Deciphering tumour microenvironment and elucidating the origin of cancer cells in ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (CCC) has an East Asian preponderance. It is associated with endometriosis, a benign condition where endometrial (inner lining of the uterus) tissue is found outside the uterus and on the peritoneal surface, in the abdominal or pelvic space. CCC is relatively more resistant to conventional chemotherapy compared to other ovarian cancer subtypes and is associated with a poorer prognosis. In this study, we recruited and obtained tumour tissues from seven patients across the four stages of CCC. The tumour and the tumour microenvironment (TME) from 7 CCC patients spanning clinical stages 1-4 were transcriptionally profiled using high-resolution scRNA-seq to gain insight into CCC's biological mechanisms. Firstly, we built a scRNA-seq resource for the CCC tumour microenvironment (TME). Secondly, we identified the different cell type proportions and found high levels of immune infiltration in CCC. Thirdly, since CCC is associated with endometriosis, we compared CCC with two publicly available endometriosis scRNA-seq datasets. The CCC malignant cells showed similarities with glandular secretory and ciliated epithelial cells found in endometriosis. Finally, we determined the differences in cell-cell communication between various cell types present in CCC TME and endometriosis conditions to gain insights into the transformations in CCC.

Whole genome sequencing of HER2-positive metastatic extramammary Paget's disease: a case report.

BACKGROUND: Extramammary Paget's disease (EMPD) is a rare cancer that occurs within the epithelium of the skin, arising predominantly in areas with high apocrine gland concentration such as the vulva, scrotum, penis and perianal regions. Here, we aim to integrate clinicopathological data with genomic analysis of aggressive, rapidly-progressing de novo metastatic EMPD responding to HER2-directed treatment in combination with other agents, to attain a more comprehensive understanding of the disease landscape. METHODS: Immunohistochemical staining on the scrotal wall tumor and bone marrow metastasis demonstrated HER2 overexpression. Whole genome sequencing of the tumor and matched blood was performed. RESULTS: Notable copy number gains (log2FC > 0.9) on chromosomes 7 and 8 were detected (n = 81), with 92.6% of these unique genes specifically located on chromosome 8. Prominent cancer-associated genes include ZNF703, HOOK3, DDHD2, LSM1, NSD3, ADAM9, BRF2, KAT6A and FGFR1. Interestingly, ERBB2 gene did not exhibit high copy number gain (log2FC = 0.4) although 90% of tumor cells stained HER2-positive. Enrichment in pathways associated with transforming growth factor-beta (TGFß) (FDR = 0.0376, Enrichment Ratio = 8.12) and fibroblast growth factor receptor (FGFR1) signaling (FDR = 0.0082, Enrichment Ratio = 2.3) was detected. Amplicon structure analysis revealed that this was a simple-linear amplification event. CONCLUSION: Whole genome sequencing revealed the underlying copy number variation landscape in HER2-positive metastatic EMPD. The presence of alternative signalling pathways and genetic variants suggests potential interactions with HER2 signalling, which possibly contributed to the HER2 overexpression and observed response to HER2-directed therapy combined with other agents in a comprehensive treatment regimen.

Synchronous Bilateral Ovarian Mesonephric-like Adenocarcinomas with Separate Origins from High-Grade Mullerian Adenosarcoma and Endometriosis: Report of a Rare Case.

Mesonephric-like adenocarcinoma (MLA) of the ovary is a recently recognized, rare malignancy with aggressive clinical behavior, and is thought to originate from Mullerian epithelium with mesonephric transdifferentiation. Emerging evidence suggests that MLA may be classified as an endometriosis-associated neoplasm. The presence of a sarcomatous component within MLA is extremely rare, with common differential diagnoses including the spindle cell component of MLA, carcinosarcoma, as well as mixed Mullerian adenocarcinoma and adenosarcoma. Herein, we report a 58-year-old Chinese woman with bilateral ovarian solid-cystic masses. The left ovarian mass comprised a biphasic tumor with a predominantly high-grade sarcomatous component displaying heterologous mesenchymal differentiation, including liposarcoma, rhabdomyosarcoma and chondrosarcoma-like areas, with a null-type p53 expression. The epithelial component ranged from a bland appearance in areas diagnostic of adenosarcoma to a clearly invasive carcinoma, both with mesonephric-like phenotype, being negative for estrogen receptor, progesterone receptor, and Wilms' tumor 1, variably positive for paired box gene 8, GATA binding protein 3, and thyroid transcription factor 1, with a wild-type p53 expression. The differing p53 expression between the epithelial and sarcomatous elements mitigated against a diagnosis of carcinosarcoma. The right ovarian mass showed endometriosis with focal direct evidence of the development of malignancy within a benign endometriotic cyst, exhibiting the identical immunoprofile of MLA but originating as another malignancy. To the best of our knowledge, this case represents the first reported case of synchronous bilateral ovarian MLAs with separate origins, from high-grade Mullerian adenosarcoma and endometriosis respectively, which broadens the morphologic spectrum of MLA and provides further evidence supporting the Mullerian origin theory.

Penile melanosis with annular fibrillar pattern.

Penile melanosis is an uncommon but benign condition. Its appearance, however, can cause significant distress to patients. We report a case of a patient presenting with hyperpigmented annular penile macules, with a fibrillar pattern seen on dermoscopy. Histopathological examination revealed basal keratinocyte hyperpigmentation with no melanocytic proliferation or atypia, confirming our diagnosis of penile melanosis. The patient was managed conservatively. We also reviewed the literature surrounding the clinical assessment and management of penile melanosis. Future reports on this topic with clinical-dermoscopic-pathological correlations will aid further understanding of this seldom reported condition.

Acne agminata: dermoscopic features and a short review.

Acne agminata is a rare idiopathic inflammatory dermatosis. Treatment is variable with no clear consensus. We herein report a case of a 31-year-old man with sudden onset papulonodular eruptions on his face over two months. Histopathological examination revealed superficial granuloma composed of epithelioid histiocytes and scattered multinucleated giant cells, confirming acne agminata. Dermoscopy showed focal orangish structureless areas with follicular openings with white keratotic plugs. He achieved complete clinical resolution with oral prednisolone in 6 weeks. We also reviewed the literature regarding the reported treatment regimens used.

Surprise Lymph Node Histology in a Patient with Ovarian Serous Carcinoma.

We report a case of a sixty-three-year-old Chinese female with a known past history of primary, biopsy-diagnosed, ovarian high-grade serous carcinoma. Following three cycles of chemotherapy, she underwent total hysterectomy, bilateral salpingo-oophorectomy cytoreductive surgery with lymphadenectomy, and multiple peritoneal biopsies. In this situation, the lymph nodes would be expected to demonstrate possible residual metastatic serous carcinoma with or without chemotherapy effect. The final diagnostic assessment in the lymph nodes, in this patient, however, was a rare combination of the following pathologies: metastatic serous carcinoma, with areas of chemotherapy effect, and incidental PEComatosis, focally in association with endometriosis, both within lymph nodes and surrounding connective tissue. PEComas have been described in patients with the tuberous sclerosis complex, but the current patient was not known to suffer from this condition. This case is also unusual, as although PEComas have been described as arising in the female genital tract, the associated phenomenon of endometriosis is exceedingly rare, and this is the first known reported case of lymph nodes harbouring a similar combination of pathologies.

Cutaneous Presentation of Angioimmunoblastic T-Cell Lymphoma: A Harbinger of Poor Prognosis?

A 62-year-old woman presented with a 2-year history of extensive, pruritic dermatosis over her face, trunk, and limbs. She was initially treated for psoriasis with methotrexate 5 mg twice weekly and topical clobetasol cream; however, her condition worsened, and she was admitted for generalized exfoliative dermatitis. Examination showed generalized erythema and scaling affecting her face (Figure 1A), chest (Figure 1B), back, and limbs. There were also cervical, axillary, and inguinal lymphadenopathy. Laboratory studies revealed a high white blood cell count of 125×109/L (reference range: 4-10×109/L), hemoglobin level of 11.9 g/dL (reference range: 12-16 g/dL), and normal platelet level of 396×109/L (reference range: 140-440×109/L). Results from direct Coombs test were negative and lactate dehydrogenase levels were normal.

Characteristics and behaviour of screen-detected ductal carcinoma in situ of the breast: comparison with symptomatic patients.

Breast cancer is the most common malignancy in Singapore women. Ductal carcinoma in situ (DCIS) is the putative, non-obligate precursor of the majority of invasive breast cancers. The efficacy of the Singapore breast-screening pilot project in detecting early stage breast cancer led to the launch of a national breast-screening programme, BreastScreen Singapore (BSS), in January 2002. In this study, we compared clinicopathological and immunohistochemical characteristics, as well as clinical outcomes, between screen-detected and symptomatic DCIS. The study cohort comprised 1202 cases of DCIS diagnosed at Singapore General Hospital from 1994 to 2010. Comparison of clinicopathological parameters, immunohistochemical results of ER, PR, HER2, CK14, EGFR, and 34ßE12, and clinical outcomes was carried out between the 2 groups. Amongst 1202 cases, 610 (50.7%) were screen-detected and 592 (49.3%) were symptomatic DCIS. Screen-detected cases were smaller in size (P < 0.001), of lower nuclear grade (P = 0.004), and more frequently expressed ER (P < 0.001). Luminal A phenotype was more frequently observed in screen-detected DCIS, while triple-negative and HER2 phenotypes were more common in symptomatic DCIS (P < 0.001). The basal-like phenotype was also more frequent in symptomatic DCIS (P = 0.041). Mean and median follow-up was 99.7 and 97.8 months, respectively, with a maximum follow-up of 246.0 months. More symptomatic patients developed invasive recurrences compared to screen-detected patients (P = 0.001). A trend for better disease-free survival was observed in screen-detected patients (P = 0.076). Patients who were screen-detected experienced better overall survival than those with symptomatic DCIS (P = 0.007). Our data indicate a more favourable outcome of screen-detected DCIS patients confirming the role of BSS in early identification of this curable disease.

MED12 is frequently mutated in breast phyllodes tumours: a study of 112 cases.

AIM: To determine the frequency of MED12 mutations in a series of 112 breast phyllodes tumours, and to correlate the findings with clinicopathological parameters and survival outcomes. METHODS: Phyllodes tumours from the Department of Pathology, Singapore General Hospital, were classified into benign, borderline and malignant categories. Genomic DNA from formalin-fixed paraffin-embedded phyllodes tumours was extracted, purified and subjected to ultra-deep-targeted amplicon sequencing across exon 2 of the MED12 gene. Sequencing was performed on the Illumina MiSeq next-generation sequencing platform and bioinformatics analysis applied. Appropriate statistical analyses were carried out. RESULTS: There were 66 benign, 32 borderline and 14 malignant tumours, with 43 (65.1%), 21 (65.6%) and 6 (42.8%) disclosing MED12 mutations (missense, splice site, indel), respectively. For 97 cases with available follow-up, there were 10 (10.3%) recurrences. Patients with phyllodes tumours that harboured MED12 mutations experienced improved disease-free survivals, with higher recurrence likelihood in those without MED12 mutations (HR 9.99, 95% CIs 1.55 to 64.42, p=0.015). CONCLUSIONS: Similar to fibroadenomas, phyllodes tumours show a high frequency of MED12 mutations, affirming the close biological relationship between these fibroepithelial neoplasms.