Case 96-3
History/Physical Findings:
A 62-year-old white woman presented with stridor due to a neck mass
which was clinically suspicious for multinodular goiter. The patient
was placed on Synthroid, however, the gland continued to enlarge over
the course of three weeks as evidenced by increased stridor and
dysphagia. She reported a 40 pound weight loss over the previous six
months. Additional symptoms included chronic fatigue and occasional
chills. She reported a 36 pack year history of tobacco use.
Thyroid studies performed at the initial consultation included:
total thyroxine 19.0 ug/dL (normal range=4.5-10.9 ug/dL), TSH 0.04
uIU/mL (normal range = 0.4-6.0 uIU/mL) and thyroid hormone uptake 27%
(normal range = 25-35%).
Due to the compression of the trachea a total thyroidectomy was
performed. The gland measured 14 x 12 x 7 cm and weighed 460 grams.
 The entire gland is shown, with asymmetrical
enlargement of the right side.
 The
cut section of the right lobe showed a necrotic center surrounded by
tan fleshy tissue.
 
 
Discussion:
H&E stained sections are shown identifying a diffuse large
lymphocytic infiltrate with rare residual thyroid follicles identified.
A B cell marker, CD 20 (L26), marked the lymphocytes. The T cell
markers, CD 3 and CD 45RO, were negative. Kappa and lambda were
non-contributory. A cytokeratin cocktail highlighted the residual
thyroid follicles but the lymphocytes were negative.
Primary lymphoma of the thyroid consists of approximately 8 percent
of all thyroid malignancies whereas involvement of the thyroid by
systemic lymphoma or leukemia can be found in approximately 10 % of
cases.
Primary thyroid lymphoma is usually seen in patients in their
sixties with a female to male ratio varying from 2:1 to 8:1. The
duration of symptoms is usually short and include hoarseness, dysphagia
and or dyspnea. These symptoms are usually due to extra-thyroid
extension. Most patients are euthyroid.
Upon gross examination, the tumor presents as a solid mass with a
homogenous bulging surface exhibiting the characteristic fish-flesh
appearance. The interface between normal gland and tumor is usually
ill-defined. Necrosis and hemorrhage are unusual findings in lymphomas
of the thyroid.
The majority of primary thyroid lymphomas are non-Hodgkins lymphomas
and are usually large cell lymphomas with a B cell phenotype. The
second most common lymphoma is the immunoblastic type although poorly
differentiated and intermediate types have also been reported.
In approximately 80% of the cases of thyroid lymphoma the residual
uninvolved gland exhibits features of autoimmune thyroiditis
(Hashimotos's or lymphocytic type). It is speculated that the presence
of thyroiditis predisposes the patient to lymphoma as opposed to the
thyroiditis occurring after the lymphoma. However, the percentage of
patients with thyroiditis who develop lymphoma is low.
Diagnosis:
Primary malignant lymphoma of the thyroid
References:
- Shimaoka K, Sokal JE, Pickren JW. Metastatic neoplasms in the
thyroid gland. Cancer 1962; 15:557-65.
- Heimann R, Vannineuse A, DeSloover C, Dor P. Malignant lymphomas
and undifferentiated small cell carcinoma of the thyroid: a
clinicopathological review in light of the Kiel classification for
malignant lymphomas. Histopathology 1978, 2:201-213.
- Rosai J, Carcangiu ML, Delellis RA. Tumors of the Thyroid Gland.
Atlas of Tumor Pathology, Third Series Fascicle 5, pp267-278. Published
by the Armed Forces Institute of Pathology, Washington DC.
Contributors:
David C. Winston, M.D., PhD
Department of Pathology
University of Virginia Health System
Donald J. Innes, Jr., M.D.
Department of Pathology
University of Virginia Health System
Questions should be addressed to dji@virginia.edu
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