Monoarticular carcinomatous knee joint arthritis as an initial presentation of cervical carcinoma.

When it comes to cancer, one can expect the unexpected. The clinical presentations can be very bizarre. One of these uncommon presentations is monoarticular arthritis. The age group affected by cancer and arthritis are similar. However, the possibility of joint pain being secondary to metastatic involvement does not come to mind easily. In this report, a 65-year-old postmenopausal woman presented with complaint of pain and restricted movement of the right knee joint, in whom the clinical and magnetic resonance imaging features were suggestive of infective monoarthritis. However, synovial fluid aspirate showed presence of malignant cells. Hence, patient was evaluated with whole-body (18)F-fluorodeoxyglucose positron emission tomography computed tomography which detected primary malignancy of the cervix with regional nodal and right knee joint metastasis. To our knowledge, this is the first reported case of cervical malignancy with solitary skeletal metastasis involving the knee joint. The report also discusses overall incidence of malignant arthritis.

Contrast-enhanced [18F] fluorodeoxyglucose-positron emission tomography-computed tomography as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin.

BACKGROUND: To evaluate the advantages of contrast enhanced F-18-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-contrast enhanced CT [CECT]) when used as an initial imaging modality in patients presenting with metastatic malignancy of undefined primary origin (MUO). MATERIALS AND METHODS: A total of 243 patients with fine needle aspiration cytology/biopsy proven MUO were included in this prospective study. Patients who were thoroughly evaluated for primary or primary tumor was detected by any other investigation were excluded from the analysis. Totally, 163 patients with pathological diagnosis of malignancy but no apparent sites of the primary tumor were finally selected for analysis. The site of probable primary malignancy suggested by PET-CECT was confirmed by biopsy/follow-up. RESULTS: PET-CECT suggested probable site of primary in 128/163 (78.52%) patients. In 30/35 remaining patients, primary tumor was not detected even after extensive work-up. In 5 patients, where PET-CECT was negative, primary was found on further extensive investigations or follow-up. The sensitivity, specificity, positive predictive value and negative predictive value of the study were 95.76%, 66.67%, 88.28% and 85.71% respectively. CONCLUSIONS: F-18 FDG PET-CECT aptly serves the purpose of initial imaging modality owing to high sensitivity, negative and positive predictive value. PET-CECT not only surveys the whole body for the primary malignancy but also stages the disease accurately. Use of contrast improves the diagnostic utility of modality as well as help in staging of the primary tumor. Although benefits of using PET-CECT as initial diagnostic modality are obvious from this study, there is a need for a larger study comparing conventional methods for diagnosing primary in patients with MUO versus PET-CECT.