|Micrograph of serous carcinoma, a type of serous tumour.|
Serous tumours are part of the surface epithelial-stromal tumour group of ovarian neoplasms, which derive from Mullerian epithelium. They are common neoplasms with a strong tendency to occur bilaterally, and they account for approximately a quarter of all ovarian tumors.
The "low grade" classification of serous tumors includes benign and borderline tumors, as well as low grade malignant tumors. Benign serous tumors are distinguished from borderline tumors by the absence of cellular stratification. Stromal invasion distinguishes borderline tumors from low grade malignant tumors. Surgery is curative for benign tumors, and likely curative for other low grade tumors.
Benign serous tumors include serous cystadenomas, cystadenofibromas, and adenofibromas. Benign and borderline serous tumours are commonly unilocular. Benign tumors contain clear fluid and have a smooth lining composed of columnar epithelial cells with cilia. On gross examination, the serous tumor may present as either a cystic lesion in which the papillary epithelium is contained within a few fibrous walled cysts, or the papillary projections may be away from the surface epithelium.
In borderline lesions, the cyst or surface is lined by papillary structures, which are often very complex. Microscopically, stromal papillae are covered by atypical epithelial cells, but stromal invasion is absent, and nuclear stratification is present. Approximately 15% of serous tumors are borderline.
High grade serous tumors often involve both ovaries. The tumors are solid and cystic with haemorrhage and necrosis. They are morphologically heterogenous. Serous carcinomas often have bulky peritoneal and omental metastases, and spread to the lymph nodes is frequent.
Unsurprisingly, 5-year survival decreases as the stage increases. There is a 25% survival rate with a stage III serous carcinoma. Staging:
- Stage I - Tumour growth limited to ovaries.
- Stage II - Growth involving one or both ovaries with pelvic extension.
- Stage III - Tumour involving one or both ovaries with implants outside pelvis.
- Stage IV- Tumour involving one or both ovaries with presence of distant metastasis.
- Rosai and Ackerman's Surgical Pathology (11 ed.). Elsevier. pp. 1367–1431.
- Kumar, Vinay. Robbins and Cotran Pathologic Basis of Disease (9 ed.). Elsevier. pp. 991–1042.