Clinical features and differential diagnoses of solitary extramedullary plasmacytoma of the thyroid: a case report

Solitary Extramedullary Plasmacytoma of the Thyroid Gland in a Patient With Subclinical Hyperthyroidism

Objective

Solitary extramedullary plasmacytoma (SEP) of the thyroid is rare, and its clinical and pathologic features are not entirely understood. Generally, patients with SEP of the thyroid also present with Hashimoto thyroiditis. We report, for the first time, a case of SEP of the thyroid in a patient with subclinical hyperthyroidism.

Methods

A 46-year-old woman presented to the emergency department with symptoms consistent with a panic attack. Following a physical examination, neck ultrasonography, and laboratory tests, we determined that the patient was hyperthyroid and possessed a toxic multinodular goiter. The patient elected to undergo a total thyroidectomy to treat the subclinical hyperthyroidism and to remove the nodules.

Results

SEP diagnosis requires consideration of the systemic spread of multiple myeloma and a combination of immunohistochemical examination, imaging, and other laboratory tests. Upon further examination, we confirmed SEP through the following criteria: the absence of kidney failure or hypercalcemia, a biopsy demonstrating plasma cell histology, a lack of bone or tissue involvement, and low serum myeloma protein concentration. The immunophenotype of the tumor cells further confirmed SEP diagnosis, with positivity for CD138, CD79a, and lambda light chain antibodies and no reactivity toward cyclin D1.

Conclusion

This case fulfilled the criteria for SEP, and we were able to rule out multiple myeloma. Currently, no standard treatment exists for SEP. Yet, the prognosis remains encouraging. Going forward, SEP of the thyroid should be considered in the differential diagnosis of a patient with subclinical hyperthyroidism and a toxic multinodular goiter.

A Case Report of Thyroid Plasmacytoma and Literature Update

Plasmacytomas of the thyroid gland are rare, whether or not they arise as solitary (primary) lesions or secondary to systemic multiple myeloma. Here, we present the case of a 71-year-old female presenting with goiter and Hashimoto’s thyroiditis, in whom the subsequent histopathological diagnosis of plasmacytoma was a surprise. In presenting this case, we summarize the last 25 years of literature on thyroid plasmacytoma and review the salient clinicopathological characteristics, differential diagnoses, management, and outcomes of this rare condition.

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.

Renal plasmacytoma: Report of a rare case and review of the literature

Renal plasmacytoma is extremely rare, presenting diagnostic challenges due to its unusual location and non-specific or absent symptoms. To the best of our knowledge, only 24 cases of renal plasmacytoma have been reported in the literature. The present study reports a case of primary renal plasmacytoma in a 46-year-old female patient. Computed tomography (CT) revealed that the mass was located in the lower pole of the left kidney and metastasis was detected in an enlarged para-aortic lymph node. Following careful preparation, a partial nephrectomy was performed and the retroperitoneal lymph node was resected. A pathological examination revealed a renal parenchyma with lymph node involvement; this was confirmed by immunohistochemistry and nested polymerase chain reaction (PCR). Consequently, a diagnosis of a renal extramedullary plasmacytoma (EMP) was proposed. Following this unexpected diagnosis, various examinations were performed, but there was no evidence of systemic plasma cell disease. The patient refused further therapy, including external beam radiotherapy and chemotherapy. Abdominal CT was performed three months post-surgery and did not reveal any relapse. The patient remains disease-free at nine months post-surgery. The current study also presents a review of the literature. Although the general prognosis and outcome of EMP is good, a follow-up examination is recommended due to the possibility of relapse or progression to plasma cell neoplasm (PCN).

Gamma heavy chain disease in a patient with underlying lymphoplasmacytic lymphoma of the thyroid. Report of a case and comparison with other reported cases with thyroid involvement

BACKGROUND

Gamma heavy chain disease with underlying thyroid pathology is rare. There are 5 reported cases in the English literature, including the present case of an elderly female with γ heavy chain disease with underlying lymphoplasmacytic lymphoma of the thyroid who initially presented with long-standing goiter and chronic thyroiditis.

METHODS

The protein studies and histopathologic findings in her thyroid are described. Her case is compared with reported cases of γ heavy chain disease with thyroid involvement.

RESULTS

Initial impression on most cases was chronic thyroiditis; however pathology showed 3 cases with plasmacytoma and 2 with lymphoplasmacytic infiltrate. All were diagnosed and followed up using serum and urine electrophoresis.

CONCLUSION

Gamma heavy chain disease has a protean manifestation; however there appears to be a more uniform pattern of the disease when it is associated with the thyroid. The inclusion of protein studies in cases diagnosed with chronic thyroiditis by FNA may aid in establishing γ heavy chain disease with underlying thyroid involvement. In this case serum and urine electrophoresis, and immunofixation studies which are simple and affordable tests facilitated the hematologic workup and follow up.

Solitary extramedullary plasmacytoma of the thyroid gland

Solitary extramedullary plasmacytoma of the thyroid gland is an uncommon condition. Up to date, its clinical pathological features are not fully understood. We present a case of an extramedullary nonmucosal plasmacytoma of the thyroid gland which is the first case with regional metastatic lymph nodes. This condition requires a scrupulous survey to rule out a metastatic multiple myeloma. Although localized forms management is still controversial, authors require combined approach for regional metastatic forms. The prognosis is favorable compared to solitary bone plasmacytomas or multiple myeloma.