Cytologic findings and differential diagnoses of primary thyroid MALT lymphoma with striking plasma cell differentiation and amyloid deposition

Amyloid goiter - A rare case report and literature review

INTRODUCTION

Amyloid goiter is a rare presentation of thyroid swelling, which occurs with either primary or secondary amyloidosis. This condition must be differentiated from other types of goiters or malignancies. Even though the thyroid is extensively involved by amyloid, patients are usually euthyroid, but many different presentations and overlaps have been reported. Currently the treatment is surgical resection of the thyroid gland.

CASE PRESENTATION

We report a case of a 53-year-old previously healthy male who presented with a 2 year history of a progressively enlarging painless neck swelling. The patient was euthyroid and denied any associated symptoms. The patient subsequently underwent an uneventful total thyroidectomy along with an unremarkable follow up and was diagnosed with primary amyloidosis involving only the thyroid gland confirmed by histopathology.

DISCUSSION AND CONCLUSION

Amyloid goiter is a rare entity; a high index of suspicion is required in patients with an enlarging thyroid gland and a concomitant history of chronic inflammatory processes or plasma cell dyscrasia. FNA biopsy should be performed to exclude the top differential of primary thyroid malignancy. Thyroidectomy is necessary for definitive diagnosis and symptom relief. Every effort should be made to delineate the extent of the disease, and in those previously healthy plasma cell dyscrasia should be excluded.

Primary thymic mucosa-associated lymphoid tissue lymphoma complicated with renal amyloidosis: A first case report

INTRODUCTION

Primary mucosa-associated lymphoid tissue (MALT) lymphomas originating in thymus is rare. And, there have been few reports of patients with MALT coexisting with amyloidosis. As far as we know, this was the first case report on MALT lymphoma associated with renal amyloidosis.

PATIENT CONCERNS

A 57-year-old man presented with nephrotic syndrome. Further workup revealed IgM-Lambda type monoclonal gammopathy. Bone marrow biopsy showed 8% clonal plasma cells. Renal biopsy confirmed the diagnosis of Lambda light chain AL amyloidosis. positron emission tomography/computed tomography showed thymic lesions which upon biopsy were diagnosed as MALT lymphoma of the thymus.

DIAGNOSIS

Primary thymic MALT lymphoma complicated with renal amyloidosis.

INTERVENTIONS

The patient underwent surgical resection of the thymus mass and 2 courses of chemotherapy.

OUTCOMES

Follow-up data showed that the patient survived 18 months after surgical excision and chemotherapy.

CONCLUSION

The case highlights the importance of screening for malignancy in patients with renal amyloidosis.

AMYLOID GOITER AS THE FIRST RECOGNIZABLE MANIFESTATION OF IMMUNOGLOBULIN LIGHT CHAIN AMYLOIDOSIS

Objective

Clinically apparent thyroid enlargement due to massive amounts of amyloid deposition, known as amyloid goiter, is rare. Endocrinologists should become familiar with this manifestation of systemic amyloidosis, which may be diagnosed by Congo red staining of the specimen obtained by fine-needle aspiration.

Methods

We describe a 70-year-old man who presented with a slowly enlarging goiter. It was asymptomatic, predominantly left-sided, nontoxic, and multinodular with atypia of undetermined significance (Bethesda System category III) by cytology. The goiter tested negative using the ThyraMIR miRNA Gene Expression Classifier kit (eviCore Healthcare, Bluffton, SC).

Results

Left thyroid lobectomy produced a 220-g specimen with nodular hyperplasia and prominent amyloid deposition confirmed by Congo red staining. Liquid chromatography tandem mass spectrometry detected a peptide profile consistent with light chain amyloid deposition of the lambda type, formerly called primary amyloidosis. In retrospect, he had been diagnosed with restrictive cardiomyopathy, cardiac conduction system disease, coronary artery disease, non-nephrotic range proteinuria, and chronic kidney disease, which had been attributed to his longstanding type 2 diabetes mellitus. Extensive workup subsequently demonstrated cardiac amyloidosis and monoclonal gammopathy of unknown significance, consistent with light chain amyloidosis.

Conclusion

Amyloid goiter should be included in the differential diagnosis of enlarging goiters with Bethesda System category III cytology in patients with monoclonal gammopathy of uncertain significance, clinical manifestations of systemic amyloidosis, or known diagnosis of monoclonal cell dyscrasia.

Cytological findings for the diagnosis of primary thyroid mucosa-associated lymphoid tissue lymphoma by fine needle aspiration

OBJECTIVE

We examined cytological findings for the diagnosis of primary thyroid mucosa-associated lymphoid tissue (MALT) lymphoma by fine needle aspiration.

STUDY DESIGN

During the study period of 4 years, a total of 101 cases including 51 MALT lymphomas, 20 Hashimoto's thyroiditis (HT), and 30 diffuse large-cell B-cell lymphomas were cytologically examined. MALT lymphomas were divided into 44 common MALT and 7 MALT lymphomas with extreme plasmacytic differentiation (MALT-EPCD).

RESULTS

(1) Small- to medium-sized cells displaying irregularly shaped nuclei with prominent nucleoli (ISN-PN) were neoplastic cells. (2) In the case of a frequency of plasma cells (PC) below 15%, the accuracy rate for distinguishing common MALT from HT was 97% for ISN-PN cell frequencies above 20% in combination with the presence of lymphoepithelial lesion clusters (LELC) and mountain range-like clusters (MRLC). The frequency of large-sized cells was below 15% in common MALT. (3) In the case of a frequency of PC above 15%, cases with a sum of PC and ISN-PN cells above 30% were MALT-EPCD. (4) MRLC were cell clusters derived from regions of follicular colonization, and LELC were cell clusters from lymphoepithelial lesions of MALT lymphomas.

CONCLUSION

Useful cytological criteria for the diagnosis of thyroid primary MALT lymphoma, such as neoplastic cells and cell clusters, were defined.