Anaplastic giant and spindle-cell carcinoma of the thyroid: a different therapeutic approach

Diagnosis and Management of Anaplastic Thyroid Cancer

Anaplastic thyroid cancer (ATC) is a devastating and usually incurable diagnosis. Clinical and pathologic diagnosis is best assessed at a tertiary center with concentrated ATC expertise. Expeditious multidisciplinary management is recommended for optimal patient outcomes. Based on multiinstitutional and population-based studies, multimodal therapy that includes chemoradiotherapy with surgery (when feasible) is the preferred initial treatment because it is associated with incrementally improved overall survival. In ATC that carries a BRAF V600E somatic mutation, combination therapy with BRAF and MEK inhibitors has shown promise but needs further study. Immunotherapeutic agents in neoadjuvant and metastatic settings are being investigated.

Aggressive variants of follicular cell derived thyroid carcinoma; the so called 'real thyroid carcinomas'

The pathological diagnoses and classification schemes for thyroid carcinoma have changed over the past 20 years and continue to do so. New entities have been described and molecular analyses have suggested better characterisation and grouping of certain tumours. Because some of the lesions have been named differently by different authors, clinicians and patients may be confused as to what a specific patient's lesion represents. In this review, we discuss the thyroid tumours of follicular origin which are clinically unusual but important to recognise as their behaviour may be aggressive, they may not respond to radioiodine treatment and they may cause significant mortality. This paper describes these important but rare lesions, their pathological features, important clinicopathological correlations, molecular correlates and prognostic implications.

[Anaplastic cancers of the thyroid. Is healing possible?]

OBJECTIVE

Thyroid anaplastic carcinoma is associated with a very poor prognosis. The goal of this study was to determine whether an aggressive treatment is worthwhile.

PATIENTS AND METHODS

Of 22 thyroid anaplastic carcinomas confirmed with immunohistochemistry, 17 were judged eligible for surgery. Total thyroidectomy was planned in all patients. Frozen section of the lower lateral lymph nodes was routinely performed and in case of involvement (n = 9), a modified radical neck dissection was carried out. Fractionated radiotherapy was started within 5 weeks following surgery: 6,000 cGy was delivered on the thyroid area and all involved areas while 4,500 cGy was delivered on the lymph nodes of the neck and of the superior mediastinum when non involved.

RESULTS

The three patients without distant metastasis, with thyroid removal considered as complete, were still free of disease 10, 12 and 13 years later. One of these patients had been initially considered inoperable and was operated later when a combination of radiotherapy and chemotherapy obtained a decrease of the tumor. All other patients, 13 with incomplete removal and one with pulmonary metastasis died from their cancer; the median of the survival was 7 months.

CONCLUSION

When anaplastic carcinoma is suspected on clinical appearance, the diagnosis should be rapidly confirmed with percutaneous biopsy and immunohistochemistry. If a lymphoma is found, surgery is not indicated. Our results demonstrate that except for widely infiltrating tumors or distant metastasis, a complete removal of the tumor should be attempted as soon as possible. Surgery should be followed with hyperfractionated radiotherapy. Multimodal therapy may result in long-term survival. A patient free of disease at 5 years may be considered as definitively cured.

Anaplastic thyroid carcinoma: a therapeutic challenge

Anaplastic thyroid carcinoma is an extremely aggressive solid tumor that resists most therapeutic efforts and is almost always fatal. It typically arises as a terminal dedifferentiation of unrecognized long-standing differentiated thyroid carcinoma. Current chemotherapeutic agents are not capable of consistent beneficial therapeutic responses, although rare patients may gain additional months of survival. Aggressive local tumor control with surgery and external beam radiotherapy may provide palliation and delay eventual death from distant metastatic disease. This disease challenges clinicians and researchers to develop new systemic therapies as well as to aggressively treat differentiated thyroid cancers before they become anaplastic tumors.

Anaplastic thyroid carcinoma: behavior, biology, and therapeutic approaches

Anaplastic thyroid carcinoma (ATC), although exceedingly rare, is the most aggressive solid tumor known. Early studies on the effects of different therapies may be biased by the inclusion of responsive "small cell" ATC patients, which are now known to be mostly lymphoma patients. Local control of disease with surgery and/or external beam radiotherapy (XRT) is of fundamental importance to enhance survival. Ultimately, nearly all ATC patients die from their disease, which is widely metastatic. Development of effective systemic chemotherapy agents would provide the best chance for long-term survival of patients. Early preliminary data suggest that paclitaxel may be helpful, although no agent has yet been identified to result in dramatic improvements in survival. Select patients may benefit from aggressive multimodal therapy, although it is important to provide appropriate palliative care when desired.

Anaplastic thyroid carcinoma: cytomorphology and clinical implications of fine-needle aspiration

Four cases of anaplastic carcinoma of the thyroid were diagnosed in 1,519 thyroid aspirates. All patients had unilateral or diffuse nodular enlargement of the thyroid. One patient had a concurrent grade 1 mucinous carcinoma of the ovary. Cytologically, the neoplasms were characterized by pleomorphic giant or spindle cells with multilobulated, single or multiple nuclei. The chromatin pattern was clumped with prominent parachromatin clearing, and there were multiple prominent nucleoli. Associated papillary and follicular structures were recognized in two aspirates. All cytologic preparations were considered diagnostic of malignancy. Examination of histologic material revealed the same elements identified cytologically on the aspiration smears. Three patients died shortly after diagnosis due to massive local tumor growth in the neck. One patient, who received radiation therapy, had a prolonged survival of 30 mo, but died then of local neck recurrence. The cytologic features of anaplastic carcinoma parallel their histologic appearance. Histologic confirmation of cytologically diagnosed anaplastic carcinoma is not necessary.

Thyroid carcinoma

The issue of appropriate management for thyroid neoplasms remains unsettled. Confusion concerning histology and classification, controversy as to appropriate therapy, the relative indolence of most differentiated thyroid tumors, and various levels of surgical skill have contributed to the prejudice of various approaches to the management of such neoplasms. It appears unlikely that the controversy will be resolved in the immediate future. If total thyroidectomy can be performed by a skilled surgeon with minimal complications, this approach seems theoretically justifiable for the management of most differentiated tumors, facilitating follow-up postoperatively. Conclusive evidence for improved survival with this rationale is insufficient.

Anaplastic carcinoma of the thyroid: a clinicopathologic study of 82 cases

Anaplastic carcinoma of the thyroid accounts for about 10% to 15% of all thyroid carcinomas in the United States. Its lethality is evidenced by a 5-year survival rate of 3.6% and a median survival of 4 months. Rapid growth of a thyroid mass, frequently in a preexisting goiter, is the most common manifestation; the diagnosis should be considered and expeditiously pursued in all patients who present with this finding. Relatively favorable prognostic features seem to be unilateral tumors, a tumor diameter of less than 5 cm, no invasion of adjacent tissue, and absence of nodal involvement. For resectable lesions, thyroid lobectomy with wide margins of adjacent soft tissue on the side of the tumor seems to constitute a safe, appropriately aggressive surgical approach. Total thyroidectomy and radical neck dissection results in an increased complication rate and has no advantage over a more conservative approach. Radiotherapy, chemotherapy, immunotherapy, and combination radiotherapy and chemotherapy need further evaluation.