Introduction

About 30-50/100.000 women per year are diagnosed with ovarian cancer and half of the deaths related to female genital system malignancies are attributed to ovarian cancer (1). The most common histologic type of ovarian cancer is epithelial, and the most common subtype of epithelial cancer is serous adenocarcinoma. More indolent forms also exist that are no longer considered as malignant (2). The presence of microcalcifications in the primary tumor and although less common, in metastatic lesions, have been described in the literature (3,4). In cases of serous papillary cancer, the calcifications can be related to psammoma bodies’ deposits (3,4). Calcification deposits depicted at computed tomography (CT) are more often attributed to benign conditions. Moreover, calcifications in the already identified malignant lymph nodes are considered as response to chemo and/or radiotherapy (5,6,7). However, calcified lymph nodes, even in the presence of extensive calcification, may be active and should not be ignored (3). The role of fludeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in restaging, evaluating therapy response in ovarian cancer, as well as its impact on management decisions for the patients is well-described and has been reviewed (1,8). Attenuation uncorrected images should be reviewed in order to avoid misinterpretation of calcifications. This case presentation demonstrates the utility of FDG-PET/CT in the evaluation of residual disease in large calcified lymph nodes in a patient who underwent chemotherapy for recurrent serous adenocarcinoma of the ovaries, 18 years after the initial diagnosis.

Case Report

A 56 year-old woman had been treated 18 years ago for ovarian cancer. The patient underwent hysterectomy along with surgical removal of the fallopian tube and ovaries due to cancer of the right ovary. Histologic examination was consistent with well-differentiated serous papillary cystadenocarcinoma of the right ovary with scattered moderate differentiation, and metastatic invasion of the left ovary. Eighteen years later, the patient presented with a mass at the left supraclavicular space, corresponding to an enlarged lymph node. The fine needle aspiration biopsy (FNAB) of the enlarged supraclavicular lymph node revealed recurrence of the previously treated serous adenocarcinoma. Epithelial cells of cylindrical shape in papillary clusters, psammoma bodies and foamy histiocytes were observed. The patient underwent CT of the neck, thorax, upper and lower abdomen for evaluation of disease extent. Lymph nodes were detected at the neck, including the left supraclavicular area, the mediastinum, the left axilla, the right paraaortic region, the right common iliac and external iliac vessels, as well as the right retrocrural space. The lymph nodes were enlarged and displayed large amount of calcifications, while some of them were completely replaced by calcium depositions (Figure 1). The patient underwent chemotherapy with Taxol and Cisplatin (every 21 days) for three cycles, and Taxol and Carboplatin for the remaining three cycles, and was referred for evaluation of response to treatment. The CT revealed size reduction in the lymph nodes with progression of calcification at the previously described sites, with a density reaching up to ~900 HU in the calcified lymph nodes (Figure 2). The patient was referred for PET/CT examination for investigation of residual disease at the described lymph nodes and evaluation of treatment response six weeks after the last chemotherapy session. 50 minutes after intravenous administration of 362 MBq 18F-FDG, the PET/CT examination was performed by a Siemens Biograph LSO 16 sections device. Images were reconstructed at three levels, were corrected for attenuation and finally fused. Interpretation of PET/CT images was carried out by two experts (one nuclear medicine physician and one radiologist). Both corrected and uncorrected images were reviewed. Attenuation corrected FDG-PET/CT revealed hypermetabolism in all the described calcified lymph nodes, with a SUVmax ranging from 4.6 to 12.7, average SUVmax 8.78 (Figure 3). Uncorrected images also revealed active metabolic sites at all the described lymph nodes (Figure 4). The patient was referred for radiation treatment of the supraclavicular lymph node and was planned for close surveillance. On follow-up CT scans, additional calcifications were recognized in both the supraclavicular and the other lymph nodes. Follow-up fine needle aspiration of the still enlarged supraclavicular lymph node revealed metastasis from the known primary ovarian cancer, and the Magnetic Resonance Imaging revealed presence of another mass lesion of 5x3.5x3 cm size, which extended to the left axillary cavity. The patient underwent surgical removal of the supraclavicular lymph node and biopsy confirmed the diagnosis of metastasis and underlying multiple psammoma body deposits. After six months, the whole body CT revealed disease progression with multiple calcified lymph nodes as well as peritoneal implantation. A biopsy of the recently detected intra-tracheal mass confirmed the presence of new metastatic sites and moreover the presence of psammoma bodies. Based on the retrospective evaluation of patient’s medical history, these calcifications were interpreted as psammoma bodies formations, which was also consistent with the more indolent course of the patient’s disease.

Literature Review and Discussion

Conclusion

In conclusion, our case presentation has several remarkable characteristics. First, this case represents an ovarian serous carcinoma relapse after an 18-year disease-free interval. Second, it displays large calcified lymph nodes with increased density on CT images, which exhibit high FDG uptake in both attenuation corrected and uncorrected images, the last being evidence that increased FDG uptake is not an artifact. The formation of psammoma bodies could be suggested as a probable cause of calcification in this presented case. Similar to a previously described case, all sites of increased metabolic activity were considered as active tumor sites in the end.

Ethics

Informed Consent: All authors have filled in the informed consent.

Peer-review: External and Internal peer-reviewed.

Authorship Contributions

Surgical and Medical Practices: Vassilios Prassopoulos, Athanasios Alexopoulos, Roxani Efthymiadou, Fani Vlachou, Ioannis Andreou, Vassiliki Filippi, Vassiliki Rapti, Concept: Vassilios Prassopoulos, Athanasios Alexopoulos, Roxani Efthymiadou, Alexandra Nikaki, Design: Vassilios Prassopoulos, Athanasios Alexopoulos, Roxani Efthymiadou, Alexandra Nikaki, Data Collection or Processing: Vassilios Prassopoulos, Alexandra Nikaki, Athanasios Alexopoulos, Vassiliki Rapti, Analysis or Interpretation: Alexandra Nikaki, Athanasios Alexopoulos, Konstantinos Dalianis, Konstantinos Gogos, Literature Search: Alexandra Nikaki, Athanasios Alexopoulos, Vassilios Prassopoulos, Roxani Efthymiadou, Fani Vlachou, Vassiliki Rapti, Writing: Alexandra Nikaki, Prassopoulos Vassilios, Athanasios Alexopoulos, Roxani Efthymiadou.

Conflict of Interest: No conflict of interest was declared by the authors.

Financial Disclosure: The authors declared that this study has received no financial support.