Diffuse sclerosing variant of papillary thyroid carcinoma: case report and review of the literature.

OBJECTIVE

To describe a patient with a diffuse sclerosing variant of papillary (DSVP) thyroid cancer and to summarize the reported clinical manifestations and treatment of other patients with this malignant tumor.

METHODS

We reviewed the pathologic findings in a 14-year-old girl, who had survived for 19 years after treatment of a presumed undifferentiated thyroid cancer. When reassessment revealed histologic features of DSVP cancer, we reviewed the case reports of this type of malignant lesion identified from a MEDLINE search of articles published between 1985 and 1995.

RESULTS

Review of the pathologic features showed a diffuse tumor in the thyroid gland without an identifiable mass and extensive bilateral lymph node metastatic lesions. Histologic examination disclosed pronounced fibrosis, numerous psammoma bodies, primarily a solid growth pattern, lymphocytic infiltration, and extensive invasion of lymphatic spaces. The nuclear features were characteristic of papillary carcinoma. Review of 63 cases of DSVP cancer indicated that this variant accounted for 0.2 to 5.7% of papillary cancer, affected primarily young women, and usually manifested with diffuse involvement of one or both thyroid lobes. Thyroid antibodies were frequently detected in the serum. Cervical lymph node metastatic lesions, local invasion, and distant metastatic involvement were described in 75, 35, and 16% of patients, respectively. Although the cancer recurred in 37% of patients, only two died of this malignant tumor.

CONCLUSION

DSVP cancer can be confused with nontoxic goiter, chronic thyroiditis, nonthyroidal malignant tumors, or undifferentiated thyroid cancer. We suggest that the same therapy used for young patients with conventional papillary thyroid cancer is also appropriate for most patients with the diffuse sclerosing variant.