[Pediatric pancreatic lesions: a clinicopathological analysis of 42 cases].

Objective: To investigate the clinicopathological characteristics of pancreatic lesions in children. Methods: The clinicopathological data of pancreatic lesions in children were analyzed including 42 cases of pancreatic tumors diagnosed from January 2000 to May 2021 in Guangzhou Women's and Children's Medical Center, Guangzhou, China. Histological and immunohistochemical assessments were performed. Related literature was reviewed. Results: The 42 pediatric patients with pancreatic lesions aged 1 day to 12 years (mean, 4.25 years). There were 23 males and 19 females. Clinical presentations included abdominal masses, abdominal pain, vomiting and persistent hypoglycemia after birth. Ultrasound and computerized tomography examination showed space-occupying pancreatic lesions in 31 cases, but no detectable pancreatic lesions in 11 cases. Histologically, among the 42 cases, 22 cases (52.4%) were neoplastic, including 18 cases of epithelial origin. Nine cases of pancreatoblastoma showed that the epithelial tumor cells were arranged in a trabecular pattern, with squamous nests. Six cases of solid-pseudopapillary tumors revealed hemorrhagic and necrotic cysts and monomorphic epithelioid cells arranged in solid sheets, nests or pseudopapillae. Two cases of neuroendocrine tumors showed tumor cells arranged in cords or nests; one case had a mitotic count of about 3/10 high power field, and a Ki-67 index of about 5%, which was consistent with G2 neuroendocrine tumor; the other case showed tumor cells with cytological atypia, brisk mitoses, about 25/10 HPF and a Ki-67 index of about 80%, consistent with small-cell type neuroendocrine carcinoma. The case of acinar cell carcinoma showed high cellularity, tumor cells in solid, cord-like or acinar-like arrangement with little stroma, and monotonous tumor cells with single distinct nucleolus. There were 4 cases of mesenchymal tumors, including 3 cases of Kaposi's hemangioendothelioma and 1 case of inflammatory myofibroblastic tumor. Among the 20 cases (47.6%) of non-neoplastic lesions, there were 11 cases of hyperinsulinism with ATP-sensitive potassium channel abnormality (HAPCA). Severn cases of diffuse type HAPCA in which the islets scattered between the pancreatic acinar tissue, enlarged, and prominent nuclei. Three cases of focal type HAPCA showed pancreatic islet hyperplasia in the form of nested nodules (0.6-1.5 cm). One case of atypical type HAPCA had extensive islet hyperplasia in pancreatic tissue, and scattered proliferation of nest-like nodules was noted. There were also 7 cases of pseudocyst and 2 cases of congenital cyst. Immunohistochemically, pancreatoblastomas were diffusely positive for CKpan, CK8/18, and ß-catenin (nuclear staining of squamous nests only). Solid-pseudopapillary tumors expressed CD10, cyclin D1, CD99, vimentin, CD56, and ß-catenin (nuclear staining). Neuroendocrine tumors were positive for CK, Syn, NSE, CgA, CD56, and ß-catenin (membranous staining). The acinar cell carcinoma was positive for CK8/18, trypsin, and ß-catenin (membranous staining). Conclusions: Pancreatic lesions in children have a wide range of histopathological types. HAPCA is the most common lesion of newborns. Pediatric pancreatic tumors are rare and mostly malignant. It is important to recognize them and make correct pathological diagnoses.

[Pediatric vascular tumors of liver:a clinicopathological study of 22 cases].

Objective: To investigate the clinicopathological features of hepatic vascular tumors in children. Methods The clinical characteristics, histology and immunohistochemical staining results were summarized and analyzed in 22 cases of hepatic vascular tumors in children at Guangzhou Women and Children's Medical Center from September 2007 to November 2020. Results: The 22 patients aged from 1.0 month to 2.5 years (mean age 9 months). There were 10 males and 12 females. Five cases were found in premature and had low birth weight infants; three cases were discovered in the antenatal period; one patient also had cutanous hemangioma; six patients had associated anemia; Kasabach-Merritt phenomenon was not seen in any patient. CT examination showed 17 tumors were solitary and five were multifocal lesions. Macroscopically, the tumors size ranged from was 0.6 cm to 11.0 cm; the cut surface was solid, gray red and brown in color, and in six cases there were hemorrhage and necrosis in the central area. Microscopically,15 cases of solitary congenital hepatic hemangiomas showed characteristic necrosis in the central area, with loose fibrous tissues at periphery. Proliferation of capillaries, residual bile ducts between the vascular lumens, and dilated thrombosed vascular channels were seen, and contained extramedullary hematopoietic foci and calcification. Five cases of multiple hepatic infantile hemangiomas showed capillaries of different sizes composing of plump endothelium and pericytes and were arranged in lobular or diffuse patterns. Two cases of cavernous hemangioma (venous malformation) consisted of dilated thin-walled blood vessels with branch-like pattern lined with flat endothelial cells. Immunohistochemically, all 22 case expressed vascular endothelial markers CD31 and CD34, but D2-40 was negative. Glut1 was positive in five cases of multiple hepatic infantile hemangiomas, and the other cases were negative. Conclusion: Hepatic vascular tumors in children are rare, and their classification is different from that of adults. It is of great significance to make clear pathologic diagnosis.

[Gonadal neoplastic related lesions in children with disorders of sexual development: a clinicopathological study of twelve cases].

Objective: To investigate the clinicopathological features of gonadal neoplastic related lesions in children with disorders of sexual development (DsD). Methods: The clinical manifestations, chromosomal karyotype, histology and immunophenotype of 12 cases of neoplastic related lesions from Guangzhou Women and Children's Medical Center, Guangzhou were analyzed during Jan 2015 to May 2020. Results: Twelve cases of neoplastic related lesions were screened in 205 cases of DsD, and 6 patients with gonadal germ cell neoplasia aged 3-13 years with an average age of 8.3 years. There were 2 males and 4 females. Clinical features showed malformation of external genitalia in 2 cases, short stature in 2 cases, clitoral enlargement in 1 case, lower abdominal pain and a huge pelvic mass in 1 case. Chromosomal karyotyping of peripheral blood showed 2 cases of 46XY and 4 cases of 45X/46XY. Fourteen gonadal specimens were examined. Microscopically, 1 case showed dysgerminoma in left ovary, and malignant mixed germ cell tumors in right ovary, as well as gonadoblastoma (GB) and undifferentiated gonadal tissue (UGT). The remaining 5 cases were all precursor lesions of germ cell tumor. Six specimens showed GB, 3 of UGT, and 3 specimens showed germ cell neoplasia in situ (GCNIS), one of which was accompanied by intratubular seminoma and 1 was GB with GCNIS. The other 6 patients with DsD were aged from 8 months to 2 years and 5 months, including 5 males and 1 females. Clinical manifestations showed 5 cases of hypospadias and 1 case of bilateral indirect inguinal hernia. Microscopically, 6 cases showed maturation delay of gonocytes in seminiferous tubules. Immunohistochemically, the primordial germ cells/gonocytes expressed OCT3/4, PLAP and c-KIT in the 12 cases. Conclusion: Gonadal neoplasia in children with DsD is mainly precursor lesions of germ cell tumor and improved understanding of these lesions is of great significance.

[Pathologic features on gonadal changes of sexual developmental disorders in children].

Objective: To investigate the pathologic features of gonadal tissues of disorders of sexual development (DSD) in children. Methods: Fifty-three cases of gonadal developmental disorders were collected from July 2015 to August 2017 at Guangzhou Women and Children's Medical Center. Clinical manifestations, karyotypes, sex hormone levels, ultrasound imaging, histology and immunophenotype of gonadal tissues were analyzed. Results: The age of patients ranged from 7 months to 17 years with an average of (50.7 ± 47.1) months. Social genders of the patients included 32 males and 21 females. Forty-eight patients had abnormal sex hormone levels. Clinical presentations included: toward female genitalia in 25 cases, male genitalia tendency in 17 cases and ambiguous external genitalia in 11 cases. Hypospadias was seen in 31 cases and short stature was seen in 8 cases. Chromosomal karyotyping of peripheral blood revealed 23 cases of sex chromosome disorders, 22 cases of 46 XY disorders, of which 3 cases were 5α-reductase deficiency and 8 cases of 46 XX disorders. Ultrasound examination showed cryptorchidism in 30 cases, including 16 cases of unilateral, 14 cases of bilateral and 1 case presenting a huge pelvic tumor. A total of 97 gonadal tissues from 53 cases of DSD were examined, including 9 cases of unilateral and 44 cases of bilateral gonads. Microscopically, 55 gonads (56.7%) showed dysplastic testes including 17 unilateral and 19 bilateral gonads. Fourteen were streak gonads (14.4%) including 8 unilateral and 3 bilateral gonadal tissues. Nine streak gonad with epithelial cord-like structures (9.3%) were found, of which 5 were unilateral and 2 were bilateral lesions. Seven gonads were ovotestis (7.2%), unilateral in 5 cases (the other side of the gonads of ovary in 4 cases, 1 case of dysplastic testes) and bilateral in 1 case. Seven gonads showed follicular-rich ovarian tissue (7.2%). One case showed bilateral dysplastic testes with gonadoblastoma and ectopic adrenal cortex. One case of streak gonad showed epithelial cord-like structures and undifferentiated glandular tissue embedded in malignant mixed germ cell tumors (mixed gonadoblastoma, dysgerminoma, mature teratoma and yolk sac tumor). One case had testicular microlithiasis. Uterus and fallopian tube structures were found in 11 cases. Immunohistochemical stains were performed in 15 cases. D2-40, PLAP and CKIT were expressed in germ cells and Calretinin, WT1 and inhibin were positive in Setoli cells. SALL4 and OCT3/4 were positive in 3 cases. Inhibin highlighted interstitial Leydig cells in 2 cases. GPC3 was positive in yolk sac tumor component. Conclusions: Gonadal dysgenesis presents a broad spectrum of gonadal phenotypes with variable degrees of differentiation. The development of bilateral gonadal tissues has certain variability. Chromosomal karyotypes have no correlation with gonadal phenotypes. Accurate histopathologic diagnosis of gonadal dysgenesis plays an important role in the treatment and prognosis of the patient.

[Clinicopathologic study of pediatric vascular anomalies: a report of 117 cases].

OBJECTIVE: To study the clinicopathologic features of pediatric vascular anomalies and application of ISSVA classification. METHODS: The clinical features, histopathologic findings and immunohistochemical results were analyzed in 117 cases of pediatric vascular anomalies encountered during the period from May 2014 to May 2015. RESULTS: A total of 117 cases of vascular anomalies were studied. The age of patients ranged from 18 hours after birth to 11 years (mean age =34 months and median age =27 months). There were 73 male patients and 44 female patients, with the male-to-female ratio being 1.7∶1.0. Congenital skin lesions were found in 37 cases (31.6%). The common sites of involvement included head and neck region (46 cases, 39.3%), trunk (28 cases, 23.9%), extremities (14 cases, 12.0%) and internal viscera (31 cases, 26.5%). According to the new ISSVA classification, there were 74 cases of vascular malformations and 43 cases of vascular neoplasms (ratio=1.7∶1.0). The commonest vascular tumor encountered was infantile hemangioma (21 cases, 48.8%), including 17 cases in proliferative phase and 4 cases in involutive phase. Thirteen cases (23.3%) of congenital hemangioma were found, with 8 cases of rapidly involuting congenital hemangioma and 5 cases of non-involutive congenital hemangioma. Three of the congenital hemangioma occurred in liver. There were 5 cases (11.6%) of pyogenic granuloma, 3 cases (7.0%) of tufted angioma and 1 case (2.3%) of Kaposiform hemangioendothelioma. Amongst the 74 cases of vascular malformations encountered, lymphatic malformation was found in 47 cases (63.5%), venous malformation in 15 cases (20.2%), lymphatic-venous malformation in 11 cases (14.9%) and arteriovenous malformation in 1 case (1.4%). All cases of vascular anomalies were all positive for CD31 on immunostaining. Glut1 and CD15 were positive both in proliferative and involutive phases of the 21 cases of infantile hemangioma, while other vascular tumors and vascular malformations were negative. Forty-seven cases of lymphatic malformation and 11 cases of lymphatic-venous malformation showed D2-40 expression. Focal positivity for D2-40 was demonstrated in 3 cases of tufted angioma and 1 case of Kaposiform hemangioendothelioma. CONCLUSIONS: Vascular anomalies affecting infants and children include tumors and malformations. Accurate histopathologic diagnosis and ISSVA classification of the various types of vascular anomalies play an important role in clinical management.

Laser photobiostimulation-induced hypoalgesia in rats is not naloxone reversible.

Laser photobiostimulation (LPBS) at the pulsing frequency of 4 Hz applied to the low resistance point located at the base of the tail of the rat, (Governing Vessel Meridian 1), produced a hypoalgesic effect, measured by tail-flick and hot-plate techniques. Pre-treatment with low dose naloxone (2 mg/kg) did not reverse the hypoalgesic effect of LPBS. High dose naloxone (20 mg/kg) reversed only partially, but significantly, the hypoalgesic effect of LPBS measured by hot-plate, but not that measured by the tail-flick technique. These data suggest that mechanisms other than endogenous opioids may be involved in LPBS-induced hypoalgesia.