Primary Retroperitoneal Carcinomas: New Insights into Pathogenesis and Clinical Management in Comparison with Ovarian Carcinomas and Carcinoma of Unknown Primary

Management of retroperitoneal high-grade serous carcinoma of unknown origin: A case report

BACKGROUND

Retroperitoneal high-grade serous carcinoma (HGSC) of unknown origin is a sporadic tumor that can originate from ovarian cancer. Herein, we report the case of a woman with retroperitoneal HGSC of unknown origin and describe how she was diagnosed and treated.

CASE SUMMARY

A 71-year-old female presented with the tumor marker CA125 elevated to 1041.9 U/mL upon a regular health examination. Computed tomography revealed retroperitoneal lymph node enlargement. Subsequently, positron emission tomography scanning revealed lesions with increased F-18 fluorodeoxyglucose uptake at the nodes. As a result, she underwent laparoscopic lymph node resection, and pathology revealed metastatic adenocarcinoma with CK7(+), PAX8(+), WT1(+), PR(-), and p53 mutational loss of expression, indicating that the origin may be from the adnexa. The patient was admitted to our ward and underwent laparoscopic staging; however, the pathological results were negative. Under the suspicion of retroperitoneal HGSC of unknown origin, chemotherapy and targeted therapy were initiated. Tumor marker levels decreased after treatment.

CONCLUSION

We present a case of HGSC of unknown origin managed using retroperitoneal lymphadenectomy, staging surgery, chemotherapy, and targeted therapy.

Metastatic Clear Cell Carcinoma of Unknown Primary Origin in an Elderly Female Patient With Paraneoplastic Hypercalcemia

Metastatic clear cell carcinoma (mCCC) is a rare histological subtype of cancer with ovarian and renal origins most common primary sites. Cancer of unknown primary origin (CUP) is a rare type of cancer in the United States and the most common histologic subtypes are adenocarcinoma, squamous cell cancer, and neuroendocrine cancer. We are presenting a rare case of an 86-year-old female patient with mCCC of unknown origin, biopsy and staining showed renal and ovarian in the differential of primary cancer type. However, the patient did not survive the aggressive nature of mCCC and was unable to get any trials of chemotherapy. Primary sites of adenocarcinoma of unknown origin are most common in the breast, lung, pancreas, prostate, colon, and liver. In most cases, empiric chemotherapy with platinum-based agents is the standard of care but needs more data to manage CUP, making it difficult to identify the primary site.