Fine needle aspiration cytology of primary lymphoma of the thyroid: a report of 17 cases

Fine-needle aspiration diagnosis of secondary malignant tumors of the thyroid gland: A single-institution experience of 17 cases

BACKGROUND

Fine-needle aspiration (FNA) is the most commonly used preoperative pathological diagnostic tool for thyroid tumors. Secondary malignant tumors of the thyroid gland account for less than 3% of all thyroid malignancies. The aim of this study was to investigate the types and cytopathological features of secondary thyroid tumors, evaluate diagnostic pitfalls in FNA.

METHODS

Cases of secondary thyroid tumors diagnosed in the Department of Pathology of Shaanxi Provincial People's Hospital were collected, and their clinical data, cytologic features, immunohistochemical results, and histopathological diagnoses were summarized.

RESULTS

The study included 17 cases (8 males and 9 females) with a mean age of 60.4 ± 9.4 years (range, 45-83 years). Six cases had a known history of primary malignancy prior to FNA aspiration diagnosis. The most common organs of origin were the lungs (5 cases, 3 adenocarcinoma, and 2 small-cell carcinoma) and esophagus (5 cases, 3 squamous-cell carcinoma, 1 adenocarcinoma, and 1 small-cell carcinoma). The next most common was squamous-cell carcinoma of the larynx (3 cases), and gastric tumor (2 cases), including 1 lymphoma and 1 adenocarcinoma. Cell blocks and immunohistochemistry were performed in 12 of these cases. Comparison of the impact of positive history and IHC availability on the accuracy of pathologic diagnosis showed that both were statistically significant.

CONCLUSION

FNA is an effective means of diagnosing secondary malignancies of the thyroid, in which knowledge of the patient's history of malignancy is essential, and the use of cell blocks and immunohistochemistry helps to clarify the pathological diagnosis.

Two lymphoma histotypes and papillary thyroid carcinoma coexisting on Hashimoto ground: a case report and review of the literature

BACKGROUND

Papillary carcinoma is the most frequent type of thyroid carcinoma, while primary thyroid lymphoma is uncommon disease. The coexistence of these entities has already been described, and the common risk factor is considered Hashimoto thyroiditis. The two most frequent histotypes of primary thyroid lymphoma are diffuse large B-cell and mucosa-associated lymphoid tissue lymphoma, but the coexistence of both with papillary carcinoma is rarely reported.

METHODS

We present a case of a previously healthy 57-years old male with rapidly growing lump on the right side of the neck. Ultrasonography revealed nodules in both thyroid lobes. Fine needle aspiration cytology and pertechnetate scintigraphy were performed. Due to the Bethesda T-5 in the "cold" nodule of the right lobe, surgery with histopathological and immunohistochemistry analysis was indicated.

RESULTS

Histopathological and immunohistochemistry methods confirmed concomitant malignancies in the thyroid gland: diffuse large B-cell lymphoma and papillary carcinoma in the right, and mucosa-associated lymphoid tissue lymphoma in the left lobe with Hashimoto thyroiditis in the remaining tissue. Patient underwent therapy procedures and was without signs of local recurrence or metastatic spread on subsequent follow-up.

CONCLUSIONS

Sudden appearance of the neck mass in patients with Hashimoto thyroiditis should raise suspicion on primary thyroid lymphoma and be promptly taken in the diagnostic workup, including fine needle aspiration cytology. Pathology with immunohistochemistry is crucial for further clinical decision making. Since the standardized protocol in management of these complex patients is missing, personal approach and close collaboration between cytologist, pathologist, surgeon, haematologist and nuclear medicine specialist is essential.

The risk of malignancy in the atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) category subgroups: a Thai institute experience

INTRODUCTION

This study investigated the rate of reporting and the risk of malignancy (ROM) for atypia of undetermined significance (AUS) subgroups in a Thai population. AUS, which is category III of the Bethesda System for Reporting Thyroid Cytopathology, is a problematic diagnosis for thyroid nodule management because the risks of malignancy are diverse.

MATERIALS AND METHODS

Patients who underwent thyroid fine needle aspirations between January 2015 and December 2019 were included in this retrospective study. Gender, age, and nodule features were described, and all slides were re-evaluated and categorized into 2 subgroups: AUS-Nuclear (including cytology atypia and cytologic and architectural atypia) and AUS-Other (including architectural atypia, oncocytic atypia, and atypia not otherwise specified). The lower and upper limits of ROM were calculated for each subgroup.

RESULTS

Of total, 258 out of 2995 fine needle aspirations (8.6%) were diagnosed as AUS. The patients were predominantly female (88.9%), with a mean age of 54.1 years. The average nodule size was 2.5 cm. Of the 258 AUS patients, 81 (38.9%) had histological correlations. The ROM for the AUS category was 9.1% to 23.5%. The ROM of the AUS-Nuclear and AUS-Other were 11.1% to 27.3% and 2.2% to 6.7%, respectively. Features of pseudonuclear inclusions had the highest ROM (33.3%-42.9%), followed by pale chromatin (28.57%-47.06%).

CONCLUSIONS

Less than ten percent of our interpretations were AUS, which is acceptable in our practice. Cytological atypia harbored the highest ROM. Studies of associations between cytology and histology may aid in improving diagnostic criteria for this population.

Primary Thyroid Lymphoma: How Molecular Biology and Ancillary Techniques Can Help the Cytopathologist Overcome This Diagnostic Challenge

Primary thyroid lymphoma (PTL) occurs rarely, its diagnosis is a challenge, and the prognosis of these patients depends on the time of diagnosis. Even though fine-needle aspiration cytology (FNAC) is recognized as the most accurate tool for detecting thyroid malignancies, its sensitivity for PTL is poor. Both clinical and ultrasound presentation of PTL can be atypical, and laboratory tests fail to furnish relevant data. Consequently, the reliability of a cytopathologist facing PTL can be poor, even when he is aware of its clinical information. In addition, the cases described in the literature are extremely rare and fragmentary, and consequently, the molecular data currently available for this neoplasm are practically negligible. Here, we present a case report in order to discuss the intrinsic limitations in achieving a final diagnosis of PTL and how using molecular diagnostics to identify potential mutational models can improve the evaluation of this neoplasm.

Diagnosis and treatment of primary thyroid lymphoma from a surgical perspective: a multi-institutional study

PURPOSE

Surgery of primary thyroid lymphoma (PTL) has been mostly limited to diagnostic work-up. This study aimed to further study its potential role.

METHODS

This was a retrospective study from a multi-institutional registry of PTL patients. Clinical, diagnostic work-up (fine needle aspiration, FNA; core needle biopsy, CoreNB), contribution of surgery (open surgical biopsy, OpenSB; thyroidectomy), histology subtype, and outcome data were evaluated.

RESULTS

Some 54 patients were studied. Diagnostic work-up included FNA in 47 patients, CoreNB in 11, and OpenSB in 21. CoreNB yielded the best sensitivity (90.9%). Thyroidectomy was performed in 14 patients with other diagnosis (incidental PTL), in 4 for diagnosis and in 4 for elective treatment of PTL. Incidental PTL was associated with not performed FNA nor CoreNB (OR 52.5; P = 0.008), mucosa-associated lymphoid tissue (MALT) subtype (OR 24.3; P = 0.012), and Hashimoto's thyroiditis (OR 11.1; P = 0.032). Lymphoma-related death (10 cases) mostly occurred within the first year after diagnosis and was associated with diffuse large B-cell (DLBC) subtype (OR 10.3; P = 0.018) and older patients (OR 1.08 for every 1-year increase; P = 0.010). There was a trend towards lower mortality rate in patients receiving thyroidectomy (2/22 versus 8/32, P = 0.172).

CONCLUSION

Incidental PTL accounts for most of thyroid surgery cases and are associated with incomplete diagnostic work-up, Hashimoto's thyroiditis and MALT subtype. CoreNB appears to be the best tool for diagnosis. Most of PTL deaths occurred during the first year after diagnosis and mostly related to systemic treatment. Age and DLBC subtype are poor prognostic factors.

Primary thyroid lymphoma: A single-center experience

BACKGROUND

Primary thyroid lymphoma (PTL) is a very rare entity accounting for 5% of all thyroid malignancies and less than 2% of lymphomas. PTLs are classified as non-Hodgkin's B-cell lymphomas in the majority of cases, although Hodgkin's lymphoma of the thyroid has also been identified. This study aimed to identify the clinical, biochemical, and pathological features of primary thyroid lymphomas.

METHODS

From January 2008 to December 2020, data from patients diagnosed with PTL treated at the Gangnam Severance Hospital, including clinical, biochemical, and pathological features of thyroid lymphomas, were assessed.

RESULTS

Of 10 patients, nine women and one man, with a median age of 62 (range, 44-82) years were included. Fine needle aspiration biopsy was performed in nine patients and surgical resection was performed in one patient without biopsy. Excisional and surgical biopsies were performed in all patients, including five who underwent excisional biopsy and five who underwent thyroidectomy. Histological analyses revealed that all 10 lymphomas were non-Hodgkin B-cell lymphoma; six patients had diffuse large B-cell lymphoma, three had mucosa-associated lymphoid tissue lymphoma, and one had Burkitt lymphoma. Four patients received chemotherapy, two were treated with chemoradiation therapy, one received radiation therapy only, one did not require more treatment after surgery, one refused treatment, and one was transferred to another hospital.

CONCLUSIONS

Although PTLs are scarce, clinicians should be aware of this rare entity and evaluate and treat PTLs on an individual basis.

A Dramatic Response of a Thyroid Lymphoma to R-CHOP Chemotherapy Reversing Mechanical Airway Obstruction and Respiratory Failure

Primary thyroid lymphoma is an extremely rare thyroid malignancy that usually occurs in patients with preexisting Hashimoto thyroiditis and commonly presents in older women. The most common type is non-Hodgkin's lymphoma of B-cell origin, particularly diffuse large B-cell lymphoma (DLBCL), which is primarily treated with chemotherapy and radiotherapy. We reported an 83-year-old woman with a past medical history of hypothyroidism who suffered dysphagia and dyspnea secondary to a large thyroid mass. Her CT neck scan showed an enlarged thyroid mass with pathological cervical lymphadenopathy and marked tracheal narrowing. The ultrasound-guided biopsy confirmed the diagnosis of DLBCL of the thyroid. A few days later, she experienced respiratory distress and failure that required endotracheal intubation and mechanical ventilation. She was not considered for tracheostomy or surgical interventions, and after discussion with her family, the decision was made to start R-CHOP therapy (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) which resulted in a marked reduction of the thyroid size and reversal of the mechanical airway obstruction, enabling her extubation. This case report demonstrated the dramatic response of a large thyroid lymphoma to R-CHOP therapy, reducing the thyroid size and its fatal obstructive complications, including mechanical airway obstruction, within a few days of the initiation of R-CHOP therapy.

Small-Cell Malignancies of Thyroid: Challenge Solved?

"Small-cell malignancies of thyroid" is an unsolved dilemma. This term represents an umbrella terminology in thyroid, encompassing for a small group of tumors in which some of them are well-recognized tumors like medullary thyroid carcinoma, poorly differentiated thyroid carcinoma, and primary thyroid lymphomas and teratoma, whereas the remaining are less known as primary neuroendocrine carcinoma of thyroid, primary extraskeletal Ewing family tumors, and adamantinoma-like Ewing sarcoma. When the issue comes to evaluate a cytological sample predominantly composed of small-cell morphology, metastatic small-cell carcinomas to thyroid also should be excluded. In this review, our group focused on the main cytomorphological and clinical clues of each entity that help to set up a correct differential diagnosis. The literature discussions were also included for the entities that are not yet recognized by the mother publication WHO. A key point of the issue's simple algorithm based on FNAC with small-cell morphology of thyroid was suggested by the authors.

DLBCL of bilateral submandibular glands and MALToma of thyroid-A rare coexistence

Involvement of the bilateral submandibular glands and thyroid by the same lymphoma simultaneously has been reported in the literature. However, two different types of lymphomas presenting simultaneously at different sites have never been reported. This case report highlights this rare occurrence. A 65-year-old female, a known case of Hashimoto's thyroiditis with raised anti-TPO antibodies, presented with thyroid swelling for 1 year and bilateral submandibular swelling for 3 years. FNAC and flow cytometry showed features of mucosa-associated lymphoid tissue lymphoma in the thyroid gland, whereas the bilateral submandibular glands showed features of diffuse large B cell lymphoma. Histopathology and immunohistochemistry from the submandibular swelling led to similar diagnoses as the flow cytometry.

Thyroid lymphoproliferative lesions in Asia

Primary thyroid lymphomas (PTLs) are rare and most commonly present as rapidly enlarging thyroid mass causing obstructive symptoms. Due to worldwide differences in clinical practices related to thyroid malignancy, this review was conducted to compare the clinicopathological and diagnostic modalities related to PTL and their similarities and differences between the Asian and Western countries. Using the search engine PubMed, published data on thyroid lymphomas was collected and reviewed. A total of 18 Asian and 22 Western studies were included. Most of PTLs were B-cell Non-Hodgkin lymphomas (NHL). While mucosa-associated lymphoid tissue (MALT) lymphoma was the commonest (41.1%) among Asians, diffuse large B cell lymphoma (DLBCL) (71.9%) predominated in the Western population. Some rare subtypes of PTL were also identified. Majority of all patients in Asian as well as Western studies presented with early stage (stage I/II) disease. Interestingly, when compared with Asian patients, a larger proportion of patients from the West presented with higher stage (stage III/IV) disease (12.2% vs. 3%). Ultrasonography (USG) and fine needle aspiration cytology (FNAC) in addition to histological examination usually by core needle biopsy and in some by open procedures were used for the diagnosis of PTL in both the cohorts. The various ancillary techniques used were immunocytochemistry (ICC), flowcytometry (FC), immunohistochemistry (IHC), and molecular testing. The use of ancillary techniques for PTL diagnosis was more common in the West compared to Asia and markedly increased the sensitivity of cytology to diagnose PTL. Treatment and prognosis largely depend upon the subtype of PTL and stage at presentation. To conclude, from the available published literature, there is an apparent difference between Asian and Western cohorts in the histological type and stage of presentation of PTL, but the results may be affected by publication and selection bias. Also, advanced ancillary techniques are more commonly adopted in the West.

Diagnosis methods and treatment strategy for primary thyroid lymphoma: a retrospective analysis of 41 cases in China

Primary thyroid lymphoma (PTL) is a rare malignant tumor. It can manifest as a rapidly growing mass and produce various compression symptoms. However, PTL is easily missed or misdiagnosed for the lack of standardized diagnostic methods. Therefore, it is very necessary to analyze the diagnosis methods and treatment strategy of PTL to clarify the guide of diagnosis and treatment. In this study, we retrospectively analyzed PTL patients to determine their clinical, ultrasound and histological features. Forty-one PTL cases were analyzed. The pathological results of all cases were B-cell-derived non-Hodgkin's lymphoma. In these patients, 12 were mucosa-associated lymphoid tissue lymphomas, and 24 were diffuse large B-cell lymphomas. Through the analysis of the clinical, ultrasonographic and histological features of 41 patients with PTL, and the discussion of treatment strategies, we support that middle-aged women with a history of Hashimoto's thyroiditis should pay more attention to the possibility of PTL if they have a swelling neck. Thyroid function tests and neck ultrasound are routine examinations. Core biopsy is an important diagnostic method. PTL treatment is mainly based on radiotherapy and chemotherapy, and surgery is not the first choice.

The diagnosis of primary thyroid lymphoma by fine-needle aspiration, cell block, and immunohistochemistry technique

AIM

Primary thyroid lymphoma (PTL) is a rare malignant disease. Its prognosis depends on early diagnosis. The role of fine-needle aspiration (FNA), including smear cytology, cell block (CB) techniques, and immunohistochemistry (IHC) sections in the diagnosis of PTL is still unclear. Here we reported 19 cases of PTL and literature review to evaluate the diagnostic accuracy for lymphoma by cytology.

METHODS

Our study retrospectively reviewed 19 patients diagnosed with PTL at the affiliated hospital of Southwest Medical University in China from June 2011 to May 2019. According to the Bethesda system for reporting thyroid cytopathology, the CB sections were evaluated for the presence of single tumor cells. IHC was performed on CB.

RESULTS

The diagnostic accuracy for PTL of FNA, CB with smears, and the joint application of the three methods (FNA + CB + IHC) of our study with 19 cases was 68.4% (13/19), 83.3% (15/18), and 100% (17/17), respectively.

CONCLUSION

The present study demonstrates that FNA has low sensitivity in diagnosing PTL, but the joint application of FNA, CB, and IHC might provide high diagnostic accuracy for lymphoma and should be applied in all cases where the clinical suspicion is high regardless of the FNA findings.

Progressively Enlarging Goiter: Case Reports of Primary Thyroid Lymphoma and Literature Review

Primary thyroid lymphoma (PTL) is an exceptionally rare and highly aggressive potentially curable malignant disease. We report three typical cases of PTL referred to our hospital. All three cases had long history of Hashimoto's thyroiditis, and presented with progressively enlarging neck mass. The first two cases were confirmed by surgical biopsy to be diffuse large B cell lymphoma, and received radiotherapy combined with chemotherapy, or received only chemotherapy. The third case was confirmed by core needle biopsy to be mucosa-associated lymphoid tissue lymphoma, and received radiotherapy. In summary, confirmation of PTL diagnosis is essential for further clinical decisions. Core biopsy should be one of the most important methods to make the diagnosis of PTL, while the use of fine needle aspiration cytology alone is still limited in diagnosing PTL.

Ultrasonography in the Diagnosis and Monitoring of Therapy for Primary Thyroid Lymphoma

This study aims to evaluate the value of ultrasonography in the diagnosis, treatment, and follow-up of primary thyroid lymphoma. The clinical data of 12 patients, who were pathologically confirmed with thyroid lymphoma and treated in our hospital, were retrospectively analyzed. Ultrasonography was performed on the thyroid and neck lymph nodes, and the sonographic features of the lesions were recorded. During the course of the diagnosis and treatment of lymphoma, the patients were monitored and followed up by ultrasonography. The sonographic features of 12 patients with 20 lesions revealed hypoechoic masses, within which "strip-shaped" and "grid-shaped" high echoes were observed, and echoes behind masses were not attenuated. Furthermore, a small amount of blood flow signals were observed. Six patients received thyroidectomy. Among these patients, one patient relapsed. Six patients underwent chemotherapy. Among these patients, 2 patients relapsed and received chemotherapy again. Ultrasound can guide the biopsy of suspicious lymphoma lesions and provide accurate information on treatment effects and tumor recurrence for patients with thyroid lymphoma after treatment, especially after chemotherapy.

Clinical features associated with high pathological grade in primary thyroid lymphoma

This study aimed to identify clinical features associated with high pathological grade (HG) in primary thyroid lymphoma (PTL), through a systematic review and meta-analysis. Electronic databases were searched for studies assessing PTL. Extracted data were age, sex, lymph node involvement, symptoms, lymphocytic thyroiditis, serum tumor markers; the association with HG was assessed by using odds ratio (OR), with a significant p-value<0.05. Twenty-four studies with 1916 PTLs were included. HG was significantly associated with age≤55 (OR = 0.54; p < 0.0001); female sex (OR = 1.31; p = 0.02), lymph node involvement (OR = 2.23; p < 0.00001), compressive symptoms (OR = 2.61; p < 0.0001), absence of lymphocytic thyroiditis (OR = 0.45; p = 0.0002), and increased LDH levels (OR = 4.90; p < 0.00001), but not with age>60 (OR = 0.74; p = 0.24), age>70 (OR = 1.16; p = 0.66), and B symptoms (OR = 1.30; p = 0.54). In conclusion, Age≤55, female sex, lymph node involvement, compressive symptoms and absence of lymphocytic thyroiditis may be predictive factors for HG in PTL. On the other hand, B symptoms does not seem to be associated with pathological grade.

[A retrospective analysis of 12 cases of primary thyroid lymphoma]

OBJECTIVE

To discuss the clinical characteristics and diagnostic and therapeutic considerations of primary thyroid lymphoma (PTL) by reviewing PTL cases.

METHODS

In the study, 12 cases of PTL diagnosed and treated in Peking University First Hospital between January 1995 and September 2015 were identified. The clinical characteristics, management experiences and prognosis of these cases were reviewed retrospectively.

RESULTS

A total of 12 PTL patients (four males and eight females) were collected, with an average age of 63 years (42 to 81 years) at the time of diagnosis. The average time to clarify diagnosis was 5 months (0.5 to 24 months). Eleven patients presented with a rapidly growing neck mass and visited surgical department, except one complained of coughing and suffocated. Seven patients were hypothyroid, and four were euthyroid at the time of diagnosis. In sonography of 11 cases, nine showed bilateral nodules, with an average diameter of 3.87 cm. Pathologic diagnosis of non-Hodgkin's lymphoma was confirmed in all the 12 cases by means of partial thyroidectomy (four) or core needle biopsy (eight). The pathological subtypes were diffuse large B cell lymphoma in nine patients, mucosa-associated lymphoid tissue lymphoma (MALToma) in two, and small B cell lymphoma in the other one patient. Five patients were concomitant with Hashimoto's thyroiditis. Eleven patients received chemotherapy. Only one patient did not have any further treatment after operation due to an inertia type of tumor. The median overall survival time was 24 months (1-117 months), three patients died. Among the patients who survived, seven completed chemotherapy without disease progression, one MALToma case did not receive chemotherapy after thyroidectomy but was still alive with PTL, and one patient just finished his second course of chemotherapy.

CONCLUSION

The diagnosis of PTL should be considered when dealing with rapidly growing goiters in elder female Hashimoto's thyroiditis patients whose B ultrasound indicates hypoechogenicity in thyroid nodules or parenchyma, especially with lymphadenopathy and tracheal compressions. Timely use of coreneedle biopsy on suspicious cases can avoid unnecessary surgical trauma, and chemotherapy is the main treatment.

Characteristics and natural course of hypoechoic thyroid lesions diagnosed as possible thyroid lymphomas by fine needle aspiration cytology

Background

There is little information regarding the natural course of hypoechoic thyroid lesions that are probable or possible thyroid lymphoma based on fine needle aspiration cytology (FNAC) results.

Methods

Sixty-five patients who were diagnosed as probable or possible thyroid lymphoma by ultrasonography (US) and FNAC were investigated. Forty-three patients with strong suspicion underwent thyroid surgery for the diagnosis at our hospital, and 22 patients were followed up with periodic US examination. Thyroid lymphoma was definitely diagnosed in 41 out of 43 patients who underwent thyroid surgery, and such patients were defined as Group A. The outcomes of 22 patients who were followed up without an immediate therapy were analyzed. Their hypoechoic lesions decreased in size (n = 10) or disappeared (n = 2) in 12 of 22 patients, and such patients were defined as Group B. Patients in Group A and B were compared using the Kuma Hospital-US classification (USC), the diagnostic categories of the Bethesda System for Reporting Thyroid Cytopathology, and the κ/λ deviation of the immunoglobulin light chain in the FNAC specimens. Mann-Whitney U-test and chi-squared test (with Yate’s continuity correction) were used to compare the two groups.

Results

The USC of < 3.5 [9/12 (75.0%) in Group B; 10/41 patients (24.4%) in Group A] and the κ/λ deviation ratio of < 3.40 [11/12 (91.7%) in Group B; 17/41 patients (41.5%) in Group A] were significantly more frequent (p < 0.01), and the FNAC of ‘benign’ or ‘atypia of undetermined significance or follicular lesion of undetermined significance (AUS)’ with a comment of possible lymphoma [9/12 (75.0%) in Group B; 12/41 patients (29.3%) in Group A] was significantly more frequent (p < 0.05) in Group B than Group A.

Conclusions

Our study suggests that some hypoechoic thyroid lesions that are possible thyroid lymphoma based on US and FNAC might decrease in size or disappear during the careful observation.

Identification of Cytological Features Distinguishing Mucosa-Associated Lymphoid Tissue Lymphoma from Reactive Lymphoid Proliferation Using Thyroid Liquid-Based Cytology

OBJECTIVE

To identify cytological differences between mucosa-associated lymphoid tissue lymphoma (MALT-L) and nonneoplastic lymphocytes using thyroid liquid-based cytology (LBC).

STUDY DESIGN

We observed LBC and conventional specimens from 35 MALT-L cases, 3 diffuse large B-cell cell lymphoma (DLBCL) cases, and 44 prominent nonneoplastic lymphocytic infiltration cases.

RESULTS

In MALT-L cases, the incidence of lymphoglandular bodies in the LBC specimens was lower than that in the conventional specimens (p < 0.001). Moreover, the nuclear sizes in LBC specimens were larger than those in conventional specimens. In 62.9% of the MALT-L and all DLBCL specimens, large nuclei were present in > 10% of the lymphoid cells in LBC specimens. Two cases with prominent nonneoplastic lymphocytic infiltration also exhibited these findings. In LBC specimens, swollen naked nuclei with less punctate chromatin patterns and thin nuclear margins were observed in 92.1% of lymphoma and 20.5% of prominent nonneoplastic lymphocytic infiltration. Elongated nuclei were significantly more apparent in thyroid lymphoma than in prominent nonneoplastic lymphocytic infiltration (p < 0.001), with a significantly higher incidence in LBC specimens than in conventional specimens (p < 0.001).

CONCLUSIONS

Lymphoglandular bodies are not reliable markers for lymphoma diagnosis using LBC specimens. Large, swollen naked, and elongated nuclei are useful in distinguishing thyroid lymphoma from nonneoplastic lymphocytes in LBC specimens.

Surgical Treatment of Primitive Thyroid Lymphoma

Aims and Background

Primitive thyroid lymphoma, although rare, is becoming more frequent. Its incidence is increasing, from 0.5% in the sixties to 1-5% of all thyroid neoplasms today. The diagnosis of such neoplasms is not always straightforward. In fact, it is often the result of pathologic findings on a gland resected for an apparently benign disease. Surgical dissection may prove more complicated than in standard cases of thyroidectomy for the possible tight adhesions existing between the gland's capsule and the surrounding structures. In cases of capsular infiltration, postoperative external local radiotherapy is indicated.

Methods

A retrospective observational analysis was performed to establish whether patients with incidental thyroid lymphomas who underwent total thyroidectomy for another pathology had major surgical complications and worse prognostic results than patients with an accurate preoperative diagnosis.

Results

Six cases of thyroid lymphoma were retrospectively reviewed: 4 diffuse large B-cell lymphomas and 2 MALT lymphomas. Of these, 2 were correctly preoperatively identified by fine-needle aspiration biopsy and 4 were an unexpected finding at histology: 3 cases of total thyroidectomy carried out for huge hypothyroid goiter in patients affected by Hashimoto's thyroiditis and in 1 case of total thyroidectomy carried out for anaplastic carcinoma in a patient affected by Hashimoto's thyroiditis.

Conclusions

In our experience, a correct preoperative diagnosis was extremely difficult (33%). In patients who underwent fine-needle aspiration, a correct diagnosis was made in 66% of cases. All patients with stage IE lymphoma who underwent total thyroidectomy had equivalent surgical complications and prognosis.

Aberrant expression of CD20 in thyroid cancer and its clinicopathologic significance

CD20 is the first-line diagnostic marker of B-cells, which serves as the target of the therapeutic monoclonal antibodies in B-cell lymphomas and leukemias. Recently, aberrant CD20 expression has been described in a small series of papillary thyroid carcinomas (PTCs). We aimed to evaluate CD20 immunoexpression and to perform clinicopathologic correlation in a large set of thyroid tumors, including a cohort of high-grade thyroid cancer. A total of 625 cases of thyroid tumor comprised tissue microarrays of 538 PTCs and 47 follicular adenomas, and whole-slide sections of 40 aggressive thyroid carcinomas (10 radioiodine-refractory PTCs and 8 poorly differentiated, 5 anaplastic, and 17 medullary thyroid carcinomas) were immunostained with anti-CD20 monoclonal antibody. BRAF^V600E mutation was tested by direct sequencing in 478 cancers. Our study found that a small subset of PTCs (<10%, mainly of classic variant) exhibited aberrant membranous expression of CD20. These tumors displayed less aggressive histological features and had a lower prevalence of BRAF^V600E mutation. We also discovered that CD20 expression was maintained in 6%-20% of aggressive thyroid cancers but not observed in follicular adenomas. All CD20-positive tumor cells were negative for CD79a and PAX5. Aberrant expression of CD20 by thyroid cancer cells may present a diagnostic pitfall in cytologic evaluation of thyroid and cervical masses. Residual expression of CD20 in aggressive cancers may offer promise for translational implications, which merits further experimental investigation.

Commonly forgotten complication of Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) is a frequently encountered condition in clinical practice and management is generally uncomplicated with patients on a stable dose of thyroxine supplementation. However, complications of thyroid lymphoma can develop, though it is rare and hence commonly forgotten by physicians. We present a case of a patient with HT who developed thyroid lymphoma. A 61-year-old woman presented with an enlarged goitre complicated by compressive symptoms and was diagnosed with HT. She was treated with stable dose of thyroxine but her constitutional symptoms of weight loss prompted further investigations and diagnosis of diffuse large B-cell lymphoma was eventually made. She underwent chemotherapy and adjuvant radiotherapy and is currently in remission 1 year post-treatment. There should be an increased index of suspicion of primary thyroid lymphoma in patients with HT for early diagnosis and treatment for better outcomes.

Clinical Presentation and Diagnostic Challenges of Thyroid Lymphoma: A Cohort Study

BACKGROUND

Thyroid lymphoma is a relatively rare disease often posing a diagnostic challenge. Reaching the final diagnosis can be delayed if insufficient biopsy material is obtained for immunohistochemistry analysis. The aim of this study was to evaluate the clinical, biochemical, and radiological features of thyroid lymphoma.

METHODS

A retrospective analysis was conducted of all Mayo Clinic patients evaluated between 2000 and 2014 who had a tissue biopsy positive for thyroid lymphoma.

RESULTS

Seventy-five subjects had biopsy-proven thyroid lymphoma, and 62.7% were primary thyroid lymphomas. The median age at diagnosis was 67 years (range 20-90 years). A total of 50.7% were male, and 54.7% had a history of Hashimoto's thyroiditis. Presenting symptoms included neck mass (88%), dysphagia (45.3%), and hoarseness (37.3%). The typical ultrasound appearance consisted of a solid, hypoechoic mass with increased vascularity and variable edge characteristics. Fine-needle aspiration (FNA) biopsies were abnormal in 70.7% of cases, and 42% indicated a specific lymphoma subtype. The diagnosis was confirmed in 53.3% by core biopsy, in 21.3% by thyroidectomy (partial or total), in 12% through incisional biopsy, and in 12% by lymph node biopsy. Core biopsy had a higher sensitivity compared with FNA (93% vs. 71%, p = 0.006).

CONCLUSION

A rapidly enlarging neck mass in the setting of Hashimoto's thyroiditis should raise suspicion for thyroid lymphoma. Radiologically, this usually presents as a large, unilateral, thyroid-centered mass, hypoechoic by ultrasound, and expanding into adjacent soft tissues. Core-needle biopsy should be the first diagnostic test to expedite reaching the final diagnosis and decrease patient burden of additional tests and interventions.

Development of Primary Thyroid Lymphoma during an Ultrasonographic Follow-up of Hashimoto's Thyroiditis: A Report of 9 Cases

We herein experienced 9 patients with primary thyroid lymphoma that developed during 3-18 years of ultrasonographic follow-up of Hashimoto's thyroiditis. All nine patients had localized mucosa-associated lymphoid tissue (MALT) lymphoma. Two patients had diffuse type, one had mixed type, and six had nodular type according to the ultrasonographic classification. A clearly enlarging goiter was observed before the diagnosis of lymphoma in 3 patients. An enlarging goiter was not apparent in the remaining 6 patients with nodular type lymphoma, however, the emergence or enlargement of a hypoechoic nodular lesion was observed. Thyroid MALT lymphoma may be diagnosed early by an ultrasonographic follow-up of Hashimoto's thyroiditis.

Coexistence of Papillary Thyroid Carcinoma With Thyroid MALT Lymphoma in a Patient With Hashimoto's Thyroiditis: A Clinical Case Report

Papillary thyroid carcinoma (PTC) is the most common type of thyroid neoplasias; however, primary thyroid gland lymphoma (PTL) is uncommon and their simultaneous occurrence is very rare.Herein, we reported a 25-year-old female patient with Hashimoto's thyroiditis (HT), who developed a small goiter with a palpable 1.2-cm nodule in the right lobe. A fine-needle aspiration (FNA) biopsy revealed atypical follicular epithelial cells and lymphoid cells in a background of lymphocytic thyroiditis. A total thyroidectomy was performed. The pathology showed multicentric papillary thyroid carcinoma, concomitant thyroid mucosa-associated lymphoid tissue (MALT) lymphoma, and Hashimoto's thyroiditis. Postoperatively, he received chemotherapy and radioactive iodine ablation treatment. Nowadays the thyroglobulin of the patient is undetectable, without recurrences at 2 years of follow-up.It is concluded that the PTC and MALT lymphoma can exist concomitantly, especially in patients with HT. For the diagnostic workup and optional management of this rare coexistence, a multidisciplinary approach and close surveillance are needed.

Thyroid lymphoma: A case report and literature review

Thyroid lymphoma is an unusual pathology. Different subtypes of lymphoma can present as primary thyroid lymphoma. This review illustrates via imaging, findings and treatment the need for accurate diagnosis and timely treatment. Patients and methods: patient’s chart, pathological findings and radiological images were reviewed in a retrospective analysis. Over several days, this 80 years old woman developed airway obstruction and rapid enlargement of her thyroid secondary to diffuse large B-cell lymphoma. She rapidly responded to her oncological protocol. Primary thyroid lymphoma is a rare disease. It is an important diagnosis to consider in patients presenting with rapidly enlarging neck masses. It is a treatable condition with fairly favorable overall survival even with the most aggressive histological subtypes.

Core needle biopsy could reduce diagnostic surgery in patients with anaplastic thyroid cancer or thyroid lymphoma

OBJECTIVE

To evaluate the diagnostic performance of fine needle aspiration (FNA) and core needle biopsy (CNB) in patients with anaplastic thyroid cancer (ATC) or thyroid lymphoma (TL).

METHODS

Between January 2000 and March 2012, 104 patients were diagnosed with ATC or TL by means of ultrasound (US)-guided FNA, CNB, or surgery. This study ultimately included 99 patients with ATC (n = 59) or TL (n = 40). We evaluated the sensitivity and positive predictive value of FNA and CNB for the diagnosis of ATC and TL, and compared the rates of diagnostic surgery between FNA and CNB.

RESULTS

FNA was used in 83 patients, and CNB was used in 32 patients initially (n = 16), after FNA results (n = 8), or simultaneously with FNA (n = 8). CNB achieved sensitivity of 87.5 % (28/32) and positive predictive value of 100.0 % (28/28) for the diagnosis of ATC and TL. The respective values for FNA were 50.6 % (40/79) and 90.9 % (40/44). The rate of diagnostic surgery was significantly lower after CNB (4/32, 12.5 %) than after FNA (28/79, 35.4 %) (p = 0.020).

CONCLUSIONS

CNB was able to reduce unnecessary diagnostic surgery in patients with ATC or TL by virtue of its superior diagnostic sensitivity and positive predictive value compared to FNA.

KEY POINTS

• Diagnostic sensitivity and PPV for CNB were 87.5 % and 100.0 %, respectively. • The respective values for FNA were 50.6 % and 91.0 % for ATC and TL. • Diagnostic surgery rates were reduced after CNB compared to FNA (p = 0.020).

Thyroid nodule: first manifestation of chronic lymphocytic leukaemia

The presence of chronic lymphocytic leukaemia (CLL) cells in the thyroid gland is most likely due to a secondary involvement by a systemic disease. The reported incidence of CLL involving the thyroid is extremely low, representing about 3-4% of all thyroid lymphoproliferative neoplasm. We report a rare case of CLL presenting initially in the thyroid gland. Systemic disease was detected as a result of thyroid investigation. An 85 years old woman, with multinodular goiter without adenophaties, was referred to our department, carrying a fine needle aspiration biopsy (FNAB) report of a private institution referring "lymphoid monomorphic proliferation" and suggesting a "Core-needle biopsy" for further investigation. She was euthyroid (TSH-0.5 uU/mL (0.4-4.0), thyroid antibodies negative, including TRab). The patient denied systemic symptoms and at physical examination there were no adenophaties or organomegalies. FNAB analysis was repeated. Although the patient denied constitutional symptoms and there were no relevant findings in physical examination, technetium 99m thyroid gamagraphy (GG) and blood count were additionally asked. FNAB analysis concluded lymphocytic tiroiditis, but thyroid GG revelled global hypocaptation and blood count showed 173.4 x 109 leukocyte/L with 94% lymphocyte. An ecoguided FNAB with flow cytometry identified thyroid infiltration by monotonous population of blasts with phenotype consistent with CLL/malignancy of mature B-cells. CLL/malignancy of mature B-cells was also detected in peripheral blood analysis, suggesting systemic disease with secondary thyroid involvement. The patient started chemotherapy with rituximab and chlorambucil with good response. Pos-treatment GG revelled "Increased levels of uptake in the middle third of the right lower lobe, with low uptake of the remaining parenchyma". In conclusion, good communication with the pathologist can improve diagnostic accuracy and dictate appropriate therapy. The use of techniques such as flow cytometry, immunoglobulin gene rearrangements, and immunohistochemistry has improved diagnostic accuracy and obviated more invasive procedures, such as core needle or open surgery biopsy. Apart from chemotherapy, immunochemotherapy with anti-CD20 and anti-CD52 monoclonal antibodies can be used in the treatment of CLL.

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.

Thyroid lymphoma: recent advances in diagnosis and optimal management strategies

Primary thyroid lymphoma is rare, composing approximately 5% of all thyroid malignancies and less than 3% of all extranodal lymphomas. It typically presents as a rapidly enlarging goiter with associated compressive symptoms. Thyroid ultrasound and fine needle aspiration cytology, using flow cytometry and immunohistochemistry, remain the main modalities used to confirm the presence of lymphoma. The increasing use of an ultrasound-guided core biopsy to achieve an accurate diagnosis has further limited the role of surgery. An open surgical biopsy may still be required not only for definitive diagnosis but also to confirm the subtype of lymphoma. There are limited numbers of randomized or prospective trials to guide management, and controversy remains over optimal treatment. Treatment and prognosis of this disease can be dichotomized into two separate groups: pure mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma (DLBCL) or mixed subtypes. Early stage (stage IE) intrathyroidal MALT lymphomas typically have an indolent course and may be treated with single-modality surgery, radiotherapy, or a combination of both. DLBCLs are more aggressive, and survival outcomes are highest with multimodal therapy incorporating monoclonal antibodies, chemotherapy, and radiotherapy. The prognosis is generally excellent but can be varied because of the heterogeneous nature of thyroid lymphomas. The aim of this paper is to discuss the changes in diagnostic modalities and to focus on the recent alterations in the management of this rare disease, including targeted therapies as well as the more limited role of the endocrine surgeon.

Thyroid nodule as a first manifestation of Hodgkin lymphoma-report of two cases and literature review

Lymphomas account for less than 5% of thyroid malignant lesions. Vast majority of them are B-cell non-Hodgkin lymphomas (NHL), while Hodgkin lymphoma (HL) is extremely rare. Here we present two cases of HL, at baseline manifesting as a thyroid lesion. First patient, 29-year-old pregnant female, initially suspected for metastatic medullary thyroid cancer, was eventually diagnosed with mixed cellularity type of thyroid HL. Second patient, 22-year-old woman with suspicion of advanced thyroid cancer, was in the end diagnosed with an extra-lymphatic classical HL of the thyroid. In both cases, despite repeated fine-needle aspiration biopsy, cytological examination gave inconclusive or misleading results. On histopathological examination, thyroid tumor cells were positive for CD15 and CD30 antigen, which is typical for Reed-Sternberg cells. In the report authors also discuss difficulties in management as well as potential importance of novel methods such as FISH, PCR and other molecular techniques in diagnostics of thyroid lymphomas.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2896947559559648.

Case report: rare case of infiltration of small lymphocytic B-cell lymphoma in the thyroid gland of female patient with B-cell chronic lymphocytic leukemia (CLL-B/SLL-B)

The article presents a case of 57-year-old woman with the infiltration of rare small lymphocytic B cell lymphoma in the thyroid gland. Initially, the patient was followed-up due to chronic lymphocytic B-cell leukemia diagnosed on the basis of histopathological examination of cervical lymph node. Eight months later, general symptoms occurred along with lymphocytosis and exacerbation of lesions in lymph nodes, and therefore, chemotherapy was started according to COP regimen. After four chemotherapy cycles, further progression of the disease was observed during chemotherapy. Computed tomography (CT) performed at that time showed generalized lymphadenopathy and the presence of an irregular area in left thyroid lobe. On palpation, the thyroid was asymmetrical, with enlarged left lobe and palpable lymph node packages on the left side of the neck. The levels of thyroid hormones and anti-thyroid antibodies were normal. Ultrasound examination of the thyroid gland showed non-homogeneous hypoechogenic structure of the left lobe and complete focal remodeling. Cytological examination of left-lobe lesion obtained during fine needle aspiration biopsy showed multiple small lymphoid cells, suggestive of small lymphocytic lymphoma. To confirm this diagnosis, flow cytometry of the biopsy material sampled from the left lobe was performed showing B cellimmunophenotype: CD19+/CD20+/CD22 dim/FMC-7, CD23+/CD5+, sCD79b-+, CD38-, CD10-, kappa and lambda-/weak reaction. The results of flow cytometry of the thyroid bioptate and blood were nearly identical, confirming leukemic nature of the infiltration in left thyroid lobe. Cytogenetic findings included the presence of 17p deletion (TP53 gene). The patient received immunochemotherapy with alemtuzumab. The progression of the disease occurred in the sixth week of therapy. The treatment was discontinued after 8 weeks due to worsening of patient's general status. The patient died 15 months after the diagnosis.

A rare case of Hodkin's lymphoma of the mediastinum imitating retrosternal goiter--retrospective analysis of the diagnostic process

Primary extranodal sites of development of lymphoid neoplasms are rare and concern about 5% of patients with Hodgkin's lymphoma. Extranodal development is more common in non Hodgkin's lymphoma and may reach 33%. A 27-year-old woman was diagnosed by a cardiologist for a short breath. On the physical examination no other abnormalities were observed. Echocardiography, performed by cardiologist, revealed a large tumor, overlaying the right ventricle and compressing the pulmonary trunk. Chest X-ray, ultrasound and CT-scan confirmed diagnosis. In fine needle aspiration clear, lucid fluid was obtained. Scintygraphy of the neck and thorax showed accumulation of the marker in the properly placed but enlarged thyroid gland. Patient was qualified for surgical treatment - cervicotomy and sternothomy were performed. The histopatological exam of the tumor revealed Hodgkin's lymphoma of the mediastinum (classical subtype NS-1). Following the surgery, adjuvant therapy was instituted. After the treatment PET-CT-scan did not show any kind of non-physiological radiomarker's accumulation in the monitored regions of the body and in in three-years follow-up the patient shows no signs of recurrence.

Co-occurrence of papillary thyroid carcinoma and primary lymphoma of the thyroid in a patient with long-standing Hashimoto's thyroiditis

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer, whereas mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid gland is uncommon. Simultaneous occurrence of both disease entities is very rare.

PATIENT FINDINGS

A 59-year-old man with known hypothyroidism from Hashimoto's thyroiditis (HT) was seen for thyroid nodules. A thyroid ultrasound revealed a heterogeneous thyroid gland with two hypoechoic nodules, one in the right aspect of the isthmus measuring 2.0 cm×3.2 cm×1.7 cm and another one in the left lobe measuring 1.4 cm×1.3 cm×1.2 cm. A fine-needle aspiration (FNA) of the right-sided nodule revealed atypical epithelial cells and atypical lymphoid cells in a background of lymphocytic thyroiditis; FNA of the left-sided nodule showed findings of PTC. A total thyroidectomy was performed. Lymph node dissection was not performed. Pathology showed extranodal marginal zone B-cell lymphoma of MALT type with extreme plasmacytic differentiation in the right nodule and PTC in the left nodule (pT1b Nx Mx). Postoperatively, he underwent radioactive iodine ablation treatment. There was only minimal neck uptake on the post-treatment scan. Further work-up did not show any evidence of extrathyroidal lymphoma. Seven years after the surgery, the patient had no evidence of recurrence of either malignancy.

SUMMARY

PTC is the most prevalent thyroid cancer and has an excellent prognosis. Primary thyroid lymphoma is rare and accounts for <5% of all thyroid cancers. Among the primary thyroid lymphomas, MALT lymphoma tends to have a more indolent course and a better prognosis. PTC and MALT lymphoma have been associated with HT. FNA has been validated in several studies for the diagnosis of MALT lymphoma; however, distinguishing MALT lymphoma from HT remains a challenge due to their histological similarities. The treatment of MALT lymphoma remains controversial; however, surgery is generally accepted in the early-stage MALT lymphoma as was performed in the present case.

CONCLUSION

Since HT is associated with PTC and MALT lymphoma, patients with HT deserve careful surveillance for both disease entities. In our patient, the management of one malignancy did not affect the management of the other, and the prognosis did not seem to be affected.

Primary thyroid mucosa-associated lymphoid tissue lymphoma; a clinicopathological study of seven cases

PURPOSE

Primary thyroid mucosa-associated lymphoid tissue (MALT) lymphoma is a very rare subgroup of thyroid lymphoma, accounting for about 6 to 28% of all primary thyroid lymphomas. The purpose of this study was to evaluate its clinicopathological features and treatment outcomes.

METHODS

We identified seven patients with thyroid MALT lymphoma who were treated between January 1997 and December 2007, and reviewed their clinicopathological features and follow-up outcomes.

RESULTS

There were five female and two male patients, and their mean age was 73 years. All patients presented with palpable neck mass. Two patients had hoarseness and dyspnea. All patients had a history of Hashimoto's thyroiditis with a mean of 175 months. Malignant lymphoma was suspected in only three patients using core needle biopsy. Four patients underwent thyroidectomy in the absence of preoperative pathologic confirmation, and histologic diagnosis was obtained after surgery. As initial treatment, complete surgical resection was performed in five patients, radiotherapy in one, and a combination of chemotherapy and radiotherapy in one. Six patients were alive for the mean follow-up period of 66 months and one patient died of unrelated causes. There were neither recurrences nor disease-specific mortalities.

CONCLUSION

When primary thyroid MALT lymphoma occurs in the thyroid or is confined to the neck, it responds well to local treatment such as surgical resection and external beam radiation therapy.

Sonographic appearances of mucosa-associated lymphoid tissue lymphoma of the submandibular gland confirmed with sonographically guided core needle biopsy

A 71-year-old man presented with mucosa-associated lymphoid tissue (MALT) lymphoma of the submandibular gland 52 months after initial diagnosis of MALT lymphoma of the lung. Ultrasonography showed a well-demarcated, markedly hypoechoic, heterogeneous solid mass with linear echogenic strands and hypervascularity. Ultrasound-guided core-needle biopsy demonstrated histological findings of MALT lymphoma. Sonographic features of MALT lymphoma of the submandibular gland are characteristic and ultrasound-guided core-needle biopsy may be a suitable replacement for surgical biopsy.

Clinical characteristics of primary thyroid lymphoma in Koreans

Primary thyroid lymphoma is a very rare tumor and its prevalence is approximately 0.1% of all thyroid cancers in Korea. Its clinical experience is limited and not familiar to physicians. Therefore, we performed this study to investigate the clinical characteristics of primary thyroid lymphoma in Koreans. We retrospectively analyzed the medical records of the 44 patients with primary thyroid lymphoma from 1991 to 2006 at four major referral hospitals in Korea. Out of 44 patients, eight patients were male and 36 patients were female and their average age was 57 years. Fifty-six percent of patients had underlying Hashimoto's thyroiditis. All but two patients had non-Hodgkin's lymphoma with B cell origin, and eighty percent of patients presented with stage IE or IIE. Twenty-one of 44 patients (48%) had diffuse large B cell lymphoma (DLBCL) and 17 (39%) had MALT lymphoma. Malignancies originating from lymphoid cells were suspected in 10 of eighteen patients with DLBCL (56%) by using fine-needle aspiration cytology (FNAC), and no difference was noted compared with MALT lymphoma (64%). Compared with DLBCL, the patients with MALT lymphoma were more frequently presented with stage I disease (DLBCL vs. MALT lymphoma: 32% vs. 65%, P=0.04). Moreover, in contrast to DLBCL, most of the patients with MALT lymphoma achieved complete response with treatments (DLBCL vs. MALT lymphoma: 53% vs. 94%, P<0.01). Because of the low diagnostic accuracy of FNAC, thyroid biopsy should be considered for the diagnosis of thyroid lymphomas in suspicious cases. The patients with MALT lymphoma were more frequently presented with early stage diseases and this might lead to the favorable outcome to treatments than those with DLBCL.

Cytologic features of mixed papillary carcinoma and chronic lymphocytic leukemia/small lymphocytic lymphoma of the thyroid gland

We report a case of papillary thyroid carcinoma (PTC) and chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma of the thyroid gland. To the best of our knowledge, this is the first such case to be reported in the cytology literature. An 81-year-old male with known CLL presented for routine physical examination and was found to have a left-sided thyroid nodule. Thyroid ultrasound showed a calcified nodule. Fine-needle aspiration biopsy (FNAB) was performed and revealed PTC and an atypical lymphoid infiltrate that was suspicious for lymphoma. A partial thyroidectomy was performed and confirmed PTC with concurrent gland involvement by chronic lymphocytic leukemia/small lymphocytic lymphoma (SLL).