Thyroid and Parathyroid Neoplasms with Lipomatous Stroma: Report of Three Cases and Review of the Literature

Introduction/Objective

Tumors with mixed adipose tissue and epithelial components are rare in thyroid and parathyroid glands. Most of them are benign and referred to as adenolipoma (or lipoadenoma). A handful of malignant tumors of thyroid follicular cell origin have been reported with abundant adipose tissue known as thyroid carcinoma with lipomatous stroma (TCLS). Adenolipomas of thyroid or TCLS are usually manifested as large thyroid nodules and evaluated by fine needle aspiration biopsy (FNAB) which frequently yield low-cellularity samples due to abundant adipose tissue. On FNAB, the adipose tissue usually interpreted as contamination of subcutaneous or perithyroid origin. Similarly, adenolipomas of the parathyroid are not frequently identified because of presence of adipose tissue which is a feature associated with normal parathyroid glands. Therefore, these tumors are not often correctly diagnosed preoperatively. For that reason, pathologist should report additional cases about this rare entity to increase our understanding and to decrease preoperative diagnostic error.

Methods

We report three cases of thyroid and parathyroid tumors with abundant adipose tissue with sonographic, cytologic and histologic features along with literature review.

Results

Among the reported cases in the literature and our cases; 10 out of 17 cases of thyroid carcinoma with lipomatous stroma are papillary thyroid carcinomas (58.8%), 3 out of 17 cases are papillary microcarcinomas (17.6%), 2 out of 17 cases are noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) (11.7%), and 2 out of 17 cases are minimally invasive follicular carcinomas (11.7%). No cases of poorly differentiated or anaplastic thyroid carcinomas have been reported.

Conclusion

Lipomatous stroma in thyroid carcinoma appears to be associated with differentiated carcinomas since no reported cases of poorly differentiated or anaplastic thyroid carcinomas are present to our knowledge. Although the presence of fatty tissue does not appear to alter the prognosis of these lesions, the question of the histogenesis of the adipose component is intriguing. Awareness of this unusual feature and increased utilization of multimodal approaches in the evaluation of this entity may increase preoperative detection and the understanding of the histogenesis and its possible significance.

Pathogenesis of amyloid formation in Alzheimer's disease, Down's syndrome and scrapie

Paired helical filaments (PHF) are abnormal fibrous structures found in human nerve cells and their processes. Ultrastructural studies of the proto-filaments that make up the PHF revealed that the individual proto-filaments have a different substructure from normal neurofilaments or any other known fibrous profiles. Studies using immunological and biochemical methods suggested that abnormally phosphorylated tau, ubiquitin and neurofilament peptides are part of the PHF. Deposits of amyloid fibres in Alzheimer's disease and senile dementia of the Alzheimer type (AD/SDAT) are found in meningeal and brain vessels, choroid plexus and neuritic plaques. In 1984 Glenner and Wong reported the sequence of a beta-protein isolated from cerebrovascular amyloid. We used the amino acid sequence of the cerebrovascular amyloid protein to synthesize oligonucleotide probes specific for the gene encoding this amyloid protein. Screening of a human brain cDNA library allowed us to isolate a clone which encodes the amyloid peptide. In situ hybridization studies and Southern blot analysis of a DNA sample isolated from a human-mouse hybrid cell line indicated that the corresponding genomic sequences of this cDNA clone are located on human chromosome 21. Using immunochemical and histochemical methods, we have identified the cells associated with the formation of the amyloid fibres. With immunochemical and biochemical methods we and others also showed that the protein constituting amyloid in AD/SDAT is different from amyloid in unconventional slow virus diseases.

Treatment of recurrent glioblastoma multiforme using fractionated stereotactic radiosurgery and concurrent paclitaxel

Despite the progress in neurosurgery and radiotherapy, almost all patients treated with malignant gliomas develop recurrent tumors and die of their disease. Eighty-eight patients (median age 56 years) with recurrent glioblastoma (median tumor volume 32.7 cm3) were treated with noninvasive fractionated stereotactic radiosurgery and concurrent paclitaxel used as a sensitizer. The median interval between diagnosis of primary glioblastoma and salvage radiosurgery was 7.8 months. Four weekly treatments (median dose: 6.0 Gy) were delivered after the 3-hour paclitaxel infusion (median dose: 120 mg/m2). Survival was calculated by the Kaplan-Meier method from radiosurgery treatment. Overall median survival was 7.0 months, and the 1-year and 2-year actuarial survival rates were 17% and 3.4%, respectively. When grouped by performance status, there was no difference in survival between the patients with low and high Karnofsky score. Patients with tumor volume less than 30 cm3 survived significantly longer than those with tumor greater than 30 cm3 (9.4 vs. 5.7 months, p = 0.0001). Their 1-year survival rate was 40% and 8%, respectively. Eleven patients (11%) had reoperation because of expanding mass. Stable disease was seen in 40% of patients (n = 34), and increase in radiographically detected mass was observed in 41 patients (48.8%). Although the treatment of recurrent GBM is mostly palliative, the fractionated radiosurgery offers a chance for prolonged survival, especially in patients with a smaller tumor volume.

Fractionated stereotactic radiosurgery and concurrent taxol in recurrent glioblastoma multiforme: a preliminary report

PURPOSE

Surgery and systemic chemotherapy offer modest benefit to patients with recurrent glioblastoma multiforme. These tumors are associated with rapid growth and progressive neurological deterioration. Radiosurgery offers a rational alternative treatment, delivering intensive local therapy. A pilot protocol to treat recurrent glioblastoma was developed using fractionated stereotactic radiosurgery with concurrent intravenous (i.v.) Taxol as a radiation sensitizer.

METHODS AND MATERIALS

The treatment outcome was analyzed in 14 patients with recurrent glioblastoma treated with fractionated stereotactic radiosurgery and concurrent Taxol. Median tumor volume was 15.7 cc and patients received a mean radiation dose of 6.2 Gy at 90% isodose line, 4 times weekly. The median dose of Taxol was 120 mg/m2.

RESULTS

The median survival was 14.2 months, 1-year survival was 50%.

CONCLUSIONS

Survival for this small group of patients was similar to or better than historical controls or patients treated with single-fraction radiosurgery alone. This data should stimulate the investigation of both fractionated radiosurgery and the development of radiation sensitizers to further enhance treatment.

Skeletal muscle metastasis in a patient with Wilms tumor and multiple late recurrences

Stage III Wilms tumor was diagnosed in a 9-year-old girl. Four and a half years after the treatment, which consisted of an operation, radiation therapy, and chemotherapy, the patient had a solitary metastasis in the liver, which was successfully treated with chemotherapy and surgical resection. Five years later, right lung metastases were eradicated by chemotherapy, radiation, and surgical resection. Three and a half years later, she had a metastasis in the left calf, for which she underwent surgical resection and received chemotherapy. This patient has several interesting features: (1) multiple recurrences, two in the usual sites of metastasis and one in an extremely rare site, i.e., skeletal muscle; (2) long intervals between recurrences; and (3) unusual histopathologic features, i.e., gradual evolution from a triphasic Wilms tumor at the primary site, to a predominance of differentiated mucinous epithelium in the skeletal muscle metastasis.