Whole-Genome and Segmental Homozygosity Confirm Errors in Meiosis as Etiology of Struma Ovarii.

Strumae ovarii are neoplasms composed of normal-appearing thyroid tissue that occur within the ovary and rarely spread to extraovarian sites. A unique case of struma ovarii with widespread dissemination detected 48 years after removal of a pelvic dermoid provided the opportunity to reexamine the molecular nature of this form of neoplasm. One tumor, from the heart, consisting of benign thyroid tissue was found to have whole-genome homozygosity. Another tumor from the right mandible composed of malignant-appearing thyroid tissue showed whole-genome homozygosity and a deletion of 7p, presumably the second hit that transformed it into a cancerous tumor. Specimens from 2 other cases of extraovarian struma confined to the abdomen and 8 of 9 cases of intraovarian struma showed genome-wide segmental homozygosity. These findings confirm errors in meiosis as the origin of struma ovarii. The histological and molecular findings further demonstrate that even when outside the ovary, strumae ovarii can behave nonaggressively until they receive a second hit, thereafter behaving like cancer.

Classic and "Dissecting" Gonadoblastoma in a Phenotypic Girl With a 46, XX Peripheral Karyotype and No Evidence of a Disorder of Sex Development.

Herein, we report a case of a 9-yr-old girl who had a 46, XX peripheral karyotype and apparent developmentally normal ovaries. She presented with abdominal pain and a right adnexal mass. No clinical or pathologic evidence of gonadal dysgenesis or undifferentiated gonadal tissue was detected. She underwent right salpingo-oophorectomy with rupture of the tumor at the time of operation due to recent adnexal torsion. The original pathologic diagnosis was gonadoblastoma and mixed germ cell tumor. Most significantly in our study, we identified a rare and novel pathway for the development of malignant mixed germ cell tumor from gonadoblastoma in the absence of identifiable dysgerminoma. The histologically identifiable steps of progression in our case were as follows: (1) residual islands of classic gonadoblastoma, (2) overgrowth by "dissecting" gonadoblastoma composed of transformed germ cells with clear cytoplasm and sex cord elements surrounded by a basement membrane, (3) stromal infiltration by dedifferentiated germ cells with loss of basement membrane, (4) formation of malignant mixed germ cell tumor. The dedifferentiated areas were composed of anaplastic germ cells with amphophilic cytoplasm that gradually replaced the sex cord elements by clonal expansion. Both the original transformed and the anaplastic germ cell components strongly expressed OCT4. We believe that the mixed germ cell tumor arose from the dedifferentiated germ cell component through neoplastic progression. This premise suggests that the germ cell component of "dissecting" gonadoblastoma rarely undergoes anaplastic change in the absence of transition to germinoma and can be the direct precursor of mixed germ cell tumor.

Classical gonadoblastoma: its relationship to the 'dissecting' variant and undifferentiated gonadal tissue.

Classical gonadoblastoma occurs almost entirely in the dysgenetic gonads of an individual who has a disorder of sex development. Approximately 40% of such neoplasms are bilateral. Almost all gonadoblastomas occur in patients who have a Y chromosome or part thereof; testis-specific protein Y-encoded 1 (TSPY1) is the putative gene. If a gonad in a patient who has a disorder of sex development contains germ cells with delayed maturation, and also harbours the TSPY1 gene, the cells can undergo transformation to classical gonadoblastoma. The latter consists of rounded islands composed of germ cells, sex cord elements and hyaline basement membrane material surrounded by a variably cellular gonadal stroma that sometimes contains steroid cells. Classical gonadoblastoma can be interpreted as a non-invasive neoplasm that is the precursor of germinoma and, indirectly, other more aggressive germ cell neoplasms. Undifferentiated gonadal tissue is the precursor of classical gonadoblastoma and contains germ cells with delayed maturation that express octamer-binding transcription factor 4 (OCT4); however, other germ cells show normal maturation and express TSPY1. If all germ cells in a patient with undifferentiated gonadal tissue involute, the result is a secondary streak. Undifferentiated gonadal tissue is a non-neoplastic condition that should be distinguished clearly from 'dissecting gonadoblastoma', a neoplasm derived from classical gonadoblastoma that is the precursor of some germinomas. 'Dissecting gonadoblastoma' is a variant of classical gonadoblastoma that has unusual growth patterns and contains both sex cord and germ cell elements. Clonal expansion of germ cells is a characteristic of the late stage of 'dissecting gonadoblastoma'.

Evidence of a dual histogenetic pathway of sacrococcygeal teratomas.

AIMS: Sacrococcygeal teratomas are rare tumours that occur most frequently in neonates, although adult cases also occur. The molecular pathogenesis of these tumours and their long-term prognosis is uncertain. We investigated the i(12p) status of a large number of primary sacrococcygeal teratomas in both children and adults, including cases with malignant germ cell tumour elements. METHODS AND RESULTS: Fifty-four sacrococcygeal teratoma specimens from 52 patients were identified, and available follow-up information was obtained. Fluorescence in-situ hybridization analysis was performed to identify isochromosome 12p [i(12p)] abnormalities on paraffin blocks of the tumours. Among the 48 paediatric patients, there were 44 teratomas and four tumours with combined teratoma and yolk sac tumour (one of whom also had primitive neuroectodermal tumour). The teratomas included 37 mature teratomas and 11 immature teratomas (four grade 1, two grade 2, and five grade 3). The 44 teratomas lacking a yolk sac tumour component were all negative for i(12p). The four tumours with a yolk sac tumour component were all positive for i(12p). The four adult cases all lacked non-teratomatous germ cell tumour components, immature elements, and i(12p). Follow-up information was available for 32 patients. Two patients with teratoma had recurrence, but were alive with no evidence of disease after long-term follow-up. One patient with combined teratoma and yolk sac tumour had recurrence 7 months after resection. The other patients were alive with no evidence of disease at last follow-up. CONCLUSIONS: Our data suggest that paediatric sacrococcygeal teratomas should be considered as two distinct groups with divergent histogenetic pathways. The prognosis of these tumours is excellent, despite rare recurrence.

Loss of SMARCA4 (BRG1) protein expression as determined by immunohistochemistry in small-cell carcinoma of the ovary, hypercalcaemic type distinguishes these tumours from their mimics.

AIMS: Molecular investigation of small-cell carcinoma of the ovary, hypercalcaemic type (SCCOHT) has revealed that it is a monogenetic tumour characterized by alteration of SMARCA4 (BRG1), encoding a member of the switch/sucrose non-fermentable (SWI/SNF) chromatin remodelling complex. A large majority of cases show loss of expression of the corresponding SMARCA4/BRG1 protein. Furthermore, three cases of SCCOHT with retained SMARCA4 protein expression showed loss of SMARCB1/INI1 expression. The aim of this study was to assess the sensitivity and specificity of loss of SMARCA4 expression as a diagnostic test for SCCOHT. METHODS AND RESULTS: We performed SMARCA4 and SMARCB1 staining in 245 tumours, many of which were potentially in the differential diagnosis of SCCOHT. We also stained 56 cases of SCCOHT for SMARCA4 and 37 of these for SMARCB1. Fifty-four of the SCCOHT cases showed complete absence of SMARCA4 expression. The two cases with retained expression showed molecular alteration of SMARCA4. Of the 217 other neoplasms with interpretable staining, all retained SMARCA4 expression. Although the majority showed diffuse, strong nuclear expression, a heterogeneous, typically weak staining pattern was present in 13% of cases. All 37 cases of SCCOHT tested and all other neoplasms, apart from three malignant rhabdoid tumours, showed retained nuclear SMARCB1 expression. Loss of SMARCA4 expression had a sensitivity of 96.55% and specificity of 100%. CONCLUSIONS: Loss of SMARCA4 expression is sensitive and specific for SCCOHT. Although some mimics show heterogeneous expression, there is retention of nuclear staining in at least a part of the tumour; therefore, only complete loss of staining should be regarded as being supportive of SCCOHT.

Cervical Carcinomas With Neuroendocrine Differentiation: A Report of 28 Cases With Immunohistochemical Analysis and Molecular Genetic Evidence of Common Clonal Origin With Coexisting Squamous and Adenocarcinomas.

Cervical neuroendocrine carcinomas are rare, aggressive tumors and their immunohistochemical features and clonal relationship to coexisting tumors are incompletely described. Twenty-eight cases were identified (17 small cell, 9 large cell, and 2 mixed), 10 of which had an invasive squamous or adenocarcinoma component. Staining for synaptophysin, chromogranin A, TTF1, c-kit, CD44, and p16 was performed. Analyses for loss of heterozygosity (LOH) at 5 polymorphic microsatellite markers (D3S1300, D9S171, D11S914, D13S319, and TP53) and X-chromosome inactivation were performed. Of 17 cases with available blocks, 13 (76%) were synaptophysin+, 8 (47%) were chromogranin A+, 8 (47%) were TTF1+, 7 (41%) were c-kit+, and 6 (35%) were CD44+. Strong patchy or strong diffuse p16 staining was seen in all cases. LOH and X-chromosome inactivation analysis were performed for 17 cases, 8 of which had a coexisting squamous or adenocarcinoma component. Five of the 8 (63%) cases with 2 components showed allelic loss in both components. All 5 of these cases demonstrated identical LOH between the neuroendocrine and squamous or adenocarcinoma components. Nonrandom X-chromosome inactivation was seen in the neuroendocrine and other components in 4 of the 8 cases. In all 4 cases the pattern of inactivation was identical between the 2 components. Cervical neuroendocrine carcinomas have features similar to other extrapulmonary neuroendocrine carcinomas, including expression of TTF1, c-kit, and CD44. Consistent staining for p16 is also seen. Concordant genetic alterations support common clonal origin for neuroendocrine carcinomas with a coexisting squamous or adenocarcinoma component.

Expression of Transcription Factors and Nuclear Receptors in Mixed Germ Cell-Sex Cord Stromal Tumor and Related Tumors of the Gonads.

In this study, we compare the expression of OCT4, SALL4, and TSPYL1 in mixed germ cell-sex cord stromal tumor (MGC-SCST) of either gonad to that of normal adult testis, classic and spermatocytic seminoma, intratubular germ cell neoplasia, unclassified, gonadoblastoma, and dysgerminoma to determine the entity or entities that most closely resemble MGC-SCST by immunohistochemistry of germ cells. The most useful transcription factor was OCT4. In addition, to its already described value in distinguishing germinoma and embryonal carcinoma from yolk sac tumor and in differentiating classic from spermatocytic seminoma, we found that OCT4 is useful in confirming or ruling out potential malignancy in MGC-SCST of either gonad. Expression of OCT4 in most ovarian MGC-SCSTs resembles that of dysgerminoma, whereas most testicular examples resemble that of spermatocytic seminoma and normal adult testis. Thus, most MGC-SCSTs of the ovary are potentially malignant, and corresponding tumors of the testis are mostly benign; however, exceptions likely can be detected by the use of OCT4, potentially leading to more appropriate clinical management in some cases. SALL4 is an underutilized transcription factor that is useful in distinguishing testicular MGC-SCST from sex cord stromal tumor, unclassified in those neoplasms where the germ cells are sparse or unevenly distributed. Compared with other transcription factors studied, TSPY and its congener TSPYL1 have little value in the assessment of germ cell tumors because of their relatively wide range of expression in normal adult testis and in germ cell tumors.

Perspectives on signet ring stromal cell tumor and related signet ring cell lesions of the gonads.

In this article, we discuss advances in our knowledge of the pathology of signet ring stromal cell tumor and related signet ring cell lesions of the ovary and a single case of signet ring stromal cell tumor of the testis. We divide ovarian signet ring cell lesions into 3 categories that reflect differences in their pathogenesis and histologic appearance. With 1 exception, all authentic cases of signet ring stromal cell tumor have been unilateral. Cases of ovarian signet ring stromal cell tumor from the literature can arise in 2 ways. The majority of cases arise multifocally from fibroma, whereas the remainder likely arise directly from the ovarian stroma. In difficult cases, immunocytochemistry provides improved diagnostic accuracy in distinguishing signet ring stromal cell tumor and its mimics from Krukenberg tumor. The most useful antibodies in this regard are epithelial membrane antigen and vimentin.

On the pathogenesis of sclerosing stromal tumor of the ovary: a neoplasm in transition.

Sclerosing stromal tumor (SST) is a distinctive benign ovarian stromal neoplasm first reported in 1973. Although its initial description supports its characterization as an ovarian stromal tumor, its exact pathogenesis remains uncertain. It is usually hormonally inactive, but occasional tumors are estrogenic or androgenic, and virilization can occur during pregnancy. We report 11 cases of SST, 6 of which were associated with another type or other types of ovarian stromal tumor. In 4 of these, a transition from thecoma of either typical or luteinized type to SST was observed. Our index case was that of a 16-yr-old girl who had a typical thecoma that underwent involutional changes in an extensive subserosal portion of the tumor with conversion to SST. In our series, 3 cases of SST underwent transformation to ovarian myxoma, one of which also contained a component of thecoma. The active SST components stained for inhibin, steroidogenic factor 1, and α-smooth muscle actin, but were negative or occasionally weakly positive for desmin.

Involuting luteinized thecoma of the ovary.

Spontaneous tumor involution in ovarian stromal tumors is a poorly understood phenomenon. In this report, we describe a rare case of luteinized thecoma that showed extensive involutional changes, such that cellular elements diagnostic of luteinized thecoma were sparse. The convoluted contour of the tumor resembled that observed in a corpus albicans; however, the neoplasm was considerably larger, and the contents of the nodule differed from that of a corpus albicans. The diagnosis of luteinized thecoma was established by the identification of residual aggregates of neoplastic theca cells and a nodule of lutein cells that were positive for inhibin and steroidogenic factor-1. Features of involution within the tumor included a few theca and lutein cells with pyknotic nuclei and abundant cytoplasmic lipid, occasional large adipocytes among the lutein cells, extensive hyalinization, dystrophic calcification, a myxohyaline nodule, and adipose metaplasia. It is likely that some of the aforementioned changes are the result of accompanying ischemia. Cleaved caspase-3 staining patterns were negative within residual lutein and theca cells; thus, we were unable to establish the occurrence of apoptotic bodies.

The pathogenesis of ovarian myxoma: a neoplasm sometimes arising from other ovarian stromal tumors.

Ovarian myxoma is a rare distinctive benign ovarian stromal neoplasm that occurs predominantly in young women and is hormonally inactive. Although typically classified as an ovarian stromal tumor, its exact pathogenesis remains uncertain. We report 4 cases of ovarian myxoma, 3 of which were associated with another type or other types of ovarian stromal tumor and 1 occurred as a pure myxoma. In 2 cases, the myxoma arose from a sclerosing stromal tumor, and the third, most likely arose from a luteinized theca cell tumor (LTCT). Myxoid transformation of the connective tissue of the parent neoplasm appears to be a precursor of ovarian myxoma in some instances. We believe that the occurrence of trisomy 12 or other genetic abnormalities may play a role in this transformation. Whether or not associated with another type of ovarian stromal tumor, ovarian myxoma can be suspected macroscopically by its cystic gelatinous appearance and sharp circumscription. The most important differential diagnosis is a low-grade sarcoma with myxomatous features. We believe that myxomas arising from different anatomic sites likely are genetically, histologically, and biologically distinct. For purposes of classification, they should be considered as separate tumor types.

Recurrent cotyledonoid dissecting leiomyoma of the uterus.

Cotyledonoid dissecting leiomyoma is a benign smooth muscle neoplasm with an unusual growth pattern that is characterized by intramural dissection within the uterine corpus and often a placental-like appearance macroscopically in its extrauterine component that may be alarming to the surgeon. All cases reported to date have been nonaggressive. We report a case in a 33-yr-old woman who had a history of prolonged uterine bleeding. She was operated upon for uterine leiomyomas, and the diagnosis of cotyledonoid dissecting leiomyoma was made at the time of intraoperative consultation. To maintain fertility, the intrauterine tumor was resected by myomectomy and the extrauterine tumor by excision. However, persistent uterine bleeding that eventually became intractable and continued growth of the neoplasm in the uterus necessitated hysterectomy 5 yr later. She was living and well 2.5 yr after hysterectomy with no evidence of disease.

Malignant Brenner tumor of the ovary with transformation to trabecular carcinoid: an immunocytochemical and electron microscopic study.

Ovarian Brenner tumors are typically of surface epithelial-stromal origin; however, cases associated with mature cystic teratoma and/or struma ovarii possibly have a teratomatous derivation. Although argyrophil cells have been described in ovarian Brenner tumors and in urinary bladder epithelium, we are not aware of any previous reports of carcinoid arising from a malignant Brenner tumor of the ovary. In this study, we describe an 85-year-old woman who had a low-grade malignant Brenner tumor with progressive proliferation of neuroendocrine cells and transformation to trabecular carcinoid as demonstrated by immunocytochemistry and electron microscopy.

Prevalence and management of fourth molars: a retrospective study and literature review.

PURPOSE: To evaluate the prevalence of fourth molars and determine if there are differences in occurrence with respect to gender, race, laterality, and site. PATIENTS AND METHODS: The charts and panoramic radiographs of all patients referred for third molar consultation between November 2008 and October 2010 at Misawa, US Air Base, Japan were reviewed and data collected included age, gender, and race. Inclusion criteria were minimum age of 18 years and no history of prior third molar surgery. If fourth molars were present, their number, location, size, and shape were noted. Patients with fourth molars were compared to patients without fourth molars with respect to gender and race. Percentages were calculated for laterality and site of occurrence as well. If differences were observed in these parameters, the χ(2) test was used to evaluate if the observed differences were statistically significant. RESULTS: Four hundred nine patients met the inclusion criteria and their charts and panoramic radiographs were reviewed. Fourth molars were observed in 2.2% of the patients. Their prevalence was slightly higher in males (2.2%) than in females (2.1%). They were notably more common in black patients (6.4%) than in whites (0.9%) (P < .005) and they presented more often in the maxilla (78%) than in the mandible (22%) but this difference was not statistically significant (P < .09). Most patients (55%) with fourth molars had them unilaterally. The maxillary fourth molars were typically peg-shaped and small, while the mandibular ones resembled miniature mandibular third molars. CONCLUSIONS: The prevalence of fourth molars in this population is 2%. They appear to be more common in black patients and tend to occur mostly in the maxilla unilaterally. When present, the decision to remove these supernumerary teeth should be based on a risk/benefit analysis similar to that of third molars.

Ovarian yolk sac tumors in older women arising from epithelial ovarian tumors or with no detectable epithelial component.

Yolk sac tumor (YST) occurs rarely in older women, either in association with a variety of ovarian epithelial tumors or, considerably less often, without an identifiable epithelial precursor. The patients often have elevated serum levels of α-fetoprotein that roughly correlate with the amount of the YST component. In postmenopausal women with an ovarian mass and elevated serum levels of α-fetoprotein, a tumor of this type should be suspected. Endometrioid carcinoma is the most common putative precursor, and the tumor is often associated with an endometriotic cyst; however, malignant Müllerian mixed tumor and mucinous neoplasms have also been reported as precursors. We report 4 cases of YST in postmenopausal women. Of the 3 cases with an identified epithelial component, 1 was serous carcinoma, another was clear cell adenocarcinoma, and the third was an admixture of endometrioid and clear cell adenocarcinoma arising from an endometriotic cyst. Although a precursor epithelial ovarian neoplasm, typically a malignancy (somatic carcinoma), is usually identified, no precursor neoplasm was observed in 1 of our cases and in 5 cases from the literature. We believe that YSTs in older women, whether or not an epithelial component is detected histologically, constitute a single entity that is distinct from YSTs in younger patients and should be treated aggressively. Neoplasms with a YST component in older women are less responsive to the chemotherapy currently used for ovarian germ cell tumors; therefore, adjuvant therapy should include platinum-based chemotherapy designed to treat both epithelial ovarian cancer and germ cell tumors. Of the 24 reported cases, including our own, 17 died of neoplasms within 25 months and another was living with disease at 2 months. However, 2 more recent patients treated aggressively with platinum-based chemotherapy designed to treat both epithelial and germ cell tumor components with stage 1 disease are living and have been disease free >1 year after operation.

Mixed germ cell-sex cord stromal tumour of the testis and ovary: comparison and contrast.

Mixed germ cell-sex cord stromal tumours (MGC-SCSTs) of the testis and ovary differ significantly in their histological appearance, clinical behaviour, and molecular genetics. Until recently, the germ cells of testicular MGC-SCST were considered to be invariably histologically bland, whereas those from neoplasms that arise in the ovary have histological features characteristic of premalignancy. However, a recent histological and molecular genetic study demonstrated histological abnormalities and multiple chromosomal losses and gains in a small subset of testicular cases, thus providing the first evidence that testicular MGC-SCSTs can exceptionally show histological and molecular abnormalities. All cases of testicular MGC-SCST reported to date have been clinically benign, whereas ovarian examples are sometimes the precursor of a malignant germ cell neoplasm that can be clinically aggressive. Both genetic and epigenetic influences likely account for dissimilarities in these uncommon gonadal neoplasms.

Gonadoblastoma: origin and outcome.

Classical gonadoblastoma occurs almost entirely in the dysgenetic gonads of an individual who has a disorder of sex development; however, a small number of cases arise in individuals with a normal peripheral karyotype and no evidence of a disorder of sex development. Those gonadoblastomas that occur in an individual who has a Y chromosome or part thereof express testis specific protein Y-encoded 1 (TSPY1). If a gonad in those individuals contains germ cells with delayed maturation and also harbors the TSPY1 gene, the cells can undergo transformation to classical gonadoblastoma. The latter consists of rounded islands composed of germ cells, sex cord elements, and hyaline basement membrane material surrounded by a variably cellular stroma that sometimes contains steroid cells. Classical gonadoblastoma can be interpreted as a noninvasive or an in situ neoplasm that is the precursor of germinoma in some individuals and, indirectly, of other more aggressive germ cell neoplasms. The "dissecting" variant is derived from classical gonadoblastoma and is characterized by unusual growth patterns. Undifferentiated gonadal tissue is the precursor of gonadoblastoma; however, if all germ cells in an individual with undifferentiated gonadal tissue involute, the result is a secondary streak gonad. Undifferentiated gonadal tissue is a non-neoplastic condition resembling a streak gonad but additionally contains germ cells with delayed maturation that express octamer-binding transcription factor 4; however, other germ cells, show normal maturation and express TSPY1.

Gonadoblastoma versus ovarian mixed germ cell-sex cord stromal tumor in women or girls with no evidence of a disorder of sex development: A problem in differential diagnosis.

Gonadoblastoma occurring in a normal girl or woman has been confused with ovarian mixed germ cell-sex cord stromal tumor (MGC-SCST) due to a lack of knowledge that the former occurs occasionally in a normal woman or girl. In this article, we develop histological criteria that facilitate the distinction of gonadoblastoma in an individual with a normal karyotype and no evidence of a disorder of sex development from ovarian MGC-SCST. We reviewed the histological findings of gonadoblastoma occurring in normal individuals and compared them to cases of ovarian MGC-SCST in our files. The histological findings of gonadoblastoma differ substantially from those of ovarian MGC-SCST. Importantly, gonadoblastoma contains two types of transformed germ cells, some histologically benign and others premalignant, whereas MGC-SCST contains only a single type, typically premalignant in the ovary and benign in the testis. Furthermore, degenerative changes of hyalinization and calcification are common in gonadoblastoma, whereas they are extremely rare in MGC-SCST. Although the great majority of cases of gonadoblastoma occur in an individual with a disorder of sex development and an abnormal karyotype, a substantial number arise in a normal woman or girl with no evidence of a disorder of sex development. In the latter circumstance, it is important to distinguish gonadoblastoma from ovarian MGC-SCST. It is very likely that those gonadoblastomas arising in a normal individual develop through a different molecular pathway than the ones that occur in the dysgenetic gonads of an individual with a disorder of sex development.

Achieving flexible competence: bridging the investment dichotomy between infectious diseases and cancer.

Today's global health challenges in underserved communities include the growing burden of cancer and other non-communicable diseases (NCDs); infectious diseases (IDs) with epidemic and pandemic potential such as COVID-19; and health effects from catastrophic 'all hazards' disasters including natural, industrial or terrorist incidents. Healthcare disparities in low-income and middle-income countries and in some rural areas in developed countries make it a challenge to mitigate these health, socioeconomic and political consequences on our globalised society. As with IDs, cancer requires rapid intervention and its effective medical management and prevention encompasses the other major NCDs. Furthermore, the technology and clinical capability for cancer care enables management of NCDs and IDs. Global health initiatives that call for action to address IDs and cancer often focus on each problem separately, or consider cancer care only a downstream investment to primary care, missing opportunities to leverage investments that could support broader capacity-building. From our experience in health disparities, disaster preparedness, government policy and healthcare systems we have initiated an approach we call flex-competence which emphasises a systems approach from the outset of program building that integrates investment among IDs, cancer, NCDs and disaster preparedness to improve overall healthcare for the local community. This approach builds on trusted partnerships, multi-level strategies and a healthcare infrastructure providing surge capacities to more rapidly respond to and manage a wide range of changing public health threats.