Characterization of the inflammatory infiltrate in ovarian dysgerminoma: an immunocytochemical study

Case Report: From epilepsy and uterus didelphys to Turner syndrome-associated dysgerminoma

Dysgerminoma is a rare occurrence in Turner syndrome patients without Y chromosome mosaicism or hormone therapy during puberty. We present a unique case of a 33-year-old nulliparous Chinese woman with intermittent epilepsy and Mullerian anomalies carrying a double uterus, cervix, and vagina. The patient is also characterized as having Turner syndrome accompanied by 46,X, del(Xp22.33-11.23) and del(2)(q11.1-11.2). MRI exhibited a 17.0 cm × 20.0 cm × 10.5 cm solid ovarian lesion. Radical surgery and pathology revealed dysgerminoma at stage IIIc with lymphatic metastases and a KIT gene mutation identified in exon 13. Furthermore, the tumor microenvironment (TME) displayed robust expression of CD4+ T lymphocytes and PD-1, whereas the distribution of CD8+ T lymphocytes and PDL-1 was sporadic. Despite the administration of enoxaparin to prevent thromboembolism, the patient experienced multiple cerebral infarctions during chemotherapy. Subsequently, the patient chose to decline further treatment and was discharged. This exceptional case imparts several noteworthy lessons. First, the coexistence of Mullerian anomalies, although rare, is not incompatible with Turner syndrome. Second, screening for KIT mutations is imperative to reduce the risk of dysgerminoma in Turner syndrome, especially for patients with Y mosaicism who are recommended for hormone replacement therapy. Lastly, comprehensive anticoagulation therapy is crucial for Turner syndrome patients undergoing cisplatin-based chemotherapy.

Molecular Pathways and Targeted Therapies for Malignant Ovarian Germ Cell Tumors and Sex Cord-Stromal Tumors: A Contemporary Review

Non-epithelial ovarian tumors are heterogeneous and account for approximately 10% of ovarian malignancies. The most common subtypes of non-epithelial ovarian tumors arise from germ cells or sex cord and stromal cells of the gonads. These tumors are usually detected at an early stage, and management includes surgical staging and debulking. When indicated for advanced disease, most respond to chemotherapy; however, options for patients with refractory disease are limited, and regimens can be associated with significant toxicities, including permanent organ dysfunction, secondary malignancies, and death. Targeted therapies that potentially decrease chemotherapy-related adverse effects and improve outcomes for patients with chemotherapy-refractory disease are needed. Here, we review the molecular landscape of non-epithelial ovarian tumors for the purpose of informing rational clinical trial design. Recent genomic discoveries have uncovered recurring somatic alterations and germline mutations in subtypes of non-epithelial ovarian tumors. Though there is a paucity of efficacy data on targeted therapies, such as kinase inhibitors, antibody–drug conjugates, immunotherapy, and hormonal therapy, exceptional responses to some compounds have been reported. The rarity and complexity of non-epithelial ovarian tumors warrant collaboration and efficient clinical trial design, including high-quality molecular characterization, to guide future efforts.

Ovarian clear cell carcinoma with plasma cell-rich inflammatory stroma: a clear cell carcinoma subgroup with distinct clinicopathological features

AIMS

Ovarian clear cell carcinoma has a unique stroma. Although a hyalinized or mucoid stroma is more common, the stroma sometimes shows a dense inflammatory infiltrate, simulating a dysgerminoma. The aim of this study was to analyse the character and significance of the inflammatory stroma.

METHODS AND RESULTS

Twelve of 60 (20%) clear cell carcinomas showed an inflammatory stroma. The inflammatory stroma and hyalinized/mucoid stroma were mutually exclusive. Inflammatory cells were predominantly composed of CD138-positive plasma cells. As compared with the non-inflammatory cases, the epithelial component frequently showed a solid growth pattern and immunoreactivity for cyclooxygenase-2, one of the critical proinflammatory enzymes (P < 0.005). These findings were repeated after heterotransplantation of three clear cell carcinoma cell lines into athymic nude mice. In particular, xenografts of one cell line (JHOC-5) were infiltrated by mature plasma cells, indicating that plasma cell differentiation was stimulated by JHOC-5 cells, independently of T lymphocytes. Clinicopathologically, the frequency of International Federation of Gynaecology and Obstetrics stage III was higher in the cases with an inflammatory stroma than in those without it (P < 0.01).

CONCLUSIONS

Clear cell carcinomas with an inflammatory stroma constitute a distinct clinicopathological subgroup. It is strongly suggested that tumour cells themselves are responsible for inducing inflammation and stimulating plasma cell differentiation in a paracrine manner.

Increased expression of 25-hydroxyvitamin D-1alpha-hydroxylase in dysgerminomas: a novel form of humoral hypercalcemia of malignancy

Humoral hypercalcemia of malignancy (HHM) is a common paraneoplastic disorder usually associated with increased synthesis of parathyroid hormone-related peptide (PTHrP). Unlike non-cancer forms of hypercalcemia, HHM does not routinely involve increased circulating levels of the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). Dysgerminomas are a notable exception to this rule, previous reports having described hypercalcemia with elevated serum 1,25(OH)2D3. To investigate the etiology of this form of HHM we have characterized expression and activity of the enzyme that catalyzes synthesis of 1,25(OH)2D3, 25-hydroxyvitamin D-1alpha-hydroxylase (1alpha-hydroxylase), in a collection of 12 dysgerminomas. RT-PCR analyses indicated that mRNA for 1alpha-hydroxylase was increased 222-fold in dysgerminomas compared to non-tumor ovarian tissue. Parallel enzyme assays in tissue homogenates showed that dysgerminomas produced fivefold higher levels of 1,25(OH)2D3 compared to normal ovarian tissue. Immunolocalization studies indicated that 1alpha-hydroxylase was expressed by both tumor cells and by macrophages within the inflammatory cell infiltrate associated with dysgerminomas. The immunological nature of the increased 1,25(OH)2D3 production observed in dysgerminomas was further emphasized by correlation between expression of 1alpha-hydroxylase and the endotoxin recognition factors CD14 and toll-like receptor 4 (TLR4). These data suggest that inflammatory mechanisms associated with dysgerminomas are the underlying cause of the increased expression and activity of 1alpha-hydroxylase associated with these tumors. We further postulate that this autocrine/paracrine action of 1alpha-hydroxylase may lead to increased circulating levels of 1,25(OH)2D3 and a form of HHM which is distinct from that seen with PTHrP-secreting tumors.

Tumour responding accessory cells in testicular seminoma: an immunohistochemical study

AIM

To investigate the role of accessory cells (and other chronic inflammatory cells) in the host immune response to testicular seminoma by defining their immunophenotypic characteristics and topographical arrangement.

METHODS AND RESULTS

A panel of antibodies applicable to paraffin-embedded tissues was employed to characterize the host chronic inflammatory response in eight cases of classical testicular seminoma. The antibodies were directed against CD45RO, CD20, CD68, acid cysteine proteinase inhibitor (ACPI), MAC387, muramidase (MUR), S100 protein, Factor XIIIa, CD21 and HLA Class II. In all cases the majority of the inflammatory cells were T-lymphocytes situated mainly in areas of apparent tumour destruction. Large numbers of macrophages/dendritic cells which had not been evident by conventional light microscopy were also demonstrated. In particular, an immunophenotypically distinct population of accessory cells showing a specific pattern of distribution was revealed. It clearly rimmed islands of tumour and showed strong positive staining for CD68, MAC387 and HLA Class II.

CONCLUSION

The study has identified an immunophenotypically distinct population of accessory cells showing a characteristic topographical arrangement. It is proposed that it represents a subpopulation of macrophages which are responding directly to the tumour and are likely to play a part in influencing tumour dynamics.