Clonal trisomy 4 cells detected in the ossifying renal tumor of infancy: study of 3 cases

Ossifying renal tumor of infancy: A case report

Ossifying Renal Tumor of Infancy (ORTI) represents an extremely rare and benign renal neoplasm, with limited cases published in the literature. Predominantly characterized by painless and intermittent gross hematuria, the diagnostic evaluation is effectively facilitated through ultrasound, computed tomography, and magnetic resonance imaging. Despite progress, its etiology has not yet been elucidated. We report an additional case with an unusual clinical presentation.

Ossifying renal tumor of infancy: a case report

Ossifying renal tumor of infancy (ORTI) is an extremely rare benign renal solid tumor with typical clinical and pathological features. Most cases are diagnosed in infants that are less than 12 months of age and is more common in males. The first symptom in most patients is painless gross hematuria. Microscopically, the tumor has three main components: an osteoid core, osteoblast-like cells, and spindle cells. We reported a case of a 21-day-old patient diagnosed with ORTI who underwent partial nephrectomy and had good follow-up. The unique features of this case are the strong expression of Wilms Tumor-1 (WT-1) and a high Ki-67 index in the hot spot area. ORTI is considered to have a favorable prognosis. Due to the rarity of WT-1 positivity and high Ki-67 index, we should be highly aware that this patient needs to be followed closely. In addition, we reviewed the available literature on ORTI, with the aim of summarizing the diagnostic and therapeutic experience. The diagnosis needs to be given cautiously on the basis of clinical symptoms, imaging, and pathologic examination. Depending on the location and extent of the tumor, surgery can be performed by partial nephrectomy or nephrectomy to avoid overtreatment.

Ossifying Renal Tumor of Infancy: Laparoscopic Treatment and Literature Review

We present an unusual case of a rare ossifying renal tumor of infancy. A 6-month-old male initially presented with gross hematuria and without any palpable abdominal mass. Renal ultrasound and MRI showed a right lower pole, calcified, endophytic renal mass. Laparoscopic radical nephrectomy was performed without complications. Pathology demonstrated an ossifying renal tumor of infancy. We report this case, in addition to a review of the literature for similar cases, to highlight a rare renal tumor in infancy that can be managed laparoscopically.

Ossifying Renal Tumor of Infancy: Report of a Case With Positive WT1 Immunohistochemistry and High Mitotic Index and Review of the Literature

Ossifying renal tumor of infancy (ORTI) is a rare, benign pediatric tumor of the kidney. Since first reported by Chatten in 1980, 23 cases have been published. Previous authors have argued that ORTI might originate from nephrogenic rests, thereby sharing a pathogenic relationship with Wilms' tumor (WT). ORTI is characterized histologically by a population of polygonal osteoblast-like cells around an osteoid core and densely cellular component of blastemal-like or spindle cells. While the immunohistochemical profile of the cellular components has been reported, to the best of our knowledge, the status of WT1 expression has only been reported once, where it showed negative marking. Mitoses have been described only sporadically in this neoplasm. We report on a case of ORTI with positive WT1 immunohistochemical marking and numerous mitoses. This case highlights a possible pitfall for misdiagnosing ORTI as a WT and provides additional insight into its pathogenesis.

Ossifying renal tumor of infancy (ORIT): The clinicopathological and cytogenetic feature of two cases and literature review

Ossifying renal tumor of infancy (ORTI) is a rare benign pediatric renal tumor, which has typical clinical and pathological features. In this article, the histological features, immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) assay of two cases of ORTI were performed and the literatures were reviewed. Both of the patients presented to hospital with painless gross hematuria without other symptoms. One is 6 months old male, another is 5-month-old. After several diagnostic procedures, they underwent surgery and the histological diagnosis of ORTI was finally made. Grossly, the tumor had a nodular or irregular appearance, often partially calcified and located in the renal pelvis and calyces. The cut surface of this mass was grey-white, solid and firm. Histologically, the tumor was composed of three major histologic components: osteoblast-like cells, spindle cells, and an osteoid core. Immunohistochemistry staining revealed that osteoblast-like cells were positive for EMA, Vimentin and STAB2. Spindle cells were strongly immunoreactive for Vimentin, WT-1 and focally positive for SMA, but were negative for CK, PAX8 and PAX2. The FISH studies with CEP4 probe on interphase nuclei from the two ORTIs, revealed trisomy 4 were 8.97% (case 1) and 12.23% (case 2). Our study showed that clonal trisomy 4 may be considered as a cytogenetic feature of ORTI, which makes it distinct from other pediatric renal tumor.

An approach to renal masses in pediatrics

Renal masses in children may be discovered during routine clinical examination or incidentally during the course of diagnostic or therapeutic procedures for other causes. Renal cancers are rare in the pediatric population and include a spectrum of pathologies that may challenge the clinician in choosing the optimal treatment. Correct identification of the lesion may be difficult, and the appropriate surgical procedure is paramount for lesions suspected to be malignant. The purpose of this article is to provide a comprehensive overview regarding the spectrum of renal tumors in the pediatric population, both benign and malignant, and their surgical management.