Skin Metastasis of Low-Grade Ovarian Serous Carcinoma: A Case Report

This case report, written with the assistance of ChatGPT, describes a rare manifestation of ovarian serous carcinoma that metastasized to the skin. A 30-year-old female with a history of stage IV low-grade serous ovarian carcinoma presented for evaluation of a painful nodule on her back. Physical examination demonstrated a round, firm, mobile subcutaneous nodule on the left upper back. An excisional biopsy was performed, and histopathologic examination was consistent with metastatic ovarian serous carcinoma. This case highlights the clinical presentation, histopathology, and treatment of cutaneous metastasis of serous ovarian carcinoma. Additionally, this case highlights the value and technique of using ChatGPT to assist in writing medical case reports including outlining, referencing, summarizing studies, and formatting citations.


Introduction
Ovarian cancer is one of the leading causes of cancer deaths among women in the United States. Low-grade serous ovarian cancer (LGSC) is a rare type of epithelial ovarian cancer that accounts for approximately five percent of serous carcinomas and one to four percent of all ovarian carcinomas [1]. LGSC often exhibits aggressive behavior with a propensity for metastasis to the peritoneum and distant visceral organs. However, cutaneous metastasis of ovarian carcinoma is a rare phenomenon, occurring in less than two percent of cases, and even less common among the serous subtype of ovarian carcinoma. Here, we present a case of ovarian serous carcinoma that metastasized to the skin as a symptomatic nodule on the upper back.

Case Presentation
A 30-year-old female with a history of stage IV LGSC with known omentum, mesentery, large bowel metastases, and suspected lung involvement presented to the dermatology clinic for evaluation of a painful, growing nodule on her back. Physical examination revealed a round, firm, mobile subcutaneous nodule on the left upper back with intact overlying epidermis. The differential diagnoses included a cyst, fibroma, angiolipoma, or other cutaneous neoplasm.

Discussion
Cutaneous metastasis of ovarian cancer is rare, occurring in only approximately 0.9% to 4% of patients [2].
Skin metastases of serous ovarian carcinoma are even rarer, with only a handful of cases reported in the literature. A study of 206 patients with ovarian and fallopian tube carcinomas identified skin metastasis in just twelve cases, with only six of those exhibiting serous carcinomas [3]. In this case report, we highlight a rare case of metastasis of serous ovarian carcinoma to the skin. Given the rarity of cutaneous serous metastasis in ovarian cancer patients and the limited treatment options available, early detection and management are critical.
Ovarian carcinoma characteristically metastasizes to the umbilicus, often presenting as a periumbilical nodule, termed a "Sister Mary Joseph Nodule" (SJN), within primary surgical scars (surgical drains, laparoscopic scars), and other sites [3]. Clinically, non-SJN metastatic lesions may present as non-specific isolated or multiple painless dermal nodules. Other case reports describe large tumors presenting as sclerotic plaques or as hemangioma-like nodules [4].
A retrospective, single-institution study conducted by Otsuka and Matsuura found that 12 patients out of 206 diagnosed with ovarian carcinoma developed cutaneous metastases with 7 of the 12 patients demonstrating an SJN and three occurring within a primary incisional scar [3]. The exact mechanism of skin metastasis in ovarian cancer is not well understood. Proposed routes of SJN metastasis include hematogenous dissemination and direct extension from the peritoneal cavity or lymphatic spread [2]. The prognosis of cutaneous metastases in ovarian cancer is generally poor, with a median survival of one year [3]. The Ki-67 proliferative index can be assessed to determine the prognosis of ovarian carcinoma. A high Ki-67 proliferative index is positively correlated with a high mitotic activity, tumor grade, and stage of disease [5].
The most common dermoscopic findings found in a study that analyzed 20 cases of biopsy-proven cutaneous metastases were increased vascularity including serpentine and arborizing vessels [2]. Diagnosis of cutaneous metastases can also be confirmed by fine needle aspiration and incisional biopsy. In cases where the primary site of cancer is unknown, imaging studies such as computed tomography (CT) and positronemission tomography (PET)/CT scans can aid in diagnosis [2]. Recurrent skin metastases often do not require repeat biopsy or diagnostic evaluation as it does not change management.
The management of cutaneous metastases in ovarian cancer is challenging and depends on the location of metastatic lesions, patient comorbidities, and goals of care. SJS lesions may undergo surgical resection in conjunction with chemotherapy. For patients with non-SJS lesions, chemotherapy can be administered. In instances of concurrent visceral metastases and extensive skin metastases, palliative care can be considered to improve quality of life given that LGSC of the ovary is usually widespread by the time skin lesions appear. Palliative treatment options for skin metastases include surgical debulking or resection, chemotherapy, Mohs micrographic surgery, immunostimulatory agents, and external beam radiotherapy [2].
We used ChatGPT assistance in a variety of ways to write this case report including construction, referencing, summarizing studies, and formatting citations (Figures 3-5). We also used a special ChatGPT extension, WebChatGPT, in Google Chrome that allows ChatGPT to access internet data published after 2021 and recent studies and publications. WebChatGPT allows us to overcome the limitation of ChatGPT's default knowledge current to the date of 2021.