Juxtaglomerular cell tumor in an 8-year-old girl

Juxtaglomerular cell tumor (JGCT) is an extremely rare renal neoplasm in the pediatric population. It is considered a benign tumor arising from the juxtaglomerular apparatus of the kidney. JGCT has characteristic clinicopathologic features, but its cytogenetic features are unknown. We report a case of JGCT in an 8-year-old female who presented with severe hypertension, elevated serum renin level, and a well circumscribed tumor in the right kidney. Protogranules of renin was identified in the cytoplasm of the tumor cells by electron microscopic examination. Fluorescence in situ hybridization revealed monosomy of chromosomes X, 6, 9, 11, 15, and 21.     

Undifferentiated Renal Cell Carcinoma in Infancy: Report of a Case and Review of Literature

A case of rapidly progressed undifferentiated renal cell carcinoma in a 2 2/12-month-old boy is reported. The histology is characterized by sarcomalike spindle and pleomorphic cells and bizarre giant cells, thus creating many difficulties in the differential diagnosis. The diagnosis of renal cell carcinoma was established on the basis of tubular formation by clear and granular cells observed in a few discrete areas.

The literature on renal cell carcinoma occurring under 10 years of age was reviewed, with special attention given to histological typing. It is general & believed that renal cell carcinoma in children is well differentiated, but 2 of 39 cases reviewed were undifferentiated. We conclude that renal cell carcinoma in infants or young children may have an undifferentiated, atypical histological appearance and can progress rapidly. The differential diagnosis from anaplastic Wilms' tumor and sarcomatous tumors of the kidney in children is discussed.     

Perivascular Epithelioid Cell Tumor of the Orbit: A Case Report and Review of the Literature

We present a unique case of a perivascular epithelioid cell tumor (PEComa) in the orbit of a 9-year-old female patient. The entity of PEComas has been described only recently. Characteristic histologic features and an immunohistochemical profile of negativity for epithelial markers and positivity for melanogenesis-related markers define the tumors. In children and young adults, this tumor has a predilection for the falciform ligament and ligamentum teres of the liver. It is associated with, but not exclusive to, tuberous sclerosis. To the best of our knowledge, this is the first reported case of a PEComa of the orbit in a child or adult. The main differential diagnoses for this melanin pigment-producing lesion include melanoma and pigmented paraganglioma. The histologic features, immunohistochemical profile, ultrastructural studies, and molecular studies led us to favor a diagnosis of PEComa. The prognosis of this entity is undetermined due largely to the small number of reported cases.     

Pediatric Inflammatory Myofibroblastic Tumor With Late Metastasis to the Lung: Case Report and Review of the Literature

Inflammatory myofibroblastic tumors (IMTs) are challenging lesions with respect to classification, differential diagnosis, and biologic potential. In children, extrapulmonary IMTs, particularly those from the abdomen or mesentery, are generally aggressive, with frequent local recurrences. There are few documented patients with distant metastasis, and most of these had metastases at presentation or developed metastases within months to a few years. We add to the short list of metastatic extrapulmonary IMTs a pediatric patient in whom the primary lesion was widespread in the abdomen at presentation and metastatic disease to the lung was diagnosed 9 years after the primary resection. We describe the clinical and pathologic features of this patient and review the characteristics of extrapulmonary IMTs with distant metastasis reported in the literature.     

Multicentric Bilateral Renal Cell Carcinomas and Avascular Leiomyoma in a Child

We report a unique case of multicentric bilateral renal cell carcinomas and a simultaneous large renal vascular leiomyoma in an 11 -year-old child with sickle cell anemia. The patient presented with several episodes of massive hematuria. Abdominal sonography and computed tomography demonstrated bilateral renal neoplasms and the patient was clinically thought to have bilateral Wilms' tumor. An initial biopsy of the lower pole of right kidney revealed a renal cell carcinoma. Accordingly, bilateral renal angiography followed by right total nephrectomy and left upper pole partial nephrectomy were performed. Pathologic studies showed multicentric, bilateral renal cell carcinomas (two in the right kidney and one in the left kidney), of clear, granular, and oncocytic cell types. A simultaneous large vascular leiomyoma was also present in the right kidney. The smooth muscle nature of the leiomyoma was determined by light microscopy, immunohistology, and electron microscropy. The diagnostic difficulties in distinguishing them from other renal tumors are discussed.     

Juxtaposed Cystic Nephroma and Wilms' Tumor

We report a case of juxtaposed Wilms' tumor (WT) and cystic nephroma (CN) in a 21-month-old girl which gave rise to radiological diagnostic difficulty. Preoperative chemotherapy was given, resulting in marked tumor necrosis but the cystic nephroma remained untouched. Histological examination showed characteristic features of a triphasic WT and a CN; the two lesions were separated by a thick fibrous capsule. While everybody agrees that WT and cystic partially differentiated nephroblastoma (CPDN) are closely related, there are two opposite views about their relationship to CN. One is that CN may represent the final step in maturation of WT and CPDN. Other authors argue that there is no evidence to support this theory but believe CN might have something in common with nephrogenic rests. We suggest that the two lesions in the present case may have originated from two intralobar nephrogenic rests, which would strengthen the latter view. Received November 2, 1998; accepted February 16, 1999.     

Giant Cell Tumor of Soft Tissue with Pulmonary Metastases: Pathologic and Cytogenetic Study

Giant cell tumor of soft tissue (GCTST) has gained general acceptance as an uncommon but distinct primary soft tissue tumor since it was first described in 1972. GCTST is predominantly seen in adults and typically shows uniformly dispersed osteoclast-like giant cells admixed with oval to polygonal mononuclear cells. It usually follows a benign clinical course, although the malignant variant has been described in cases in which the mononuclear cells demonstrate obvious dysplastic features. It is still not clear whether the two variants belong to the spectrum of the same tumor. No cytogenetic chromosomal abnormalities have been reported in the literature of GCTST. Interestingly, the osseous counterpart of giant cell tumor, which shares similar histologic features, quite often displays a telomeric association at the cytogenetic level, a finding that has never been reported in GCTST. We report the case of a 12-year-old girl with GCTST of the right leg that metastasized to the lung. Cytogenetic studies from the primary tumor showed the phenomenon of telomeric association involving multiple chromosomes.     

Castleman's Disease of the Left Triceps in a Child Suspected to Be a Small Round Cell Tumor of Childhood

Castleman's disease (CD) is histologically characterized by a proliferation of polyclonal small lymphocytes and plasma cells. The clinical presentation varies widely, but most commonly manifests as a solitary mediastinal mass, incidentally found on radiographic examination. We present a case of a 10-year-old girl who exhibited a left arm mass which, preoperatively and on frozen section, was diagnosed as a small round cell tumor of childhood (SRCT). This report emphasizes the unusual location of CD in the soft tissue and as a rare entity to be considered in the differential diagnosis of SRCT. Received January 15, 1999; accepted July 12, 1999.     

Clear Cell Adenocarcinoma of the Cervix in a Child without In Utero Exposure to Diethylstilbestrol: A Case Report and Review of the Literature

We describe the case of a primary cervical tumor in a 6-year-old child that was originally suspected to be an embryonal rhabdomyosarcoma botryoides. Histologic analysis revealed a clear cell adenocarcinoma. Despite a direct search and questioning for maternal exposure to diethylstilbestrol, this was not documented. Clear cell adenocarcinoma is an extremely rare neoplasm that should be kept in the differential diagnosis of cervicovaginal lesions in children, even in the absence of a clinical history of in utero diethylstilbestrol exposure. We discuss the hypothesized pathogenesis and review the literature on this unusual tumor.     

Primary Ovarian Malignant Melanoma Arising in Teratomatous Component of Mixed- Germ Cell Tumor in a Child: Case report

Primary ovarian malignant melanoma arising in teratomatous component of germ cell tumors is seen extremely rare with most reports being only of single cases and small series in reproductive aged woman and mostly from cystic teratoma, whereas information on pediatric presentation is sparse. This case is reported for being extremely rare tumor.     

Successful Treatment of a Mediastinal Endodermal Sinus Tumor in a 2-Year-Old Child

The article describes a primary mediastinal endodennal sinus tumor in a child. The employment ofmultidrug therapy combined with surgical treatment resulted in a long-term remission in this rare tumor.     

Granular Cell Tumor of the Thyroid Gland in a Girl Receiving High-Dose Estrogen Therapy

We describe the first case of a granular cell tumor of the thyroid. The tumor appeared while a girl was receiving high-dose estrogen therapy for tall stature. The tumor, however, did not contain estrogen or progesterone receptors. Although granular cell tumors occur twice as commonly in women as in men, the results of this case study do not provide evidence that tumor growth is mediated by direct estrogen or progesterone stimulation.     

Pediatric Germ Cell Tumors: Protocol Update for Pathologists

The therapy for pediatric germ cell tumors has historically been widely variable and institution dependent. The efforts to provide consistent, biology-driven therapy through Intergroup protocols has been a relatively recent phenomenon that has provided the framework for future protocol designs. The first Intergroup protocols confirmed that stage I malignant testicular germ cell tumors and immature teratomas at all sites in children could be treated with surgery alone followed by close observation. Future protocols currently in the planning stages may extend this low-risk category to stage I ovarian germ cell tumors of all histologic types. Low-stage extragonadal germ cell tumors may be placed in a new intermediate risk category. Particular pathologic issues that were raised and reported during the first protocols and that may impact on future protocol design include the presence and size of foci of endodermal sinus tumors within low-stage immature teratomas at all sites. Accurate staging will grow more critical in future protocols. The ability to recruit international cooperative groups will determine the success of chemotherapy tailored to specific subgroups that now must be lumped for statistical purposes. Lastly, companion biologic studies will be critical to defining the different subtypes of germ cell tumors and to determining predictors of biologic behavior.     

Renal Metanephric Adenoma With Previously Unreported Cytogenetic Abnormalities: Case Report and Review of the Literature

We report a case of a renal metanephric adenoma in a 10-year-old boy, in which cytogenetic analysis showed a balanced translocation, t(9;15)(p24;q24) and a balanced paracentric inversion of chromosome 12, inv(12)(q13q15). Immunohistochemically, the tumor showed diffuse reactivity for cytokeratin AE1/AE3, CAM5.2, CD57, and WT1; patchy reactivity for CD56; and focal reactivity for cytokeratin 7, epithelial membrane antigen, and CD10. Tumor cells were entirely nonreactive for α-methyl acyl coenzyme A racemase. Published cytogenetic data for metanephric adenomas are limited, and this is the first report of these cytogenetic abnormalities. The involvement of the chromosome region 9p24 is particularly interesting because of the recent identification of a tumor suppressor gene, KANK (kidney ankyrin repeat-containing protein), at this locus.     

Giant Cell Tumor in the Skull of a 9-year-old Child: Immunohistochemistry to Confirm a Diagnosis Rare for Age and Site

Giant cell tumor of the bone is usually located within the epiphysis of a long bone, the majority of the lesions occurring in the third and fourth decades of life. We report an unusual case of giant cell tumor (GCT) arising in the parietal skull bone of a 9-year-old girl. The tumor exhibited histologic findings typical for GCT, with conspicuous intravascular giant cells. Based on microscopic features, not only conditions like aneurysmal bone cyst or bone changes associated with hyperparathyroidism but also tumors such as chondroblastoma or osteosarcoma had to be considered. Immunohistochemistry revealed strong reactivity of the tumor giant cells and normal bone osteoclasts with CD68 but not Mac-387; tumor stromal cells were uniformly negative for both. The stromal cells exhibited two immunohistochemically distinct phenotypes. One, involving 50-80% of the tumor cells, exhibited negative lysozyme staining with positivity of proliferating cell nuclear antigen (PCNA) in about 30% of the nuclei. The other showed reactivity with lysozyme but negative PCNA staining. Immunohistochemistry thus helped to distinguish chondroblastoma and osteosarcoma, in which lysozyme positivity would reside in macrophages but not within stromal cells. Instead, chondroblastoma would exhibit protein S-100 positivity in the tumor cells. The biological behavior of GCT is difficult to predict based on morphology alone, although the malignant potential seems to rest in the stromal cells rather than the giant cells. Specifically, in reported cases, the intravascular occurrence of giant cells in GCT is not associated with an increased incidence of metastasis.     

Tumor biology,biomarkers, and liquid biopsy in pediatric renal tumors

The expansion of knowledge regarding driver mutations for Wilms tumor (WT) and malignant rhabdoid tumor of the kidney (MRT) and various translocations for other pediatric renal tumors opens up new possibilities for diagnosis and treatment. In addition, there are growing data surrounding prognostic factors that can be used to stratify WT treatment to improve outcomes. Here, we review the molecular landscape of WT and other pediatric renal tumors as well as WT prognostic factors. We also review incorporation of circulating tumor DNA/liquid biopsies to leverage this molecular landscape, with potential use in the future for distinguishing renal tumors at the time of diagnosis and elucidating intratumor heterogeneity, which is not well evaluated with standard biopsies. Incorporation of liquid biopsies will require longitudinal collection of multiple biospecimens. Further preclinical research, identification and validation of biomarkers, molecular studies, and data sharing among investigators are crucial to inform therapeutic strategies that improve patient outcomes.     

Endodermal Sinus Tumor of the Parotid Gland in a Child

We report a case of a 16-month-old girl with a primary endodermal sinus tumor (EST) of the parotid gland. The girl was admitted to the hospital with a left side cervical tumor with a quick growth (within 3 wk). The tumor was surgically resected. The gross examination showed a 7.0-cm hemorrhagic and fragmentized mass. Diagnosis of an EST was established on the hematoxylin and eosin-stained slides from the resected material. Elevated serum alpha-fetoprotein (AFP) levels were detected and follow-up examinations of the patient did not show ESTs in other locations or other manifestations due to the tumor. The patient received chemotherapy after the surgery and remained alive without evidence of disease at the time of this writing (2 years after the diagnosis). As far as we know, this is the second report in the literature of a parotid glands EST.     

Embryoma (or Embryonal Tumor) of the Parotid Gland: Report of two Cases

Embryoma is the name applied by Vawter and Tefft to congenital tumors of the parotid gland. These tumors are highly uncommon, and they must not be confused with malignant tumors—i.e., cylindroma, embryonal carcinoma, or teratoma. Alone, complete surgical exeresis is necessary without radiation or chemotherapy. Two observations of embryoma are reported because of the diagnostic and therapeutic problems involved.     

Renovascular Hypertension in a Child with Rett's Syndrome

ABSTRACT. A girl with Rett's syndrome and renovascular hypertension because of a stenosis in the right renal artery is described. The girl was operated on twice because of the stenosis. Her blood pressure normalized after the second operation in which the artery was reconstructed. High blood pressure causes neurological symptoms which may be difficult to distinguish from the basic disease. The importance of the measurement of blood pressure in every child with neurological symptoms is emphazised. The possibility of an association between renovascular hypertension and Rett's syndrome should be studied in large series.