Ayper Kaçar

Primary hydatid cyst of the rib mimicking chest wall tumor: a case report.

Hydatidosis, caused by Echinococcus granulosus, is still an endemic parasitic disease in the Mediterranean area, South America, North Africa, and Australia. The most common anatomic location of hydatid disease is the liver, followed by the lung. Hydatidosis is located in the bones in 0.5% to 2% of all cases. A hydatid cyst can be seen in any part of the body. However, primary hydatid cyst of the rib in childhood is exceedingly rare. We report the first case of a pediatric hydatid cyst of the rib mimicking chest wall tumor.

Sertoliform cystadenoma: a case with overlapping features.

The 1st pediatric case of sertoliform cystadenoma with unique features is described herein. The patient is a 6-year-old boy who presented with gynecomastia and a left testicular cystic mass. Histopathologically the tumor was found to originate from the rete channels, filling and distending them with areas of mural Sertoli cell proliferations reminiscent of large cell Sertoli cell tumor (noncalcifying form) and showing widespread intratubular Sertoli cell proliferation islands in the vicinity. Histopathologic and immunohistochemical features are described in light of the relevant literature.

Metanephric stromal tumor: a challenging diagnostic entity in children

A case with a renal mass diagnosed as metanephric stromal tumor is presented. A 6-year-old boy presented with frequently recurring urinary tract infections. He had been followed up at different medical centers for the last 2 years with a 2 × 2 cm simple cyst localized in the inferior pole of the left kidney. At our center, ultrasonography revealed a heterogeneous mass in the left kidney with a central cystic component. The patient underwent operation for left renal mass, and heminephrectomy was performed. The 5 × 4 × 2.5 cm left heminephrectomy specimen showed a partially cystic mass composed of bland spindle cells distributed haphazardly, entrapping tubules and glomeruli and producing fine collarettes around some tubules. The cysts were lined with a 1-layered flat or cuboidal epithelium. Histopathologically, the tumor was diagnosed as metanephric stromal tumor. Metanephric stromal tumor is a rare renal neoplasm of childhood that can present as a cystic mass, and the solid component can go radiologically undetected because of the blurring infiltrative margins. By presenting this rare entity, the authors suggest that this should be included in the differential diagnosis, thereby helping to avoid complications and unnecessary treatment.

Spinal Tuberculosis (Pott's disease) Mimicking Paravertebral Malignant Tumor in a Child Presenting with Spinal Cord Compression

Paravertebral tumors may interfere with the radiological and clinical features of spinal tuberculosis. We report a case of a 3-year-old boy with spinal tuberculosis who was initially misdiagnosed as having a paraspinal tumor. The diagnosis of tuberculosis was made on the basis of intraoperative findings and confirmed by histopathology. This case highlights the importance of awareness of the different radiographic features of spinal tuberculosis, which can mimic a spinal malignancy. In order to avoid delayed diagnosis, pediatricians and radiologists must be aware of spinal tuberculosis, which may interfere with other clinical conditions.

Anaplastic lymphoma kinase gene expression in small round cell tumors of childhood--a comparative ımmunohistochemical study.

The focus of this study was to investigate anaplastic lymphoma kinase (ALK) expression by immunohistochemistry using a highly specific antibody. Distribution and frequency of ALK expression may provide a clue for ALK inhibitor use in small round cell tumors of childhood. The study group involved 76 small round cell tumors of childhood, which composed of 11 rhabdomyosarcomas, 13 Wilms tumors, 7 Ewing sarcoma/primitive neuroectodermal tumors, 34 peripheral neuroblastic tumors, and 11 acute lymphoblastic lymphoma. Anaplastic lymphoma kinase protein expression in small round cell tumors of childhood is poorly described in the literature. The findings of our study highlight a potential and possible role of targeting ALK in pediatric solid tumors by using ALK immunohistochemistry. Anaplastic lymphoma kinase may also have an oncogenic role in rhabdomyosarcomas and peripheral neuroblastic tumors, and they may possibly be treated with ALK inhibitors. Anaplastic lymphoma kinase expression in Wilms tumors is not reported in the literature, previously. Our study evaluated ALK expression in Wilms tumor samples.

Paraganglioma presenting with marked proteinuria: a case report.

Paragangliomas are rare neuroendocrine tumors that arise from sympathetic and parasympathetic paraganglia. In children, most of them are functional tumors. Presenting symptoms such as sustained or paroxysmal elevations in blood pressure, headache, sweating, and palpitations are related to catecholamine hypersecretion. A previously healthy 8-year-old boy presented with marked proteinuria, hypertension, and heart murmur. Imaging revealed an 81×43×45 mm sized solid mass extending from right retroaortic area to left suprarenal region. Measurements of catecholamines suggested the diagnosis of paraganglioma. Pathologic examination confirmed the diagnosis. Complete tumor resection was performed. Proteinuria, hypertension, and cardiac signs resolved after surgery. Proteinuria has been described as a rare manifestation of paragangliomas in adult patients. This is the first case of a paraganglioma presenting with massive proteinuria in a child.

Spindle Cell Rhabdomyosarcoma Displaying CD34 Positivity: A Potential Diagnostic Pitfall; Report of Two Pediatric Cases CD34 Pozitivitesi Gösteren İğsi Hücreli Rabdomyosarkoma: İki Pediatrik Tuzak Olgunun Sunumu

Abstract Spindle cell rhabdomyosarcoma is a rare subtype of rhabdomyosarcoma mainly seen in children. Occasional aberrant staining with a variety of immunohistochemical markers has been noted. The aberrantly expressed markers include alpha-smooth muscle actin, cytokeratin, S100, neurofilaments, CD20, immunoglobins, and CD117. We report herein two pediatric cases displaying strong CD34 positivity and one with additional focal CD117 positivity, causing considerable difficulty in distinction from solitary fibrous tumor and extra-gastrointestinal stromal tumor. To our knowledge, CD34 staining has been merely reported in rhabdomyosarcoma. Spindle cell rhabdomyosarcoma has to be considered in the differential diagnosis of childhood spindle cell tumors. Post-chemotherapy specimens should be evaluated in caution, since chemotherapy can cause considerable changes in tumor antigen expression. Since CD117 and CD34 are stem cell markers, their positivity in pediatric tumors should be interpreted with caution. Even if the morphology is not supportive, a wide immunohistochemical panel should be applied in childhood malignant solid tumors Öz İğsi hücreli rabdomyosarkoma temel olarak çocuklarda gözlenen bir rabdomyosarkom alt tipidir. Bu tümörlerde çeşitli immünohistokimyasal belirteçlerin aberran boyanma gösterebildiği bilinmektedir. Başlıca aberran boyanan belirteçler alfa düz kas aktini, sitokeratin, S100, nörofilaman, CD20, immünglobinler ve CD117’ dir. Biz bu makalede biri CD117 pozitivitesi de gösteren, kuvvetli CD34 ekspresyonuna sahip, soliter fibröz tümör ve ekstra gastrointestinal stromal tümör ile ayırıcı tanı güçlüğü yaratan 2 pediatrik tuzak olguyu sunuyoruz. Bildiğimiz kadarıyla rabdomyosarkomda CD34 pozitivitesi nadiren raporlanmıştır. İğsi hücreli rabdomyosarkoma çocukluk çağı iğsi hücreli tümörlerinin ayırıcı tanısında dikkate alınmalıdır. Kemoterapi sonrasına ait materyallerde tümör antijen ekspresyonuna ait değişiklikler olabileceğinden, dikkatli değerlendirilmelidir. CD117 ve CD34 kök hücre belirteçleri olduğundan pediatrik tümörlerde dikkatli değerlendirilmelidir. Çocukluk çağı solid tümörlerinde morfoloji düşündürmese bile immünohistokimyasal panel geniş tutulmalıdır

Recurrence of childhood nephrogenic adenoma in urinary bladder developed four years after previous surgery despite intravesical sodium hyaluronate therapy.

Nephrogenic adenoma (NA) is a rarely seen benign metaplastic lesion of the urinary tract. Its etiology is uncertain, but induced by chronic inflammation, irritation, and trauma. NA is located in the urinary tract, most commonly in the bladder. NA usually presents with hematuria and lower urinary tract symptoms. In the literature it is mostly seen in adults but about 30 cases of NAs have been reported in children. Treatment of intravesical lesions consists of transurethral resection (TUR) and fulguration and rarely partial or total cystectomy may be required in ineffective TUR. Recurrence rate is high during long-term follow-up. The intravesical application of sodium hyaluronate produces a protective effect on the glycosaminoglycan layer and delays or prevents its recurrence. We report a case of recurrent NA of the bladder in a pediatric male patient who was presented four years after previous surgery despite intravesical sodium hyaluronate therapy.

Expression of Epstein-Barr virus in children with sacrococcygeal pilonidal sinus determined by immunohistochemical methods.

In this study, we probed whether chronic infections of skin such as pilonidal sinus could be a potential site of Epstein–Barr virus (EBV) replication. Pilonidal sinus is associated with a high recurrence rate. Therefore, we decided to determine the role of EBVs presence to explain whether it is correlated with the recurrence of pilonidal sinuses. This study was conducted on 36 patient samples with sacrococcygeal pilonidal sinus. Samples were immunohistochemically stained for EBV, CD3 and CD20 expression. Thirty‐six adolescents with pilonidal disease were evaluated. EBV‐positive cells were located in dermis with high inflammatory activity. EBV‐positive cells stained positive for the B‐cell antigen CD20 and were detected in 10 of 36 (27%) pilonidal sinus specimens. Among those who had experienced a relapse, three were positive for EBV expression. In addition, EBV expression was detected in eight cases with severe inflammation, and in two with minimal or moderate inflammation. Our study advances the field by demonstrating that similar to gastrointestinal mucosa, skin could be a reservoir for EBV. EBV was found to be restricted to B cells in skin lesions, and it was found that skin lesions with severe inflammation showed higher frequency of EBV expression in comparison to minimal or moderately inflammed skin lesions. Additionally, recurrence was more frequently observed among EBV‐positive cases. These findings point out for a role of EBV infection in the recurrence of pilonidal sinuses.

A newborn with respiratory distress and hydrocephalus caused by a giant mature teratoma

Teratomas, derived from pluripotent cells, are the most common neonatal tumors and are mainly located in the sacrococcygeal region or mediastinum [3]. They commonly present as large and deforming monstrous tumors with an incidence of 1 in 20,000 to 40,000 newborns. The lesion is usually life threatening due to airway obstruction, and their aetiology is uncertain. The head and neck localization comprises 2% to 9% of all teratomas. Most are very large and complex lesions containing solid and cystic areas. These lesions contain all three germ layers and may be composed of mature or immature elements. In the neonate, the presence of immature elements does not correlate with malignant potential, and most of these teratomas are benign [1, 3, 6, 12, 13]. We present a newborn with a giant head and neck mass visualised postnatally by cranial magnetic resonance imaging (MRI). The histopathological diagnosis made on the basis of excisional biopsy was mature teratoma. Total surgical resection was not possible due to massive invasion of airways and central nervous system (CNS) by the tumor. The clinical and radiological characteristics, as well as mortality, in this case of a teratoma are discussed.