Early cytological diagnosis of extranodal stage I, primary thyroid Non-Hodgkin lymphoma in elderly patients. Report of two cases and review of the literature

Abstract

BackgroundPrimary thyroid lymphomas (PTLs) account for 5% of thyroid malignant tumors and often develop in patients with Hashimoto Thyroiditis (HT). Fine-needle cytology (FNC) is widely used in the diagnosis of thyroid nodules, including those arising in HT. Two PTL cases in HT elderly patients are here described and discussed.MethodsFNC was performed in rapidly enlarged thyroid nodules of 2 elderly patients under ultrasound (US) control. FNC was used to prepare conventional cytologic smears, immunocytochemistry (ICC) and flow cytometry (FC) assessment of cell populations.ResultsThe above cases were diagnosed as well differentiated, small B-cell and diffuse large B-cell thyroid lymphomas, respectively, by means of FNC. The histological diagnoses were mucosa-associated non Hodgkin lymphoma (MALT) and diffuse large B-cell lymphoma (DLBCL), confirming FNC diagnoses, and patients were treated accordingly.ConclusionsFNC diagnosis of PTL is reliable and accurate; it may be conveniently used in the clinical practice since it provides indications for appropriate therapeutic procedures or diagnostic surgery, and avoids to treat benign nodules.

Fine Needle Cytology and Flow Cytometry in Hashimoto Thyroiditis and Primary Thyroid Lymphoma

“…The authors assessed the role that FC can play in the FNC diagnosis of HT and TL. Some years ago, we investigated HT and TL by FNC and FC [2,3] and our results were in agreement with theirs. In addition, we would like to draw attention to a specific aspect of their study: clonality was detected in 3 of their 33 HT cases, but in 1 case only a mucosa-associated non-Hodgkin lymphoma was subsequently proven.…”

Ultrasonographic features of aggressive primary thyroid diffuse B-cell lymphoma: A report of two cases

“…When presenting as a diffuse heterogeneous hypoechoic parenchyma, the ultrasonographic imaging features of PTL are very similar to those of HT (11). By contrast, cervical lymphadenopathies are normally present in the majority of patients with PTL, whereas calcification is never detected in HT and seldom detected in PTL, according to previous studies (12). The patient of case 2 had no history of HT, numerous enlarged lymph nodes were detected in his neck and multiple calcified spots were detected in his enlarged thyroid, which indicated malignancy.…”

“…The patient of case 2 had no history of HT, numerous enlarged lymph nodes were detected in his neck and multiple calcified spots were detected in his enlarged thyroid, which indicated malignancy. When presenting as a mass, PTL normally displays homogenous echogenicity, PAE, and lack of calcification, necrosis and cystic degeneration (13), while the surrounding structures are rarely invaded by PTL (12). Notably, PAE is the most common ultrasonographic feature of PTL, and it may also be detected in cystic lesions and solid benign tumors, but rarely detected in malignant masses (14).…”

Utilility of flow cytometry as ancillary study to improve the cytologic diagnosis of thyroid lymphomas

“…The distinction between DLBCL and anaplastic thyroid carcinoma can also be difficult by FNAC if cytologic features of B cell resembles pleomorphic feature of anaplastic carcinoma cells (30,31). Ancillary studies such as FC and ICC are necessary in these cases to perform a differential diagnosis.…”