Anti-?-inhibin

Renal Cell Carcinoma With Hemangioma-Like Features: Diagnostic Implications and Review of the Literature

Renal cell carcinoma (RCC) with clear cell morphology may show a prominent delicate vascularity. In this article, we report the morphologic and immunohistochemical features of a clear cell papillary RCC mimicking hemangioblastoma and a clear cell RCC mimicking hemangioma. Case 1 showed tubular and papillary growth of clear cells with distinctive areas of capillary proliferation and admixed stromal-like cells resembling a hemangioblastoma. Case 2 consisted of homogeneously delicate microvascular proliferations resembling a capillary hemangioma with scattered inconspicuous clear cells. The clear cells of Case 1 were PAX8(+), CK7(diffuse+), CA9(diffuse+, cup-shaped), and inhibin A(−). The hemangioblastoma-like areas were PAX8(+), CK7(−), CA9(diffuse+), and inhibin A(diffuse+). Case 2 showed PAX8(+), CK7(−), and CA9(diffuse+). They can be diagnostically challenging, and it is important to recognize that a pure hemangioma or hemangioblastoma of the kidneys is very rare, and that RCCs with clear cell morphology rarely exhibit hemangioma-like characteristics.

Laparoscopic Treatment of Adrenal Tumors: A Single-Center Experience with 58 Patients

Background. The aim of this study is to discuss the laparoscopic approach and assess the immunohistochemical expression profiles of synaptophysin, Ki-67, and inhibin and patient outcomes in adrenal masses through a series of cases treated at our institution. Method. The study was conducted on 58 patients who were diagnosed with adrenal masses. All cases were operated on laparoscopically for adrenal masses. Results. Both inhibin and synaptophysin were found positive in 45 patients (77,6%). Ki-67 was negative in 11 patients, whereas it was found positive in 42 with a rate of 1%. The size of the masses ranged from 1 up to 9 cm (mean 4,3 ± 1,5). Urine hormone excretion was measured within normal ranges in 47 out of 58 patients (81%). Most of the diagnosed patients were harboring Cortical Adenoma (n: 38; 65,5%). All of the masses were successfully resected without complication except 3 patients. Because of complications of bleeding, the operation was converted to open surgery for 2 patients. Conclusion. Morbidity, mortality, and healing were comparable, regardless of tumor size, yet involvement in both laparoscopic and adrenal surgery was required. Our results suggested that laparoscopic adrenalectomy should replace open surgery as the standard treatment for most adrenal masses.

Diagnostic and prognostic features in adrenocortical carcinoma: a single institution case series and review of the literature

Background

Adrenocortical carcinoma is a rare cancer, with an incidence in the literature of 0.5 to 2 cases per million population per year. Adult adrenocortical carcinoma has a poor prognosis, underscoring the importance of identifying diagnostic and prognostic markers.

Methods

We searched our laboratory database for all cases in the past 15 years with a diagnosis of adrenocortical carcinoma. The original slides were then reviewed for their histopathological features. A representative paraffin block was subjected to further immunohistochemical staining for Ki-67, inhibin, steroidogenic factor-1 (SF-1), p53, and Β-catenin. These slides were scored by the study pathologist who was blinded to all clinicopathological data. In addition, a comprehensive review of the relevant English literature in the past 15 years was conducted.

Results

Eight cases were identified, including two adrenal sarcomatoid carcinomas. Seven of the eight cases had a disrupted reticulin network. Six of the eight tumors had >10% Ki-67 expression. Five of the eight tumors had >10% p53 expression. Positive inhibin immunohistochemical staining was seen in three of the eight tumors, and positive SF-1 staining was seen in five of the seven stained tumors. Abnormal Β-catenin intracellular accumulation was noted in four of the eight tumors. The two tumors in our series with sarcomatoid histology did not stain positively for SF-1 or inhibin.

Conclusions

Eight cases of adrenocortical carcinoma, including two with sarcomatoid features are presented. The two sarcomatoid adrenocortical carcinomas in our series did not stain for SF-1 which suggests a possible de novo pathway of tumorigenesis for this rare variant. The reticulin staining method was a useful tool for rapid differentiation of adrenocortical adenomas and carcinomas. Diffuse p53 staining showed a trend for positive correlation with increased Ki-67 expression. Inhibin staining was inconsistently expressed in our cases of adrenocortical carcinoma. In conclusion, as adrenocortical carcinoma is a rare disease, we recommend future multicenter studies with appropriate sample sizes to further evaluate the efficacy of these diagnostic and prognostic markers.

Assessing Biological Aggression in Adrenocortical Neoplasia

Pathologists are highly skilled at the evaluation of adrenal neoplasms. Occasional adrenocortical tumors can be diagnostically challenging and supplementary tools can assist in these cases. Histologic and molecular studies support a model that includes 2 broad classes of adrenocortical carcinoma with distinct somatic genetic alterations and clinical outcomes. Pathologists should endeavor to grade adrenocortical carcinomas to assign each case into one of these 2 classes. Mitotic grading by mitotic counting and Ki-67 immunohistochemistry represent the most practicable and informative methods currently available.

Cytodiagnosis of myxoid adrenocortical carcinoma and role of immunocytochemistry to differentiate it from renal cell carcinoma

Adrenocortical carcinoma (ACC) is a rare malignancy and cytodiagnosis of this tumor is not routinely encountered by a cytopathologist. Here, we report a case of ACC initially diagnosed by computed tomography (CT)-guided fine needle aspiration cytology (FNAC) with the help of immunocytochemistry. A 48-year-old lady presented with flank pain and abdominal mass for the last 6 months. A CT scan of her abdomen revealed a large mass arising from the upper part of the left kidney. CT-guided FNAC was performed. Cytologic smears showed pleomorphic large cells arranged discretely and in small aggregates against a myxoid background. The cells had a high nucleocytoplasmic ratio, anisonucleosis and conspicuous nucleoli. Based on cytomorphology, differential diagnoses of ACC and renal cell carcinoma (RCC) were made. On immunocytochemistry, the tumor cells were synaptophysin, inhibin, vimentin and Melan-A positive but cytokeratin and epithelial membrane antigen negative. Thus, a cytodiagnosis of myxoid ACC was made and histopathologic examination was suggested. Subsequent histologic examination and immunohistochemistry proved the case to be myxoid ACC.

Endoscopic ultrasound-guided fine-needle aspiration diagnosis of clear-cell pancreatic endocrine neoplasm in a patient with von Hippel-Lindau disease: a case report

The cytologic findings of a clear-cell pancreatic endocrine neoplasm (PEN) diagnosed by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) occurring in a 29-year-old man with von Hippel-Lindau (VHL) syndrome are described. Imaging studies showed multiple pancreatic masses and cysts, a single liver lesion, and pulmonary and renal cysts. Cytologic features of this clear-cell PEN included the presence of large sheets and rounded clusters of polygonal neoplastic cells with relatively abundant cytoplasm containing numerous, small, sharply-demarcated vacuoles that occasionally indented nuclei and gave the cells a "frothy" appearance. Mild anisonucleosis was present and nucleoli were visible. Rare single cells and stripped nuclei were seen. Small vessels transgressed tumor cell sheets. These cytologic findings are distinct from those of typical endocrine neoplasms, and bear resemblance to the cytologic features of renal cell carcinoma metastatic to the pancreas. To the best of our knowledge, this is the first detailed report of the EUS-FNA cytologic findings of a clear-cell PEN associated with VHL syndrome. We believe that the distinctive and characteristic cytologic features, together with immunohistochemical studies, can allow a preoperative cytologic diagnosis of this highly unusual pancreatic lesion and avoid possible confusion with other clear-cell neoplasms in the pancreas, particularly metastatic renal cell carcinoma.

Intrarenal ectopic adrenal tissue and renal-adrenal fusion: a report of nine cases

Intrarenal ectopic adrenal tissue and renal-adrenal fusion are rare findings in the adult population. We reviewed seven cases of intrarenal adrenal tissue and two cases of renal-adrenal fusion. Patients ranged in age from 35 to 75 years (mean 55). Ectopic adrenal tissue was identified at the superior pole of the kidney in all but one case, which was located in the mid-portion of the kidney. Ectopic adrenal tissue varied in its growth from subcapsular lesions that were plaque-like (n=3), wedge-shaped (n=2), or spherical (n=1) to irregular nests deep in the renal parenchyma (n=1). In all nine cases, the adherent and intrarenal adrenal tissue was composed of adrenal cortical tissue, with no adrenal medullary tissue present. In six cases, adrenal tissue focally extended into renal parenchyma in an infiltrative manner. Of the nine cases, two were diagnostic problems for the contributing pathologists. In one case, intrarenal adrenal tissue mimicked low-grade clear cell renal cell carcinoma. In another case, an adrenocortical adenoma adherent to the kidney resembled renal invasion by adrenocortical carcinoma. This study summarizes key morphological features of intrarenal ectopic adrenal tissue and renal-adrenal fusion along with histological pitfalls and its differential diagnoses.

Discerning malignancy in resected adrenocotical tumors

BACKGROUND

The number of adrenocortical tumors discovered incidentally has recently increased owing to the advent of imaging techniques. The most important diagnostic point in evaluation of resected specimens of these tumors is to discern malignancy to determine postoperative management of the patients.

OBJECTIVE/METHODS

To determine what the effective methods of discerning malignancy in resected specimens of adrenocortical tumors are at this juncture. To provide relevant and practical information pertinent to those involved in the management of patients with adrenocortical tumors.

CONCLUSION

Careful macroscopic evaluation, including the selection of the specimens submitted and application of the criteria of Weiss for histological diagnosis, is still considered the 'gold standard' for diagnosis of adrenocortical carcinoma. However, it is important to recognize its limitations in the diagnosis of adrenocortical oncocytoma and pediatric adrenocortical tumors. The auxiliary methods that may be of clinical relevance at this juncture include the analysis of the Ki67/MIB-1 labeling index and IGF-II expression in the tumors.

Utility of antiphosphorylated H2AX antibody (gamma-H2AX) in diagnosing metastatic renal cell carcinoma

The differential diagnosis of metastatic renal cell carcinoma (RCC) includes, although is not limited to, hepatocellular carcinoma (HCC) and adrenocortical carcinoma (ACC) due to overlapping morphology. Immunohistochemical markers, including RCC marker (RCC-Ma) have been employed with varying success in the differential diagnosis of RCC. Our preliminary tissue microarray study demonstrated that gamma-H2AX, an antibody that specifically reacts with phosphorylated histone H2AX, stained many primary RCC strongly and did not stain HCC or ACC, prompting us to evaluate its utility in these tumors and to compare it with RCC-Ma. Seventy-one cases of metastatic RCC, 18 HCC, and 21 ACC were stained with gamma-H2AX and RCC-Ma and the sensitivity and specificity of each marker was compared. RCC-Ma demonstrated a membranous pattern of staining in 70% of RCC cases (50/71), and none of the ACC or HCC (100% specificity for RCC). Nuclear staining by gamma-H2AX had a similar sensitivity of 70% for RCC but a lower specificity of 77%, as it was seen in 1 of 18 HCC (5%) and 8 of 21 (38%)ACC. In metastatic RCC, 83% (39/47) of tumors with a higher nuclear grade stained with gamma-H2AX, compared with 46% (11/24) of low nuclear grade (equivalent of Fuhrman 2 and lower) tumors. RCC-Ma had a similar rate of staining in low and high-grade tumors, 75% (18/24) and 68% (32/47), respectively. More importantly, of RCCs that were negative for RCC-Ma, 14 of 21 (67%) were positive for gamma-H2AX. The results suggest gamma-H2AX is a useful adjunct in diagnosis of metastatic RCC when RCC-Ma is negative and in higher grade RCC, which are often a diagnostic challenge. A nuclear pattern of staining of gamma-H2AX has a comparable sensitivity with RCC-Ma, and the interpretation is easier and more reliable. RCC-Ma is 100% specific for RCC, but only when a membranous pattern of staining is interpreted as positive.

Expression of Renal Cell Carcinoma Antigen (RCC) in Renal Epithelial and Nonrenal Tumors

Antibody to renal cell carcinoma (RCC) antigen, a normal human proximal brush border antigen, has recently become commercially available and reported to be highly specific and a relatively sensitive marker for RCC. Of the nonrenal tumors occasional carcinomas have been reported to express RCC, notably breast carcinoma. Using tissue microarrays, we investigated the use of RCC on a large number of renal epithelial neoplasms (RENs) and nonrenal tumors, especially those potentially confused with REN. Three tissue microarrays containing 241 REN samples, 192 samples of a wide variety of neoplasms and 170 adrenal tumor samples, respectively, were stained with RCC monoclonal antibody. RCC expression was scored for staining intensity and percentage expression. Out of 241 REN, 173 were positive for RCC (sensitivity 72%): clear cell 72%, papillary 95%, chromophobe 91%, unclassified 85%, oncocytoma 75%, sarcomatoid 20%, and metastatic RCC 40%. The overall immunostaining intensity was consistently much higher in papillary and clear cell RCC than in other tumors. Seventy-six out of 362 nonrenal tumor samples demonstrated either focal or diffuse expression for RCC (specificity 79%). These included: adrenocortical neoplasms 37/170 (22%), colonic 11/29 (37.5%), breast 9/27 (33%), prostate 5/18 (27.7%), ovary 2/17 (11.7%), melanoma 3/18 (16.6%), lung 3/21 (14.2%), and parathyroid 3/3 (100%). RCC expression was seen equally among adrenal adenoma and carcinoma group. Eight out of 28 (28.5%) normal adrenal cores also stained for RCC. RCC is a relatively useful marker in the differential diagnosis of REN only if used in a panel with other positive and negative markers. RCC does not reliably differentiate REN, especially classic clear cell type, from adrenocortical neoplasms, which are frequently confused due to close anatomic proximity and similar morphology. RCC also does not reliably differentiate subtypes of renal epithelial neoplasms.

New immunohistochemical markers in the evaluation of central nervous system tumors: a review of 7 selected adult and pediatric brain tumors

CONTEXT

Immunohistochemistry (IHC) has become an important tool in the diagnosis of brain tumors.

OBJECTIVE

To review the latest advances in IHC in the diagnostic neuro-oncologic pathology.

DATA SOURCES

Original research and review articles and the authors' personal experiences.

DATA SYNTHESIS

We review the features of new, useful or potentially applicable marker antibodies as well as the new uses of already established antibodies in the area of diagnostic neuro-oncologic pathology, focusing on the use of IHC for differential diagnosis and prognosis. We discuss (1) placental alkaline phosphatase, c-Kit, and OCT4 for germinoma, (2) alpha-inhibin and D2-40 for capillary hemangioblastoma, (3) phosphohistone-H3 (PHH3), MIB-1/Ki-67, and claudin-1 for meningioma, (4) PHH3, MIB-1/Ki-67, and p53 for astrocytoma, (5) synaptophysin, microtubule-associated protein 2, neurofilament protein, and neuronal nuclei for medulloblastoma, (6) INI1 for atypical teratoid/rhabdoid tumor, and (7) epithelial membrane antigen for ependymoma. All the markers presented here are used mainly for supporting or confirming the diagnosis, with the exception of the proliferation markers (MIB-1/Ki-67 and PHH3), which are primarily used to support grading and are reportedly associated with prognosis in certain categories of brain tumors.

CONCLUSIONS

Although conventional hematoxylin-eosin staining is the mainstay for pathologic diagnosis, IHC has played a major role in differential diagnosis and in improving diagnostic accuracy not only in general surgical pathology but also in neuro-oncologic pathology. The judicious use of a panel of selected immunostains is unquestionably helpful in diagnostically challenging cases. In addition, IHC is also of great help in predicting the prognosis for certain brain tumors.

Comparison of immunomarkers for the identification of adrenocortical cells in cytology specimens

We studied the immunoreactivity of three antibodies--A103, calretinin, and inhibin alpha in destained Papanicolaou (Pap) smears and cell-blocks of 40 fine-needle aspiration biopsy cases of adrenocortical lesions (35 cases of hyperplasia/adenoma and 5 cases of carcinoma). Five cases of carcinoma (4) and melanoma (1) metastases to the adrenal gland and five cases of renal-cell carcinoma were also included for comparison. In benign adrenocortical lesions, A103 staining was noted in 82% of the destained Pap smears and in 92% of cell-blocks. In malignant adrenocortical lesions, A103 staining was noted in 50% of the destained Pap smears and in 80% of cell-blocks. In comparison, calretinin staining was noted in 6% and 50% of destained smears and in 78% and 60% of the cell-blocks of benign and malignant adrenocortical lesions. Inhibin alpha was not positive in any of the smears and showed the lowest level of positivity in the cell-block sections, namely in 11% of the benign lesions and 25% of the malignant lesions. The sensitivity of A103 was 90% on cell-blocks and 74% on smears, that of calretinin 75% on cell-blocks and 11% on smears, and that of inhibin alpha, 13% on cell-blocks alone. The specificity of A103 was lower than the other two makers, 90% vs. 100% because of positivity in metastatic melanoma in the adrenal gland. Our data show A103 to be the immunomarker with the highest sensitivity for identifying cells of adrenocortical origin in destained Pap's smears and cell-block sections with, however, a lower specificity when compared with calretinin and inhibin alpha. Calretinin is comparable in sensitivity with A103 on cell-block sections alone and not on smears. The results of this study suggest that if metastatic melanoma in adrenal gland is not a consideration then A103 is the marker of choice for identifying cells of adrenocortical origin in the limited material available for diagnostic purposes in cytology specimens.

Immunoreactivity of CD10 and inhibin alpha in differentiating hemangioblastoma of central nervous system from metastatic clear cell renal cell carcinoma

The differential diagnosis between hemangioblastoma of the central nervous system and metastatic clear cell renal cell carcinoma can be problematic, because they may share striking morphologic similarities. Since CD10 is expressed in clear cell renal cell carcinoma, while inhibin alpha is expressed in hemangioblastoma, we used CD10 and inhibin alpha (inhibin A) to study their possible use in the distinction of these two entities. A total of 22 cases of cerebellar hemangioblastoma, five cases of metastatic clear cell renal cell carcinoma to the central nervous system, and 16 primary cases of clear cell renal cell carcinoma were studied with immunohistochemical staining of both CD10 and inhibin A. All 22 cases of hemangioblastoma were immunonegative for CD10 in the stromal cells. In contrast, all five cases of metastatic clear cell renal cell carcinoma and 16 cases of primary clear cell renal cell carcinoma showed positive CD10 membranous staining. In all, 20 cases of hemangioblastoma (20/22, 91%) expressed inhibin A in the stromal cells. Two cases of primary clear cell renal cell carcinoma (2/16, 13%) and three cases of metastatic clear cell renal cell carcinoma (3/5, 60%) showed immunopositivity for inhibin A. In conclusion, in addition to the immunostaining of inhibin A, CD10 is a superior marker for distinguishing between a hemangioblastoma and a metastatic clear cell renal cell carcinoma.

Sampling of the adrenal glands by endoscopic ultrasound-guided fine-needle aspiration

Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) has proven to be a valuable modality for the primary diagnosis and staging of gastrointestinal, and perigastrointestinal malignancy. Aside from assessing thoracic and abdominal lymph nodes and the liver for metastases, EUS can assess and sample the adrenal glands, which are frequently involved by metastatic disease, but can also harbor benign primary neoplasms. The cytology files at our institution were reviewed for all cases of EUS-guided FNA of the adrenal glands. Clinical histories, sonographic findings, and cytologic findings of all cases were reviewed. Results were compared with overall EUS-guided FNA performance and the performance of non-EUS-guided FNA of the adrenal. The utility of cell block immunohistochemistry (IHC) in these cases was reviewed. Between 1/1/00 and 5/15/04 there were 24 cases of EUS-guided FNA of the adrenal gland from 22 different patients (13 men; 9 women) at our institution. This represented 1.4% of overall EUS-guided FNA and 77% of adrenal gland FNA. Patient ages ranged from 37 to 86 yr (mean 69 +/- 11 yr). Most patients had other cancers or mass lesions and were being staged at the time of the procedure (19 of 22). Almost all FNAs were of the left adrenal gland (23 of 24). Lesion size ranged from 0.9 to 7.9 cm (mean 2.5 +/- 1.6 cm). Diagnostic material was present in all cases when compared with an overall EUS-guided FNA diagnostic rate of 88%. Material for cell block was present in 21 cases, and IHC was used in 3 cases. Final diagnoses were as follows: cortical tissue consistent with cortical adenoma (19), metastatic adenocarcinoma (3), pheochromocytoma (1), and adrenal cortical carcinoma (1). EUS-guided FNA of the adrenal gland is primarily used in the staging of other malignancies when lesions of the left adrenal are recognized sonographically. Diagnostic tissue is easily obtained, including material for cell block IHC, which allows definitive diagnosis in cases that present difficult differential diagnoses.

Endoscopic ultrasound-guided fine-needle aspiration biopsy of the adrenal glands: analysis of 24 patients

BACKGROUND

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsy allows the detailed imaging and FNA not only of both intramural and extramural structures and lesions of the gastrointestinal (GI) tract but also of various intraabdominal organs. Thus, EUS-FNA biopsy offers a novel opportunity to evaluate and obtain cytology samples from adrenal gland lesions. The objective of the current study was to determine the utility of EUS-FNA in the diagnosis of adrenal lesions.

METHODS

The authors conducted a prospective evaluation of 24 consecutive EUS-FNA biopsy specimens obtained from patients with adrenal lesions. An attending cytopathologist was present on site to assess specimen adequacy and to provide rapid interpretation of air-dried material that had been stained with Diff-Quik (Baxter Scientific Products, McGraw Park, IL). Additional samples were obtained for ThinPrep (Cytyc Corporation, Boxborough, MA) preparation, and cell blocks subsequently were prepared. Appropriate immunohistochemical staining was performed as indicated. The cytologic diagnosis was then analyzed for correlations with the final diagnosis, which was based on relevant correlative cytologic or histologic examination of biopsied/resected pathology materials and/or final clinical follow-up.

RESULTS

In total, 24 EUS-FNA biopsy specimens (from 18 males and 6 females) were obtained from adrenal glands. The mean patient age was 62.2 years (range, 48-81 years). Adequate cellularity was noted in all 24 samples. Seven of 24 samples (29%) were reported to be positive for carcinoma. All samples that were diagnosed as metastatic carcinoma were confirmed on subsequent follow-up. EUS-FNA performed simultaneously with adrenal gland aspiration either from the primary site (n = 1) or from metastases to lymph nodes (n = 3) supported diagnoses of metastatic carcinoma. Six of seven samples were metastatic from the lung, and one specimen was a direct extension of a transitional renal cell carcinoma. EUS-FNA biopsy of the right adrenal gland in one patient revealed myelolipoma. In 16 patients, benign adrenal gland cells were noted on EUS-FNA biopsy specimens from enlarged adrenal glands. In 5 samples (31%), signs of adenoma were evident. Morphology alone could not distinguish between adrenal adenoma and adrenal hyperplasia. No significant complications were reported after EUS-FNA biopsy of adrenal glands.

CONCLUSIONS

EUS-FNA biopsy is a highly specific and safe technique for confirming the diagnosis of carcinoma metastatic to the adrenal glands. Along with cytologic evaluation, EUS imaging is needed to support the diagnosis of adrenal adenoma.

Serous cystic neoplasms of the pancreas: an immunohistochemical analysis revealing alpha-inhibin, neuron-specific enolase, and MUC6 as new markers

Serous cystic neoplasms (SCNs) of the pancreas include serous microcystic adenoma (SMA), serous oligocystic ill-demarcated adenoma (SOIA), solid serous adenoma (SSA), von Hippel-Lindau-associated cystic neoplasm (VHL-CN), and serous cystadenocarcinoma (SCC). These neoplasms are histologically similar but differ in their localization, gross appearance, gender distribution, and biology. A centroacinar origin is assumed but has not been proven. To clarify whether the various subtypes of SCN may be distinguished from each other by marker profiles that might also provide evidence of their origin, the immunoprofiles of 38 SCNs (21 SMAs, 13 SOIAs, 2 VHL-CNs, 1 SSA, and 1 SCC) were defined by applying antibodies against cytoskeletal, neuroendocrine, hormone receptor, and mucin markers. In addition, we examined the expression of calretinin and alpha-inhibin. The various types of SCN showed a very similar immunoprofile, characterized by positivity for cytokeratins and neuron-specific enolase and negativity for vimentin and synaptophysin. Further markers that were commonly expressed in SCNs were alpha-inhibin (SMAs: 76%, SOIAs: 92%, VHL-CNs: 100%), MUC6 (SMAs: 60%, SOIAs: 85%, VHL-CNs: 100%), and MUC1 (SMAs: 24%, SOIAs: 38%, VHL-CNs: 50%). Western blot analysis in one SMA revealed a distinct band that stained with neuron-specific enolase antiserum. Alpha-inhibin was only expressed in 4 of 11 acinar cell carcinomas and not in five ductal adenocarcinomas, five neuroendocrine tumors, one mixed ductal-endocrine carcinoma, and one acinar cell cystadenoma of the pancreas. These results suggest that, despite their biologic differences, the various types of SCNs are composed of the same (or a very similar) cell type and may therefore have a common direction of differentiation. This notion is further supported by the finding that neuron-specific enolase, alpha-inhibin, and MUC6, which may be regarded as new markers for this pancreatic tumor type, were also expressed in most SCNs. Because a number of SCNs share MUC1 and MUC6 expression with the pancreatic centroacinar cells, the possibility of a histogenetic relationship has to be considered.

Metastatic ovarian Sertoli-cell tumor: FNA findings with immunohistochemistry

A malignant Sertoli cell tumor of the ovary is a rare sex-cord stromal derived neoplasm. Sertoli cell tumors account for approximately 4% of Sertoli-stromal cell tumors (Hsu et al., J Histochem Cytochem 1981;29:577-580). The diagnosis of this entity by fine-needle aspiration and needle core biopsy can be difficult when the differential also includes a metastatic renal cell carcinoma, due to the overlap of both cytological and histological features. Here, we show that immunohistochemical staining on cytological material including alpha-inhibin can be used to differentiate between these two malignant tumors.

Inhibin alpha distinguishes hemangioblastoma from clear cell renal cell carcinoma

Inhibin alpha subunit (inhibin A) expression in hemangioblastomas has not been previously reported in the literature. We analyzed the expression of inhibin A in 25 hemangioblastomas from 22 patients. Eleven cases were from 8 patients with von Hippel-Lindau disease, and these tumors were multicentric and/or recurrent. The remaining 14 cases from 14 patients were sporadic. The male-to-female ratio was 8:3, and the age at presentation ranged from 19 to 78 years (mean 35 years; median 45 years). Eighteen tumors were located in the cerebellum/posterior fossa, 1 in the medulla, 1 in the occipital lobe, and 5 in the spinal cord. Four metastatic renal cell carcinomas in brain, 10 renal cell carcinomas from 8 patients with von Hippel-Lindau disease, and 5 sporadic clear cell renal cell carcinomas were also included. Two patients with von Hippel-Lindau disease had both renal cell carcinoma and hemangioblastoma. The stromal cells of all 25 cases of hemangioblastoma expressed inhibin A. Strong, moderate, and weak cytoplasmic immunoreactivity was noted in 17, 5, and 3 cases, respectively. In contrast, none of the 19 renal cell carcinomas, primary as well as metastatic, expressed inhibin A. There was no difference in the inhibin A staining pattern between the sporadic hemangioblastoma and those associated with VHL. These findings demonstrate inhibin A to be a useful marker in distinguishing hemangioblastoma from metastatic clear cell renal cell carcinoma. While the diagnostic importance is evident, the pathophysiology of inhibin A expression by the stromal cells of hemangioblastoma remains unknown and further investigation is required.

Activins and inhibins in endocrine and other tumors

Inhibin and activin are members of the TGF beta superfamily of growth and differentiation factors. They were first identified as gonadal-derived regulators of pituitary FSH and were subsequently assigned multiple actions in a wide range of tissues. More recently, the inhibin alpha subunit was considered as a tumor suppressor based on functional studies employing transgenic mouse models. This review evaluates the functional and molecular evidence that the inhibin alpha subunit is a tumor suppressor in endocrine cancers. The evaluation highlights the discrepant results from the human and mouse studies, as well as the differences between endocrine tumor types. In addition, we examine the evidence that the activin-signaling pathway is tumor suppressive and identify organ-specific differences in the actions and putative roles of this pathway in endocrine tumors. In summary, there is a considerable body of evidence to support the role of inhibins and activins in endocrine-related tumors. Future studies will define the mechanisms by which inhibins and activins contribute to the process of initiation, promotion, or progression of endocrine-related cancers.

Fine-needle aspiration cytology of adrenal masses in noncancer patients: clinicoradiologic and histologic correlations in functioning and nonfunctioning tumors

BACKGROUND

Image-guided, fine-needle aspiration (FNA) cytology is performed currently in patients with malignant disease who have suspected adrenal metastases. The objective of this study was to evaluate the usefulness and safety of FNA cytology in patients with incidental adrenal masses and functioning tumors.

METHODS

Computed tomography (CT)-guided or ultrasound-guided aspirates using 21-23-gauge needles were performed successfully in 70 patients with functioning (n = 38 patients) and nonfunctioning (n = 32 patients) adrenal masses (median size, 4 cm; range, 3-12 cm) that were detected previously by CT scans.

RESULTS

Definitive histology was available in 68 patients (97.1%), showing 53 benign tumors (77.9%), 11 primitive malignant tumors (16.2%), and 4 unsuspected adrenal metastases (5.9%) in patients with unknown primary tumors. In two patients with aspirate reports that ruled out malignancy, the mass was unchanged on CT scan follow-up; thus, they were considered benign lesions. The benign masses were significantly smaller (P < 0.01), although seven malignant tumors (46.7%) measured 3-4 cm in greatest dimension, and eight benign lesions (14.5%) measured 5-6 cm in greatest dimension. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 66.7%, 96.4%, 83.3%, 91.4%, and 90.0%, respectively, for CT scan and 93.3%, 100%, 100%, 98.2%, and 98.6%, respectively, for FNA cytology. The morbidity rate of image-guided FNA cytology was 4.3% (two patients with self-limited, asymptomatic pneumothorax and one patient with spontaneously resolved adrenal hematoma).

CONCLUSIONS

Adrenal FNA cytology represents a safe and specific procedure for evaluating patients with adrenal masses measuring > 2 cm in greatest dimension. FNA is able to reveal malignancies and unsuspected pheochromocytomas and should be performed in all patients with adrenal tumors whenever requested for surgical planning.

Expression of inhibin-alpha by granular cell tumors of the gallbladder and extrahepatic bile ducts

This is the first report of inhibin-alpha expression in granular cell tumors. A Medline search of the literature revealed no case reports of granular cell tumors in any location of the body being tested for inhibin-alpha immunohistochemically, by enzyme-linked immunosorbent assay, by radioimmunoassay, or by immunoprecipitation. Seventeen cases of previously diagnosed granular cell tumors of the gallbladder and extrahepatic bile ducts with hematoxylin and eosin-stained sections, and S-100 protein immunostain were retrieved from the archives of the Armed Forces Institute of Pathology. All cases were reviewed for diagnostic accuracy and then immunostained for inhibin-alpha (with endogenous biotin blocking). All 17 (100%) cases were diffusely positive for inhibin-alpha immunostain. Previous studies of inhibin-alpha-positive lesions reported in the literature include sex cord stromal tumors (granulosa cell tumors, luteinized thecomas, Leydig cell tumors), placental and gestational trophoblastic lesions, and adrenal cortical tumors. This study adds the granular cell tumor to the list of inhibin-positive lesions and should prove helpful in differential diagnosis of these lesions.

Immunoexpression of inhibin alpha-subunit in adrenal neoplasms

Inhibin normally is produced by ovarian granulosa cells and testicular Sertoli cells. Extragonadal inhibin expression also has been detected in the placenta, pituitary gland, and liver. It may be difficult to make a distinction between adrenal cortical tumors, pheochromocytoma, and metastatic carcinomas including renal cell and hepatocellular carcinoma. Immunohistochemical expression of inhibin alpha-subunit was evaluated to determine whether any usefulness of immunostaining could be found for inhibin alpha-subunit in the differential diagnosis of adrenal glandular lesions. The authors performed immunostaining against inhibin alpha-subunit on 5 cases of normal adrenal gland, 1 case of adrenal cortical hyperplasia, 25 cases of adrenal cortical adenoma, 6 cases of adrenal cortical carcinoma, 21 cases of pheochromocytoma, 8 cases of metastatic carcinoma, and 10 cases of primary renal cell carcinoma. Normal adrenal gland showed a strong immunoreactivity against inhibin alpha-subunit, especially in the inner layer of the adrenal cortex, representing the zona reticularis, but adrenal medulla was negative for inhibin alpha-subunit. Adrenal cortical hyperplasia associated with Cushing's syndrome showed a strong, diffuse immunoreactivity for inhibin alpha-subunit. Immunoreactivity against the inhibin alpha-subunit was identified in all cases of adrenal cortical adenoma and carcinoma, especially in the adrenal cortical neoplasm with Cushing's syndrome, which showed a strong reactivity. However, immunoreactivity was absent in two metastatic carcinomas from the liver and colon and most of the pheochromocytomas, except three cases with weak focal positivity for inhibin alpha-subunit. Four cases of metastatic renal cell carcinoma and 10 cases of primary renal cell carcinoma revealed no immunoreactivity. Metastatic adenocarcinoma from the prostate showed a weak immunoreactivity for inhibin alpha-subunit. Metastatic hepatoblastoma was negative against inhibin alpha-subunit with endogenous biotin blocking. Immunoexpression for inhibin alpha-subunit is useful for making distinction between adrenal cortical tumors, pheochromocytoma, and metastatic carcinoma. Inhibin alpha-subunit may be valuable as part of a diagnostic immunohistochemical panel in adrenal glandular lesions.

Differentiated corticosteroid production and regeneration after selective transplantation of cultured and noncultured adrenocortical cells in the adrenalectomized rat

Syngeneic transplantation of adrenocytes was investigated in Lewis rats in regard to differentiated hormone secretion and cortex regeneration after bilateral adrenalectomy as an alternative to steroid substitution.

METHODS

Purified cell suspensions of glomerulosa (density 1.061 +/- 0.001 g/ml) and fasciculata (density 1.034 +/- 0.003 g/ml) cells were obtained by density gradient separation and were transplanted under the kidney capsule either immediately or after a 29-day culture period. Animals were killed after transplantation of cultured glomerulosa (CG-Tx) or cultured fasciculata cells (CF-Tx), noncultured glomerulosa cells (G-Tx) or non-cultured fasciculata cells (F-Tx), or both cell types (GF-Tx) for morphological studies after 30, 120, and 360 days. Plasma samples were drawn for measurement of corticosterone and aldosterone as well as 24 hr-urine for sodium and potassium levels at day 3, 30, 120, and 360 after transplantation.

RESULTS

In primary culture fasciculata cell number remained stationary although glomerulosa cell number increased to almost 10-fold. Vital cortex cells were demonstrated in each explanted graft by histochemistry but only group G-Tx, CG-Tx, and GF-Tx (purified cell suspensions of zona glomerulosa and fasciculata) showed neocortex-like structures. We found plasma (urine) corticosterone to decrease from preoperatively 256-304 ng/ml (226-239 ng/day) in untreated animals to levels about half as high 3 days after transplantation, increasing to normal values in all study groups 30 days after treatment (data given as range). Plasma aldosterone concentrations, 150-180 pg/ml in untreated rats, decreased to nondetectable levels for 1 week after bilateral adrenalectomy. At day 30 group GF-Tx, G-Tx, and CG-Tx showed comparable aldosterone plasma concentrations (104-122 pg/ml); however, levels in F-Tx and CF-Tx were 19-49 pg/ml, and did not increase significantly within the observation period.

CONCLUSIONS

Cells derived from the zona glomerulosa maintain viability, produce both aldosterone and corticosterone, and regenerate a neocortex with cells that histologically resemble both zona glomerulosa and fasciculata cells. They are therefore suitable for adrenocortical transplantation. In contrast, cells derived from the zona fasciculata maintain viability, but do not regenerate zona glomerulosa and do not produce aldosterone. These results suggest that the cell migration model, in which zona glomerulosa cells can acquire the phenotype of zona fasciculata cells as they can migrate centripetally, is more likely the correct explanation of adrenocortical zonation.