The most likely diagnosis in this patient is ovarian serous cystadenocarcinoma given the presence of psammoma bodies on tissue biopsy.
In this postmenopausal patient with bloating, early satiety, fatigue, and ascites, ovarian cancer should be high on the differential. The pelvic ultrasound confirms this suspicion by finding an ovarian mass. Ovarian tumors can be identified using serum markers or histology. In this case, the presence of psammoma bodies on tissue biopsy is highly specific for serous cystadenocarcinoma. Psammoma bodies are cancer cells that are dystrophically calcified and have the appearance of onion skin on histology. They are also seen in papillary thyroid cancer, meningioma, and mesothelioma.
Figure A demonstrates the classic histologic appearance of psammoma bodies. Note the onion skinning appearance and basophilic calcifications.
Answer 1: Serous cystadenoma is a benign proliferation of ovarian epithelial cells. It will generally show fallopian tube-like epithelium on histology and would not likely cause these systemic symptoms.
Answer 3: Mucinous cystadenocarcinoma is a malignant ovarian tumor of epithelial origin. It is unique in that it may present with intraperitoneal mucus accumulation (pseudomyxoma peritonei).
Answer 4: Mature teratomas (dermoid cysts) are germ cell-derived benign tumors of the ovary. They contain cells from multiple tissue types including teeth, hair, skin, etc.
Answer 5: Granulosa-theca cell tumors are sex cord stromal benign ovarian lesions that secrete estrogens, resulting in precocious puberty in children and endometrial hyperplasia in adults. Histology will demonstrate Call-Exner bodies, which are small follicles filled with eosinophilic secretions.
Psammoma bodies are concentric circular basophilic calcified structures. They are seen in papillary thyroid carcinoma, ovarian serous cystadenocarcinoma, meningioma, and mesothelioma.