Diffuse large B-cell and follicular lymphoma presenting as a slowly growing compressive goiter: A case report and literature review

Abstract

Introduction: Neck ultrasonography with fine-needle aspiration cytology (FNAC) is the diagnostic modality of choice for clinicians who routinely work up a thyroid mass. Distinguishing chronic lymphocytic infiltration from a lymphoproliferative process with FNAC in patients with Hashimoto's thyroiditis presenting with a goiter can be particularly challenging.

Case description: A 58 y.o. female with a history of a goiter showing interval growth and compressive symptoms over 18 months, was treated with a thyroid lobectomy. Surgical pathology demonstrated a thyroid lymphoma (TL) with mixed follicular and diffuse large B cell (DLBCL) components, not initially diagnosed by FNAC. Staging workup showed the involvement of chest lymph nodes only, consistent with Stage IIE disease. She was treated with combination chemotherapy and immunotherapy, followed by involved-field radiotherapy.

Discussion: TL often arises in a background of chronic lymphocytic thyroiditis which can make its histological diagnosis a challenge. The disease is heterogeneous in histological subtype and progression.

Conclusion: While TL usually presents as a rapidly growing neck mass, indolent types can present as a slow growing mass with subsequent transformation. Patients may benefit from avoiding unnecessary diagnostic steps, including surgery, and potential delays in treatment by performing a core needle biopsy when a lymphoproliferative process cannot be excluded if FNAC was initially performed.

Keywords: Case report; Diffuse large B cell lymphoma; Goiter; Thyroid lobectomy; Thyroid lymphoma.

Fig. 1

Gross photographs of the lobectomy specimen showing (a) sequential slices from superior to inferior and (b) a closer view of the tan, fleshy, and nodular appearance of the tumor.

Fig. 2

(a) Photomicrograph demonstrating adjacent lymphocytic thyroiditis (hematoxylin and eosin; magnification 100×). (b) Low-power (hematoxylin and eosin; magnification 200×) and high-power (inset; hematoxylin and eosin; magnification 1000× oil immersion) photomicrographs of FL and (c) low-power (hematoxylin and eosin; magnification 200×) and high-power (inset; hematoxylin and eosin; magnification 1000× oil immersion) photomicrographs of DLBCL.

Fig. 3

(a) Photomicrograph showing FL (arrowhead) and DLBCL (arrow) replacing normal thyroid parenchyma (hematoxylin and eosin; magnification 200×). (b) Ki-67 proliferation index is approximately 20% in the areas involved by FL and 90% in the areas involved by DLBCL (magnification 200×). The neoplastic B-cells are positive for (c) CD20 (magnification 200×) and (d) CD10 (magnification 200×).