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M Venara

Publications and source records attributed to M Venara.

7 recordsLinked to original sources
PubMed2001

Intermittent hyperaldosteronism in a child due to an adrenal adenoma.

UNLABELLED: Aldosterone producing adenoma (APA) is a rare but potentially curable form of paediatric hypertension. We report a case of APA in a 9-year-old boy, suspected due to persistent hypokalaemia. Neither BP nor initial laboratory investigations disclosed the diagnosis and the presence of an APA was suggested by functional tests and radiological findings. Histologically, a cortical tumour was found associated with a marked medullary hyperplasia of both chromaffin and ganglion cells. CONCLUSION: This case reinforces the need for further investigations in patients with misleading clinical and laboratory data.

Adenoma↗
PubMed2001

Sertoli cell proliferations of the infantile testis: an intratubular form of Sertoli cell tumor?

We report on six boys with intratubular Sertoli cell proliferations (ISCPs), studied by routine histologic methods, electron microscopy, and immunohistochemistry of anti-müllerian hormone (AMH), inhibin alpha-subunit, 3beta-hydroxysteroid dehydrogenase (3beta-HSD), proliferative cellular nuclear antigen, and p53, and carefully followed for extended periods with periodic clinical examinations, testicular ultrasonographies, and determinations of serum levels of AMH and inhibin B. Peutz-Jeghers syndrome was found in four of six patients, and gynecomastia occurred in five of six patients. One boy had isosexual pseudoprecocity. ISCPs were observed as multiple foci of seminiferous tubules with large and proliferated Sertoli cells replacing germ cells and limited by the basement membrane. Mitotic figures, atypia, and/or interstitial invasion were not observed. Bilateral ISCPs were the only pathologic finding in three patients (patient nos. 1-3) and were associated with a microscopic tumor that resembled a large-cell calcifying Sertoli cell tumor (LCCSCT) in a fourth patient (patient no. 4). In the two remaining patients (patient nos. 5 and 6) ISCPs and LCCSCT were found in both testes. Ultrastructural examination showed large Sertoli cells, with round nuclei, sparse organelles, and some glycogen. Inhibin alpha-subunit immunolocalization was positive in the five patients in whom it was determined (patient nos. 2-6), AMH was positive in those ISCPs associated with tumors (patient nos. 4-6) and negative in isolated ISCPs (patient nos. 2 and 3); 3beta-HSD and PCNA were variable, and p53 was negative in all ISCPs. Patient nos. 1-4 have been followed for 2-19 years. One of them is currently entering puberty, the other two have already completed puberty and have testes of normal size, and the remaining one is an adult with clinically normal testes and sperm production. None of these patients had evidence of tumor development during follow-up as shown by serial ultrasonographies and serum levels of AMH and inhibin B. Patient nos. 5 and 6 who had bilateral ISCPs and LCCSCT were orchidectomized and evolved for 2-10 years after surgery without tumor recurrence. The prognostic significance of ISCPs, particularly when they are the only pathologic finding in a testicular biopsy, is a matter of controversy. Based on the long normal evolution, we recommend a conservative approach to therapy. The bilateral and multicentric character of ISCPs and their association with Sertoli tumors and Peutz-Jeghers syndrome suggest that they represent either proliferative lesions with tumorigenic potential or the intraepithelial stage in the evolution of some testicular Sertoli cell tumors.

3-Hydroxysteroid Dehydrogenases↗
PubMed2001

Macroorchidism due to autonomous hyperfunction of Sertoli cells and G(s)alpha gene mutation: an unusual expression of McCune-Albright syndrome in a prepubertal boy.

We report an unusual observation of a 3.8-yr-old boy with McCune-Albright syndrome (MAS) associated with abnormal prepubertal testis enlargement and no sexual precocity. Physical examination showed café-au-lait skin lesions, enlarged testes, prepubertal sized penis, and no pubic or axillary hair. Skeletal radiography disclosed fibrous dysplasia. The serum testosterone level was 0.58 nmol/L and remained below 1.4 nmol/L during the 4-yr follow-up. By contrast, serum inhibin B and anti-Mullerian hormone concentrations were abnormally increased up to 255 pg/mL (childhood range, 35--180) and 792 pmol/L (childhood range, 309--566), respectively. The LH response to a GnRH test was in the prepubertal range, whereas the FSH response was blunted. This abnormal hormone concentration profile indicates autonomous hyperfunction of Sertoli cells, with no evidence of Leydig cell activation. Testicular histology showed tubules with marked Sertoli cell hyperplasia and very rare germinal cells, and interstitial tissue containing mesenchymal cells but no mature Leydig cells. DNA sequence analysis from bone and testis tissues detected the known activating mutation in MAS that results in replacement of Arg by His at codon 201 of the G(s)alpha protein. Other endocrine tests showed excessive GH secretion and moderate adrenal androgen hypersecretion. These findings are consistent with the occurrence of an activating mutation of the G(s)alpha gene mainly expressed in Sertoli cells and weakly expressed or absent in Leydig cells. Abnormal prepubertal testicular enlargement extends the clinical spectrum of MAS, suggesting that determination of serum inhibin B and anti-Mullerian hormone should be considered in boys with this syndrome. This observation demonstrates the usefulness of detailed molecular and biological investigations in atypical cases of MAS.

Base Sequence↗
PubMed2000

Anti-Müllerian hormone is a specific marker of sertoli- and granulosa-cell origin in gonadal tumors.

Sex cord stromal tumors are gonadal neoplasms containing Sertoli, granulosa, Leydig, or thecal cells, which originate from cells derived from either the sex cords (Sertoli and granulosa cell tumors) or the specific mesenchymal stroma (Leydig and thecal cell tumors) of the embryonic gonad. Only granulosa and Sertoli cells produce anti-Müllerian hormone (AMH). Our purpose was to investigate whether AMH can be used as a specific marker of human granulosa or Sertoli cell origin in gonadal tumors, to distinguish them from other primary or metastatic neoplasms, using immunohistochemistry. We studied 7 juvenile and 6 adult-type granulosa cell tumors of ovarian localization and 3 extraovarian metastases, 20 other ovarian tumors, 6 testicular Sertoli cell tumors, 2 gonadoblastomas, and 13 extragonadal tumors. Granulosa cell tumors, both juvenile- and adult-type of either ovarian or metastatic localization, showed an heterogeneous pattern of AMH immunoreactivity: Areas containing intensely or weakly AMH-positive cells were intermingled with AMH-negative areas. Although in most cases AMH-positive areas represented a minor proportion of tumor cells, we found a positive reaction in all the cases examined. In testes, although normal prepubertal Sertoli cells were intensely positive, testicular Sertoli cell tumors showed large areas of negative reaction, with few positive cells scattered throughout the tumor. AMH was also reactive in most of the cells of sex-cord origin in gonadoblastomas. No AMH immunoreaction was observed in other gonadal and extragonadal tumors. We conclude that AMH expression is conserved in only a small proportion of tumor cells of granulosa or Sertoli cell origin; however, a positive reaction in a few cells helps to distinguish between granulosa or Sertoli cell tumors or gonadoblastomas and other gonadal tumors of different origin.

Adrenal Cortex Neoplasms↗
PubMed1996

Functional adrenal cortical tumors in pediatric patients: a clinicopathologic and immunohistochemical study of a long term follow-up series.

BACKGROUND: Controversy exists as to which variable is a reliable predictor of clinical outcome of adrenal cortical tumors in children. METHODS: Twenty patients with adrenal cortical tumors were studied. Tumor weight, histologic features, and percentage of proliferating cell nuclear antigen (PCNA/cyclin) in tumor cells were analyzed to determine the best predictor of clinical outcome. RESULTS: Eleven patients had Cushing's syndrome with virilization and 9 had virilization without Cushing's syndrome. The mean age at diagnosis was 7.1 +/- 5.2 years (range, 0.4-15.6 years). Sixteen patients, with good outcomes have been followed for 10.7 +/- 7.8 years (range, 3-23 years). All but two patients had a tumor weight of less than 100 g (185 g and 800 g, respectively) (mean 47.7 g +/- 46.4 g). Two patients with large tumors (weighing 1000 g and 780 g, respectively) had poor outcomes; 1 died 3 months after surgery with metastasis and the other presented with lung metastasis 18 months after surgery. Histologic features did not correlate with clinical outcome. Overall, PCNA stained cells were 6.96 +/- 8.2% (range, 0-32.5%). PCNA values were significantly lower in tumors of patients with good outcomes (P < 0.002). Within all tumors, we found a weak correlation between tumor weight and PCNA (r = 0.51; P < 0.02), but a better correlation was found between tumor weight and PCNA in patients with Cushing's syndrome (r = 0.70; P < 0.01). Patients with Cushing's syndrome had higher PCNA values than those with virilization syndrome (10.3 +/- 9.6% vs. 2.8 +/- 3.3%; P < 0.03). CONCLUSIONS: Our data show that small tumors (less than 100 g) are associated with good outcome; the two patients with the poorest prognosis had Cushing's syndrome and large tumors (more than 100 g). Histologic features are not adequate predictors of outcome and PCNA may be useful in tumors of patients with Cushing's syndrome, but this parameter should not be used alone. Two patients had virilization syndrome, large tumors (185 g and 800 g, respectively), and good outcomes, which contradicts with the concept that these tumors are usually associated with poor prognosis.

Adolescent↗
PubMedDate not supplied

Functional adrenal cortical tumors in childhood: a study of ploidy, p53-protein and nucleolar organizer regions (AgNORs) as prognostic markers.

Prognostic markers in pediatric adrenal cortical tumors are difficult to define. We determined the ploidy, immunostaining of p53-protein and number of nucleolar organizer regions (AgNORs) in 16 such tumors and related them to clinical outcome, tumor weight (TW) and histologic Weiss' criteria. Eleven females and 5 males aged 0.4 to 15.6 years were followed for 8.7 years; 10 presented Cushing's and 6 virilization syndrome. Diploid (n = 4, x TW = 269 g, range: 17-800 g) and near-diploid tumors (n = 3, x TW = 55 g, range: 20-85 g) had good outcome, Weiss' criteria were 0-7, and p53 reactivity was negative in all. Among the aneuploid tumors (n = 9, x TW = 298 g, range: 7-1000 g), 6 had good outcome, 2 presented metastasis and 1 was lost to follow-up; Weiss' criteria were 2-8 and p53 reactivity was positive in 3 tumors (2 of them of malignant evolution). AgNORs number was not different in cases of good or poor outcome (3.65 +/- 1.9 vs 2.83 +/- 1.1). Our findings indicate that diploid and near-diploid cases had always a good outcome regardless of tumor weight. In aneuploid cases, tumor weights < 100 g had good outcome, while those > 750 g had poor prognosis. Malignant tumors were aneuploid and had reactivity to p53-protein. Good outcome in aneuploid tumors < 100 g is probably due to early treatment. The expression of p53-protein appears as a promising marker of poor prognosis. Weiss' criteria and AgNORs were not useful in the present series.

Adolescent↗