 8 cases containing normal, hyperplastic, and neoplastic adrenal cortical cells were positive for A103. Among 16 cases of metastatic carcinoma, tumor cells in 14 samples were positive for cytokeratins but negative for A103. The A103 monoclonal antibody is a sensitive marker for the identification of normal, hyperplastic, and neoplastic adrenal cortical cells in cell blocks of adrenal FNA specimens. With the exception of melanoma, A103 reactivity is restricted to adrenal cortical and other steroid-producing cells. A103 should be used routinely for the evaluation of FNA specimens of adrenal mass lesions.

Immunoreactivity for A103, an antibody to melan-A (Mart-1), in adrenocortical and other steroid tumors

The Melan-A (MART-1) gene encodes an antigen recognized by cytotoxic T cells. It has been said to be restricted in its expression to melanocytes. However, here we report the presence of immunoreactivity for A103, an antibody to Melan-A, in five adrenocortical adenomas, 16 primary and 13 metastatic adrenocortical carcinomas, four Leydig cell tumors of the testis, and three Sertoli-Leydig cell tumors of the ovary. To evaluate the potential diagnostic role of this antibody, we studied immunoreactivity for A103 in 111 carcinomas, 40 germ cell tumors, and 33 miscellaneous nonmelanocytic epithelioid tumors. All of them were negative for A103. Our findings suggest that once melanoma is excluded, A103 can aid in the recognition of steroid hormone-producing tumors and may be particularly useful in the diagnosis of adrenocortical carcinoma. The presence of immunoreactivity for A103 practically excludes any other carcinoma that may enter into the differential diagnosis of adrenocortical tumors.

Adrenal incidentalomas. Diagnostic workup of the incidentally discovered adrenal mass

The incidentally discovered adrenal mass is a diagnostic dilemma veterinarians are likely to face with increasing frequency in the coming years. Dogs and cats may be more prone to functional adrenal lesions than are humans. Most adrenal tumors are benign, but a significant number of adrenocortical carcinomas (approximately 12%) and metastatic lesions within the adrenal glands (3% to 34%) do occur. Evaluation for hypertension, hypokalemia, and loss of hypothalamic-pituitary-adrenal responsiveness to a low dose of dexamethasone is appropriate for all patients with adrenal incidentalomas. The value of clinical and historical signs of hormonal overexpression should not be underestimated. More invasive or expensive diagnostic testing should be predicted on suspicions raised by the history and clinical signs. New diagnostic clinicopathologic tests, including plasma CgA and serum DHEAS, should be investigated in veterinary patients. Advanced diagnostic imaging using nuclear scintigraphy and chemical-shift MRI may offer veterinarians sensitive and specific noninvasive tools to consider for the evaluation of these patients. Patients with large masses, tumors with signs of malignancy, or productive adrenal tumors (plus or minus cortisol-producing tumors in which chemical ablation with mitotane can be attempted) should be considered candidates for exploratory surgery.

Transcription factor adrenal 4 binding protein as a marker of adrenocortical malignancy

Adrenal 4 binding protein (Ad4BP) is a transcription factor that regulates the expression of the steroidogenic enzymes and is expressed primarily in steroidogenic cells. We immunolocalized Ad4BP in adrenocortical carcinoma (eight cases) and various malignancies that histologically simulate an adrenocortical carcinoma to evaluate the value of Ad4BP as an immunohistochemical marker of adrenocortical carcinoma. These malignancies examined were renal cell carcinoma (20 cases), hepatocellular carcinoma (10 cases), malignant melanoma (eight cases), ovarian (six cases) and uterine (three cases) clear cell carcinoma, large cell carcinoma of the lung (five cases), and pheochromocytoma (three cases). Nuclear Ad4BP immunoreactivity was observed only in adrenocortical carcinoma cases but not in other tumors examined. Almost all of the adrenocortical carcinoma cells were immunohistochemically positive for Ad4BP including cells associated with bizarre nuclei. These results show that application of Ad4BP immunostain can contribute greatly to the differential diagnosis of adrenocortical carcinoma.