Plasma Cell Granuloma of the Thyroid and Hashimoto Thyroiditis

Plasma Cell Granuloma of the Thyroid: Review of an Uncommon Entity

Plasma cell granuloma (PCG) is characterized by proliferation of polyclonal plasma cells with associated fibrosis and is often considered part of the heterogeneous group of inflammatory myofibroblastic tumors (IMTs). The thyroid is rarely affected by PCG. A patient having PCG associated with Hashimoto thyroiditis (HT) prompted our literature search that revealed 18 cases of PCG, 55% (n = 10) of which occurred together with HT. The etiopathogenesis of PCG is unknown and there is no specific treatment except surgical excision for compressive symptoms. This entity has an excellent prognosis with no evidence of recurrence or metastasis. Lesions of the thyroid with infiltrating plasma cells include HT, fibrous variant of HT, plasmacytoma, plasma cell myeloma, Riedel thyroiditis, IgG4 (immunoglobulin G4)-related disease, IMT, and PCG. Inflammatory myofibroblastic tumor has ALK gene rearrangements and is considered a neoplasm as opposed to PCG, which is a reactive polyclonal plasma cell proliferation. We believe IMT and PCG are distinct entities and consensus definitions are required for avoiding confusion in the literature.

A case report of recurrent thyroid inflammatory myofibroblastic tumor and its metastasis in soft tissue

RATIONALE

Inflammatory myofibroblastic tumor (IMT) is a neoplasm of low malignant potential. The most frequent site of IMT is in the lung, whereas recurrent and metastasis of thyroid IMT has been seldom reported.

PATIENT CONCERNS

A 57-year-old male presented with a 3-year history of painless thyroid mass. The physical examination revealed a diffusely enlarged thyroid which was firm. The thyroid function and antibodies were normal. Thyroid ultrasound revealed a hypoechoic mass in the left lobe and heterogeneous echo in the right lobe. Neck computed tomography showed a diffused enlargement of thyroid with the homogeneously low intensity and the moderate enhancement.

DIAGNOSES

A diagnosis of thyroid IMT was made according the postoperative histological and immunohistochemical analysis.

INTERVENTIONS

The patient underwent subtotal thyroidectomy. Seventeen months after the surgery, the patients presented with a firm nodule of right adductor magnus and a relapsing mass of thyroid. Needle core biopsy of the thyroid mass suggested the relapsing of thyroid IMT. The mass excision of the right adductor magnus was performed and an IMT was confirmed by histopathology. The patient underwent thyroid radiation therapy and steroid therapy.

OUTCOMES

The size of the tumor was smaller than the preradiation size and the patient is now under follow-up.

LESSONS

This is the seldom reported patient with recurrent thyroid IMT with metastasis. IMT of the thyroid is an unusual but distinct disease entity. The clinical and radiological features are not specific and its diagnosis is based on the histological features. Although tumor resection and radiation seem to be effective, no standard treatment for such disease has been established.

Inflammatory Myofibroblastic Tumour of Thyroid with its Prominent Spindle Cell Pattern: A Rare Case Report

Inflammatory myofibroblastic tumour of thyroid is very rare. Only 18 cases reported so far. Here we report a case of Inflammatory myofibroblastic tumour with its prominent spindle cell (fibrohistiocytic) pattern in a 61-year-old male patient. The dominant histological pattern in our case was myofibroblastic in contrast to prominent lymphoplasmocytic pattern in other previously reported cases. The tumour was strongly positive for vimentin, Anaplastic lymphoma kinase and showed focal positivity for Smooth Muscle Actin. The patient was treated with total thyroidectomy and he is comfortable after surgery.

Plasma Cell Granuloma of the Thyroid Gland

This study reports a case of plasma cell granuloma of the thyroid gland in a 47-year-old woman, presenting with a right subhyoid mass and a previous diagnosis of Hashimoto thyroiditis dating back to 1988, which was made on a subtotal thyroidectomy. Plasma cell granuloma preferentially involves the lung, with only 18 cases of thyroid gland involvement having been reported to date in the English literature. Thyroid plasma cell granuloma preferentially affects women and classically shows a prominent plasma cell infiltrate embedded in a variable degree of fibrous stroma: only 2 of the reported cases exhibited the morphologic features of inflammatory myofibroblastic tumor. These morphologic features may raise problems in the differential diagnosis with other plasma cell–rich disorders, including infectious diseases and auto(dys)immune conditions, including the recently described “IgG4-related sclerosing disease.” In view of these considerations, a contemporary diagnostic approach to thyroid plasma cell granuloma is therefore discussed here.

Plasma cell granuloma of the thyroid: a conservative approach to a rare condition and review of the literature

Introduction. We present a case of an 89-year-old female who attended our surgical endocrine clinic with a 3-month history of a left-sided neck lump. There was no past medical history of thyroid disease. Methods. Following examination and further investigation, including core biopsy, a diagnosis of plasma cell granuloma of the thyroid was made. Biochemical testing of thyroid function and Thyroid Peroxidase Antibody was in-keeping with an associated Hashimoto's thyroiditis. Results. The patient was treated conservatively with thyroxine and regularly seen in clinic. TSH levels improved and the lump showed signs of regression. Conclusion. Plasma cell granuloma of the thyroid is rare with only 16 previously reported cases. We present a new approach to management without the use of surgery or steroids. The literature is reviewed comparing clinico-pathological features and management of other reported cases.

Inflammatory pseudotumor of the thyroid gland showing prominent fibrohistiocytic proliferation. A case report

Inflammatory pseudotumor of the thyroid gland (IPT) appears to be exceedingly rare. Histologically, 14 previously reported cases demonstrated plasma cell granuloma variant. We report here an IPT showing a predominantly fibrohistiocytic proliferation that occurred in a 75-year-old Japanese woman. Histologically, the lesion was characterized by haphazardly arranged spindle cells, histiocytes having foamy cytoplasm containing intracytoplasmic brown pigments, and small lymphocytes. Immunohistochemical study demonstrated that the spindle cells were vimentin+, desmin-, muscle-specific actin+, cytokeratin-, endomysial antibody-, anaplastic lymphoma kinase-, CD34-- CD68+/-, CD99-, cyclin D1-, bcl-2-, and antifollicular dendritic cell antibody-. IPT showing a predominant fibrohistiocytic proliferation should be differentiated from various nonneoplastic or neoplastic disorders showing spindle cell proliferation and/or exuberant fibrosis. They include Riedel's thyroiditis, fibrous variant of chronic thyroiditis, papillary carcinoma with exuberant nodular fasciitis-like stroma, paucicellular variant of anaplastic thyroid carcinoma, and solitary fibrous tumor.

Plasma cell granuloma of the thyroid gland mimicking carcinoma: A case report and review of the literature

Plasma cell granulomas (PCG) are rare tumor-like lesions consisting of sheets of polyclonal plasma cells admixed with numerous lymphocytes and other inflammatory cells surrounded by fibrous stroma. They usually appear in the lung, but involvement of diverse extrapulmonal sites has been described. PCGs occurring in the thyroid are very uncommon. Since 1981, only 11 cases have been described in the English literature. Here, we present the case of a 50-year-old Arabic man who noticed an enlargement of his thyroid gland during the previous 2 years, and he developed swallowing disturbances and a feeling of narrowness in the neck. A nearly total resection of the thyroid gland was made because of clinical suspicion of carcinoma. On histologic examination, PCG of the thyroid associated with Hashimoto's thyroiditis (HT) was diagnosed. This is the first case in which molecular pathological analyses for EBV and HHV8 DNA were made. As these were negative, distinct etiological features were suggested.

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

A 40-year-old woman presented with a rapidly enlarging palpable thyroid mass. The patient underwent a total thyroidectomy. The tumor fulfilled the criteria of primary solitary extramedullary plasmacytoma (SEP), including cellular expression of the CD138 and lambda light chain antibodies. Solitary extramedullary plasmacytoma of the thyroid occurs most commonly in patients with Hashimoto thyroiditis and must be distinguished from involvement of thyroid in multiple myeloma, inflammatory pseudotumor plasma cell variant, mucosa-associated lymphoid tissue lymphoma, and medullary carcinoma. The distinction is determined on the basis of histologic findings, immunohistochemical analysis, and other laboratory tests. Currently, no standard treatment exists for this entity. In this report, we discuss the differential diagnosis of SEP of the thyroid and the clinical features observed in this case.