Mediastinal Parathyroid Carcinoma with Metastases

Reports of only 6 cases of functional parathyroid carcinoma with metastases could be found in the literature, and none of these arose in the mediastinum. Castleman (4), of the Massachusetts General Hospital, found 20 per cent of parathyroid adenomas to be mediastinal. In the files of the Armed Forces Institute of Pathology (1) there are no mediastinal parathyroid carcinomas and only one mediastinal parathyroid adenoma. The case presented here was first reported in a symposium on mediastinal tumors (3) as a mediastinal adenoma of the parathyroid gland. Subsequently recurrent mediastinal masses and symptoms developed, leading to the patient's death. On postmortem examination, the masses in the mediastinum, in addition to multiple metastatic areas, proved to be parathyroid carcinoma. Case Report A 46-year-old farmer was first seen in the Christie Clinic in September 1946 because of urinary frequency, dysuria, and fever. He had been subject to recurrent right flank pain since the age of thirty-two and in 1939 had been hospitalized for hematuria. Roentgenograms showed stones in the right renal pelvis and ureter, subsequently removed surgically. In 1940 a left nephrolithotomy was necessary. The patient convalesced rapidly on medical management, although the history at that time suggested the possibility of hyperparathyroidism. Neck exploration was refused. In August 1949, the patient was again in the hospital briefly, for recurrent urinary tract infection. A routine chest film demonstrated a huge anterior mediastinal mass extending well into the right hemithorax (Fig. 1). This was obviously asymptomatic and radiographically was interpreted as a benign tumor, dermoid cyst being given first consideration in diagnosis. Operation was undertaken on Nov. 17, 1949, disclosing a solid gray mass as large as a football, densely adherent to the medial aspect of the right lung and originating by a broad base in the upper anterior mediastinum. There were no local extensions, and removal, by sharp dissection, was apparently complete (Fig. 2). The gross pathological description was “a partially encapsulated lobulated mass 15.5 × 18 cm. in its greatest dimension… soft and friable in consistency. Areas of hemorrhage and necrosis are evident in the central portion. Strands of connective tissue divide the mass into lobules.” Microscopically, the section showed “interlacing cords of cells with closely spaced small, dark nuclei and poorly defined cytoplasm. There are numerous clear spaces in the masses, some containing mucin, others a small blood vessel. In general, the growth is orderly, but the cellularity and increased chromatin content of the nuclei indicate a very active tumor with possible low-grade malignant potential.” The pathological conclusions at this time showed a difference of opinion.