No abstract

The clinical and pathologic features of 283 patients with thymoma treated at the Mayo Clinic (147 female and 136 male; ages 16 years to 90 years; mean, 52 years) were examined. Forty-six percent of the patients had myasthenia gravis and 10% had other paraneoplastic phenomena. The tumors were locally invasive at operation in 32%, including 6% with metastasis to lung or pleura. Intrathoracic recurrence was noted postoperatively in 15% of those who had total excision and distant metastasis developed in 3% of patients. Thirteen percent died of their thymomas and 16% died of myasthenia. Overall 5-year survival was 67% and 10-year survival was 53%. Poor prognostic factors included presence of tumor-related symptoms, large tumor size, local invasion or metastasis in initial operation, and predominantly epithelial histologic features. Although true thymomas are composed of cytologically benign elements, they show a propensity for local invasion and intrathoracic recurrence. They rarely metastasize outside the thorax.

The prognosis for SDC is dismal, and clinically useful prognostic factors were not found. Our results do not confirm hormonal concordance between SDC and breast carcinoma.

Sarcomas of the sinonasal region are rare. We describe a distinct spindle cell sarcoma of the sinonasal region characterized by concomitant neural and myogenic differentiation. Consultation files and surgical cases from Mayo Clinic were reviewed. Twenty-eight cases were identified that met the inclusion criteria. Clinical data were collected from medical records, consultation letters, and referring pathologists. Reverse transcriptase-polymerase chain reaction for synovial sarcoma fusion transcripts was performed on 18 cases. Cytogenetic studies were performed on 2 cases. The 21 female and 7 male patients ranged in age from 24 to 85 years (mean, 52 y). All cases showed a characteristic histology, which included a cellular spindle cell neoplasm with uniform, elongate nuclei and an infiltrative growth pattern. All tumors demonstrated expression of S-100 with actin positivity in 96% of cases tested. Reverse transcriptase-polymerase chain reaction for synovial sarcoma fusion transcripts was negative in all cases tested. Cytogenetic studies conducted on 2 cases demonstrated the chromosomal translocation t(2;4). The nasal cavity (54%) and ethmoid sinus (57%) were the most commonly involved areas, singly or in combination. Follow-up information was available for 57% (16/28) of cases, with a mean of 8.3 years. Of these, 44% (7/16) experienced at least 1 recurrence. No patient has developed metastases or died of disease. We describe a unique tumor with a characteristic morphologic, immunophenotypic, and cytogenetic profile. On the basis of the locally aggressive nature of this lesion we believe it is best considered a low-grade sarcoma and suggest the term low-grade sinonasal sarcoma with neural and myogenic features.

Important prognostic factors include tumor size, grade, and clinical and pathologic stage. Patients with minimally invasive tumors (<5 mm) should do well with appropriate surgical treatment.