Ovarian squamous cell carcinoma

Ovarian squamous cell carcinoma (oSCC) or squamous ovarian carcinoma (SOC) is a rare tumor that accounts for 1% of ovarian cancers. Included in the World Health Organization's classification of ovarian cancer, it mainly affects women above 45 years of age. Survival depends on how advanced the disease is and how different or similar the individual cancer cells are. Squamous ovarian carcinoma is a recognized but uncommon diagnosis, often originating from a transformation of mature cystic teratoma (MCT). Unlike other squamous cell carcinomas, factors like UV exposure and tobacco use play a less significant role. Chronic inflammation in MCT and human papillomavirus (HPV) infection are linked to its development. The tumor emerges through metaplasia of the ovarian surface epithelium. While MCT is the primary source in most cases, others are associated with endometriosis or Brenner tumor, and rare metastasis from other organs can also lead to squamous ovarian carcinoma. Treatment for oSCC involves surgery, chemotherapy, and radiotherapy, but efficacy of these treatments is unclear. While there is no well-studied chemotherapy regimen for ovarian SCCs, platinum-based chemotherapy is often used. The earliest reported instance of pure primary SCC was by Ben-Baruchet in 1988; oSSC emerging from pre-existing lesions have been recorded since the early 1950s.

Pathology

Mature cystic teratoma

Mature cystic teratoma (MCT) is a benign (non-cancerous) tumor that develops from at least two of the embryonic germ cell layers. They are characterized by a lining of epithelium and can contain many different tissue types. Although the majority of MCT cases are non-malignant, approximately 0.17-2% may undergo malignant transformation, with squamous cell carcinoma being the most prevalent, constituting 80% of such transformations. The clinical presentation of oSCC development within MCT lacks specificity, often resulting in the inadvertent discovery of early-stage tumors during routine examinations or postoperative assessments. In advanced cases, patients may exhibit palpable masses, abdominal swelling, and pain, potentially leading to acute abdominal complications due to tumor involvement.

Brenner tumor

Brenner tumors (BT) are infrequent ovarian growths composed of specialized ovarian cells surrounded by dense fibrous tissue. Typically small (less than 2 cm), these tumors are often discovered incidentally in women without apparent symptoms. However, when a BT is borderline or malignant, indicating a potential for cancer, it may lead to symptoms such as an abdominal lump, abdominal pain, and post-menopausal bleeding. Less common signs include nausea, vomiting, back pain, bowel problems, reduced appetite, and weight loss. Differentiating between benign (non-cancerous) and malignant (potentially cancerous) BTs poses a challenge as they appear similarly in medical images. The definitive diagnosis involves examining tissue under a microscope (histopathology). Benign BTs exhibit a consistent fibrous structure, a distinctive characteristic. They may also manifest as a cystic mass with multiple compartments, particularly associated with other ovarian growths.

Endometriosis oSCC tumors from endometriosis are rare. There are criteria to determine if oSCC comes from endometriosis. Individuals with this type of cancer are usually under 50, have a more severe form of the disease, and often feel abdominal pain.

Screening and diagnosis Similar to other ovarian cancers patients can undergo a series of tests to identify characteristics and/or markers. This test includes a pelvic exam, imaging (CT, MRI, ultrasound), blood test, and in some cases biopsy with histopathology. Diagnosing this condition remains challenging as preoperative imaging and laboratory tests lack specific indicators.

Computed tomography

Computed tomography (CT) scans is a diagnostic x-ray procedure that generates detailed cross-sectional images of the body, facilitating the detection of potential ovarian cancer spread to other organs. While CT scans may not effectively visualize small ovarian tumors, they have the capability to detect larger tumors and evaluate their potential invasion into nearby structures. Additionally, CT scans can identify enlarged lymph nodes, signs of cancer spreading to the liver or other organs, and indications of an ovarian tumor impacting the kidneys or bladder. Although CT scans are not commonly used for biopsying ovarian tumors, they can be utilized in the biopsy of suspected metastases through a technique known as CT-guided needle biopsy. The difficulty in screening for SCC revolves around the creation of effective strategies with a positive predictive value. The timing aspect is crucial due to the lack of a specific timeframe for the onset of invasive disease or the interval stage between stage I and stage III carcinomas. Ultrasound screening provides a detailed view of the ovaries, identifying morphologic changes as potential signs of malignancy. Key diagnostic factors include the presence of abnormalities, ovarian size, blood flow, and abdominal/pelvic fluid. The persistence of abnormalities after four to six weeks may decrease the occurrence of false positives. Screening protocols, often based on morphologic indices, utilize transvaginal ultrasound findings like cyst wall structure, septation, papillary projections, echogenicity, and ovarian volume to effectively detect malignancy.

Magnetic resonance imaging Although magnetic resonance (MRI) scans are not commonly employed for ovarian cancer detection, the majority of ultrasound-detected ovarian masses are usually benign. The combined approach of ultrasound with Doppler, along with the selective use of contrast-enhanced MRI, proves to be an efficient diagnostic method for identifying benign adnexal masses with distinctive features, including functional masses, dermoid, endometrioma, fibroma, pedunculated fibroid, hydrosalpinx, and peritoneal inclusion cysts. This integrated diagnostic strategy is effective in preventing unnecessary surgical intervention. Additionally, the use of MRI contributes to a decrease in false-positive diagnoses, ultimately reducing the overall number of unnecessary surgical procedures related to ovarian masses.

Histopathology

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