Pulmonary pleomorphic carcinoma with multiple metastases to the right posterior knee complicated by paraneoplastic hypercalcemia.

In this report, we describe the case of a 46-year-old male who presented with a three-month history of progressive intermittent pain over the right posterior knee. Magnetic resonance imaging showed soft tissue masses over the right popliteal fossa. Surgery was performed, and histological examination revealed the mass to be a sarcomatoid carcinoma of poor differentiation. Fluorodeoxyglucose (FDG)-positron emission tomography showed FDG uptake in the lungs and in the right para-aortic and popliteal regions. On the basis of the morphological and immunohistochemical features of the specimens, the patient's condition was diagnosed as a pulmonary pleomorphic carcinoma with multiple metastases. Systemic chemotherapy was initiated with paclitaxel and cisplatin. The patient then developed paraneoplastic hypercalcemia and ultimately succumbed to healthcare-acquired pneumonia. The results of this rare case indicate that pulmonary pleomorphic carcinomas respond poorly to combination chemotherapy with paclitaxel and cisplatin. The firm mass in the popliteal fossa that was situated behind the knee was considered to be a Baker cyst; however, the possibility of malignant metastatic sarcomas, such as pulmonary sarcomatoid carcinoma, should be considered in the differential diagnosis. In conclusion, we emphasize that pretherapeutic examinations should be the basis for the diagnosis of a mass lesion at either an unusual or usual site.

Rapidly evolving asymptomatic eosinophilia in a patient with lung adenocarcinoma causes cognitive disturbance and respiratory insufficiency: Case report.

Paraneoplastic eosinophilia is an unusual manifestation that usually remains asymptomatic. In this report, we presented the case of an 82-year-old patient with poorly differentiated lung adenocarcinoma and asymptomatic eosinophilia. The patient's condition worsened rapidly over a week, with episodes of cognitive disturbance, shortness of breath and acute kidney dysfunction. These symptoms were associated with a 4-fold increase in circulating eosinophil counts. The poor condition hindered further anticancer treatment. Treatment of the eosinophilia with corticosteroids and hydroxyurea significantly reduced circulating eosinophil counts to below the initial levels. Results of this case report suggested that lung cancer patients should be monitored closely for rapidly worsening symptoms of cognitive disturbance and respiratory insufficiency as signs of life-threatening asymptomatic eosinophilia, in order to initiate corticosteroid treatment.