Renal oncocytosis presenting in childhood: a case report

Testosterone- and Cortisol-secreting Oncocytic Adrenocortical Adenoma in the Pediatric Age-group

Oncocytic tumors are epithelial neoplasms that occur in various organs, including adrenal glands. Oncocytic adrenocortical adenomas and carcinomas are uncommon but well-known pathological entities in adults. However, generally oncocytic tumors, particularly in the adrenal glands, are very rare in the pediatric age-group. Most oncocytic adrenal tumors are not functional. We present a rare case of right-sided, functional oncocytic adrenocortical adenoma in a 5-year-old boy, who presented with clinical manifestations of precocious puberty and Cushing syndrome. Laparoscopic adrenalectomy showed a well-defined mass weighing 8.4 g and measuring 3 cm in maximum dimension. Histological examination demonstrated no features suggestive of aggressive biological behavior. The patient showed no evidence of recurrent or metastatic disease and continued to have normal serum hormonal levels 28 months following the surgery. In this report, we discuss the clinicopathological characteristics of this rare pathological entity and briefly review the literature on functional oncocytic adrenal tumors in the pediatric population.

Emerging entities in renal cell neoplasia: thyroid-like follicular renal cell carcinoma and multifocal oncocytoma-like tumours associated with oncocytosis

The list of accepted entities of renal cell neoplasia has burgeoned since the turn of the century through recognition of rare tumour types and the discovery of genetic mutations driving renal neoplasia syndromes. This growth has not finished and in this report we present examples of each of these types which were not included in the 2016 World Health Organization classification of renal neoplasia, but are candidates for inclusion in the next edition of the classification. Thyroid-like follicular renal cell carcinoma is a rare tumour type with a distinctive microscopic appearance resembling follicles of the thyroid gland. Thirty-nine cases have been described and the findings have been reasonably consistent. Oncocytoma-like tumours associated with oncocytosis arise as a result of somatic mutations in the mitochondrial genome. The differential diagnosis is mainly with the renal lesions of the Birt-Hogg-Dubé syndrome, which is the result of germline mutations in the folliculin gene. Patients with oncocytoma-like tumours associated with oncocytosis are at great risk of developing renal failure as the proliferating lesions replace the renal parenchyma. Oncocytoma-like tumours have never been found to metastasise.

Virilizing adrenocortical oncocytoma in a child: a case report

Functioning adrenocortical oncocytomas are extremely rare and most reported patients are 40-60 yr of age. To our knowledge, only 2 cases of functioning adrenocortical oncocytomas have been reported in childhood. We report a case of functioning adrenocortical oncocytoma in a 14-yr-old female child presenting with virilization. She presented with deepening of the voice and excessive hair growth, and elevation of plasma testosterone and dehydroepiandrosterone sulfate. She had an adrenalectomy. The completely resected tumor composed predominantly of oncocytes without atypical mitosis and necrosis. A discussion of this case and a review of the literature on this entity are presented.

[Chromophobe renal cell carcinoma, an exceptional entity in childhood: a case report]

Chromophobe renal cell carcinoma (CRCC) is a rare variant of renal carcinomas arising from the intercalated cells of the distal renal tubule and representing 5% among all renal tumors. Its biological behaviour is variable, less aggresive than clear cell renal carcinoma. Histochemical, ultrastructural and molecular genetic characteristics are different from other renal carcinomas. Age at presentation is about the 6th decade of life. We report an exceptional 10 year-old boy case with a CRCC. Diagnostic and therapeutic aspects for the management of this tumor are reviewed.

Adrenocortical oncocytoma: a case report and review of literature

Oncocytic tumors of the adrenal gland are uncommon. Most of these oncocytomas are benign and nonfunctioning. We report the case of functioning adrenocortical located in the right adrenal gland in a 6-year-old girl who presented with pseudoprecocious puberty and elevation of the estradiol level. She had an adrenalectomy. The tumor was small and composed predominantly of oncocytes. No criteria of malignancy were found. A discussion of this case and a review of the literature on this entity are presented.

Interphase cytogenetic analysis with centromeric probes for chromosomes 1, 2, 6, 10, and 17 in 11 tumors from a patient with bilateral renal oncocytosis

Renal oncocytosis is characterized by the presence of multiple tumors with oncocytic features, often associated with small clusters of tubule-like structures with oncocytic change. The morphologic features of the oncocytic nodules encompass a spectrum of appearances, with patterns typical of renal oncocytoma or classic chromophobe renal cell carcinoma, as well as 'hybrid' tumors with features resembling both oncocytoma and chromophobe renal cell carcinoma. We utilized interphase cytogenetic methods to study 11 tumors from the kidneys of a 45-year-old woman. The tumors included morphologically classical oncocytomas and 'hybrid' tumors with features reminiscent of chromophobe carcinoma. The kidneys also showed foci of oncocytic change in renal tubules. Fluorescence in situ hybridization was performed with centromeric probes for chromosomes 1, 2, 6, 10, and 17 in each of the 11 tumors to determine whether or not there were losses of the chromosomes that are most frequently lost in chromophobe renal cell carcinomas. Neoplastic nuclei from each tumor were evaluated for the number of hybridization signals and scored according to the percentage of nuclei with one, two, and three or more signals. The normal renal parenchyma surrounding the tumors was used as control tissue. All 11 tumors from this patient with renal oncocytosis showed no loss of any of the chromosomes 1, 2, 6, 10, or 17, a pattern identical to that found in normal control tissues. These observations weigh against the concept that hybrid tumors of oncocytosis are closely related to chromophobe renal cell carcinoma.

Chromophobe renal cell carcinoma in a child: case report and review of the literature

Renal cell carcinomas are rare in children but are in the differential diagnosis of renal masses in children age 5 years and older. We present a case of a chromophobe renal cell carcinoma in an 8-year-old boy that arose as a 7-cm (greatest dimension) unilateral renal mass. The tumor had eosinophilic cells, with the typical perinuclear halos and positive staining with Hale's colloidal iron that are seen in this tumor. Although papillary renal cell carcinomas are the most common variant of renal cell carcinoma in children, chromophobe renal cell carcinoma is a rarely reported variant that is not uncommon and has a relatively favorable prognosis in adults.

Hybrid chromophobe renal cell neoplasm

Hybrid renal cell neoplasms (HRCNs) containing areas of tumor cells displaying cytological features of chromophobe renal cell carcinoma (CHRCC) and renal oncocytoma (RO) have been recently described in patients with renal oncocytosis and Birt-Hogg-Dube (BHD) syndrome (autosomal dominant genodermatosis). In this study, we identified cases of sporadic HRCN. We reviewed 425 consecutive renal cell carcinomas (RCC), 18 CHRCC, six HRCN, and 25 RO. Five HRCN were identified, including four from the group of RCC and two from RO. Patient age ranged from 40 to 68 years (mean age: 54 years), and the male:female ratio was 4:1. Tumors measured from 1.8 to 5 cm (mean diameter: 3.0 cm). Tumoral necrosis was not seen. Vascular invasion into medium-sized veins was identified in one HRCN. Chromophobe cells accounted for 20-80% of the tumors. Hale's colloidal stain showed weak to moderate diffuse cytoplasmic staining in scattered cells corresponding to those displaying routine staining features of chromophobe cells. Areas of oncocytic cells in studied tumors and control oncocytomas showed negative or focal cytoplasmic staining usually bordering extra- or intra-cytoplasmic lumina. Immunostaining for cytokeratin 7 and vimentin showed focal immunoreactivity in three cases and negative reactivity in all six cases, respectively. None of the study cases had microscopic RO, as commonly seen in renal oncocytosis, or were associated with BHD syndrome Sporadic HRCN accounted for 1% of RCC. They were of smaller size than RCC and were associated with a favorable prognosis.