Applied Radiology

Diagnosis

Carney's triad

DIFFERENTIAL DIAGNOSIS

The large, calcified intrapulmonary masses could represent metastases from an osteogenic sarcoma or chondrosarcoma, multiple hamartomas, chondromas, amyloidomas, or, less likely, large granulomata. The ulcerating mass in the stomach fundus most likely represents a gastric adenocarcinoma, lymphoma, leiomyosarcoma or other stromal tumor, metastatic disease, or, less likely, an inflammatory process.

Findings

The frontal chest radiograph demonstrates several right-sided calcified lung parenchymal masses: the largest is at the right cardiophrenic sulcus, two others are located in the right paratracheal region, and a small lesion is seen superimposed on the third right anterior rib (figure 1A). The contrast-enhanced CT image through the basilar region of the thorax better demonstrates a large, homogeneously calcified mass with a lumpy, irregular border occupying a large part of the right lower lobe (figure 1B). The CT image through the upper abdomen demonstrates an irregular, ulcerating soft tissue mass in the posterior stomach wall (figure 2).

Discussion

In 1977, Carney described the triad of gastric epithelioid leiomyosarcoma, functioning extra-adrenal paraganglioma, and pulmonary chondroma.^1-3 The genetic and pathologic basis of the association is currently unknown. The three constituent entities themselves are relatively unusual, thus the triad is extremely rare. There is an approximately ten-fold female predominance. Due to the rarity of these tumors, the presence of any two of them is regarded as sufficient basis for making the diagnosis. The time interval between the appearances of the neoplastic lesions can be up to decades, and the tumors can appear in any order. Once the diagnosis is made, patients must be followed carefully in order to detect new lesions as early as possible, since two of the three entities have malignant potential. Gastric leiomyosarcoma is most likely to be present (~97%), followed by pulmonary chondroma (~83%) and paraganglioma (~53%). The complete triad is present in about 33% of cases. The overall mortality of the triad is approximately 20%.

Epithelioid leiomyosarcoma (also called malignant leiomyoblastoma) is one of the most indolent tumors known; however, it does have metastatic potential. Patients with an epithelioid leiomyosarcoma frequently present with anemia and severe upper gastrointestinal bleeding, abdominal pain, and a palpable abdominal mass. This entity usually has a milder clinical course when present within the context of Carney's triad than when it appears in isolation. The lesion is typically treated by wide resection and omentectomy.^4-6

Most paragangliomas are extraadrenal (~85%) and nonfunctional. The tumor is slow-growing but can be invasive and frequently involves vital structures. The tumor is metastatic in ~13% of cases. A functioning paraganglioma may manifest itself by sympathetic effects such as hypertension, diaphoresis, and/or facial flushing. A ¹³¹I-MIBG scan is useful for diagnosis, as this agent localizes to catecholamine-producing tissues. Since this lesion is potentially malignant, resection is necessary. Beta blockers should be administered preoperatively. If the lesion is unresectable, radiation and chemotherapy may be used.

Pulmonary chondromas are benign hamartomas, and are multiple in ~63% of cases. They are frequently mistaken for metastases. The diagnosis is established by excisional biopsy, or, if the triad is already established, by needle biopsy. If the pulmonary lesions display characteristic diffuse popcorn calcification, a radiographic diagnosis is possible. If the pathology is unequivocally benign, the patient can be followed radiographically.

1. Acha T, Picazo B, Garcia-Martin FJ, et al: Carney's triad: Apropos of a new case. Med Pediatr Oncol 22:216-220, 1994.
2. Argos MD, Ruiz A, Sanchez F, et al: Gastric leiomyoblastoma associated with extraadrenal paraganglioma and pulmonary chondroma: A new case of Carney's triad. J Pediatr Surg 28:1545-1549, 1993.
3. Carney JA, Sheps SG, Go VL, Gordon H:The triad of gastric leiomyosarcoma, functioning extraadrenal paraganglioma, and pulmonary chondroma. N Engl J Med 296:1517-1518, 1977.
4. Carney JA:The triad of gastric epithelioid leiomyosarcoma, functioning extraadrenal paraganglioma, and pulmonary chondroma. Cancer 43:374-382, 1979.
5. de Jong E, Mulder W, Nooitgedacht E, et al: Carney's triad. Eur J Surg Oncol 24:147-149, 1998.
6. Kiryu T, Kawaguchi S, Matsui E, et al: Multiple chondromatous hamartomas of the lung: A case report and review of the literature with special reference to Carney syndrome. Cancer 85:2557-2561, 1999.