Primary thyroid lymphoma (PTL) is very rarely encountered in clinical practice, as it comprises less than 5% of all malignancies that arise from this organ [1] [2] [3]. Lymphomas that develop in the thyroid are almost always of B-cell origin, the most common being diffuse large B-cell lymphoma (DLBCL) and mucosa-associated lymphoid tissue (MALT) lymphoma, while follicular lymphoma, small lymphocytic lymphoma, Burkitt's lymphoma and Hodgkin's lymphoma are other recognized forms [1] [3]. PTL is principally diagnosed in the sixth and seventh decades of life, and a significant predilection toward female gender has been established [1] [2] [4] [5]. Furthermore, a markedly higher number of PTLs are diagnosed in patients with preexisting Hashimoto's thyroiditis, implying its important role in the pathogenesis of PTL [1] [3] [5] [6]. An enlarging painless mass in the neck, seen in almost 70% of cases, is the main clinical manifestation of PTL, and the mass can compress the adjacent structures in the neck, resulting in dysphagia, dyspnea, stridor, and hoarseness in 30-50% of patients [3] [4] [6]. In addition, constitutional symptoms of fever, weight loss, and night sweats, which are typical for B-cell lymphomas, may be present as well but are reported in only 10% of individuals [2] [3].

• Goiter

  METHODS: The sonographic findings for 13 surgically proven primary thyroid lymphomas were analyzed and compared to those for 27 nodular goiters. [ncbi.nlm.nih.gov]

  The typical presentation is a rapidly enlarging goiter with symptoms or signs of tracheal, esophageal or neck vein compression. In 10–20% there is a known goiter often with hypothyroidism. [endocrine-abstracts.org]

• Thyroid Nodule

  Thirteen (60%) patients presented with thyroid nodule(s). Eleven (50%) presented with aerodigestive tract obstructive symptoms. [ncbi.nlm.nih.gov]

  The clinical presentations include an enlarging neck mass, but patients may also present with symptoms of dysphagia, hoarseness and choking, or a cold thyroid nodule. [mayoclinic.pure.elsevier.com]

  Conclusions: Thyroid lymphoma is a rare cancer but must be considered in the differential diagnosis of patients with thyroid nodules or goiter specially if a Hashimoto’s thyroiditis is present. [endocrine-abstracts.org]

• Stridor

  We report the case of 71 year old woman who presented with severe inspiratory stridor due to a compressing primary thyroid lymphoma. [ncbi.nlm.nih.gov]

  Abstract Tumors originating in the neck are well-known causes of progressive dysphagia and dyspnea (including stridor), and thyroid lymphoma is an uncommon example. [uknowledge.uky.edu]

  Poor prognostic factors include advanced stage of the tumor ( stage IE), size greater than 10 cm, mediastinal involvement, rapid clinical growth, and the presence of dysphagia or stridor. [shifrinmd.com]

  We hereby conclude that, in a preexisting case of Hashimotos thyroiditis, PTL has to be ruled out especially if there is sudden increase in size, dysphagia, stridor, and hoarseness of voice. [cancerjournal.net]

• Inspiratory Stridor

  We report the case of 71 year old woman who presented with severe inspiratory stridor due to a compressing primary thyroid lymphoma. [ncbi.nlm.nih.gov]

• Tracheal Deviation

  Most patients demonstrate a rapidly enlarging mass and may show tracheal deviation on chest roentgenogram. Radioisotopic scanning of the thyroid often demonstrates a "cold" or "cool" process of decreased uptake in the affected area. [ncbi.nlm.nih.gov]

• Progressive Dysphagia

  Abstract Tumors originating in the neck are well-known causes of progressive dysphagia and dyspnea (including stridor), and thyroid lymphoma is an uncommon example. [uknowledge.uky.edu]

• Subcutaneous Nodule

  Isolated thyroid mass was seen in 3 patients, thyroid mass with cervical lymphadenopathy was found in 6 patients and 3 patients had thyroid mass with multiple subcutaneous nodules ( Table 2 ). [npplweb.com]

• Bilateral Leg Weakness

  The patient, a 42-year-old man, presented with chest discomfort and bilateral leg weakness of one week's duration. Physical examination of his neck showed a right-sided mass lesion. [ncbi.nlm.nih.gov]

• Proximal Muscle Weakness

  There was symmetric proximal muscle weakness, and 2/5 strength in upper and lower extremities. [ncbi.nlm.nih.gov]

• Neck Mass

  EVIDENCE SYNTHESIS: Primary thyroid lymphoma should be suspected in patients with a rapidly enlarging neck mass, especially in women with Hashimoto's thyroiditis. [ncbi.nlm.nih.gov]

  Painless neck mass Hoarseness Difficulty swallowing Signs of tracheal compression Diagnosis[edit] Thyroid lymphoma poses a diagnostic and therapeutic challenge. [en.wikipedia.org]

• Babinski Sign

  Babinski's sign was present bilaterally. Endocrinologic studies showed subclinical hypothyroidism. A thoracolumbar radiograph showed disc space narrowing. Thyroid sonography revealed a hypoechoic mass lesion in the right lobe of the thyroid gland. [ncbi.nlm.nih.gov]

• Hyperreflexia

  Neurologic examination revealed decreased muscle power and hyperreflexia in both lower legs. Babinski's sign was present bilaterally. Endocrinologic studies showed subclinical hypothyroidism. A thoracolumbar radiograph showed disc space narrowing. [ncbi.nlm.nih.gov]

Many reports have emphasized the benefit of early recognition of PTL, primarily because therapy is quite effective in its earlier stages [1] [2] [4] [5]. However, studies have shown that up to 36 months may pass from the onset of symptoms to the diagnosis, which markedly affects survival rates and treatment outcomes [1] [2] [3] [4] [5]. For this reason, a meticulous clinical workup must be performed in order to obtain enough evidence to raise clinical suspicion toward PTL. Firstly, patients should be asked about the course and progression of symptoms, whereas a detailed physical examination of the neck can result in palpation of a hard and smooth-surfaced mass [4]. If a mass is palpated, immediate employment of imaging techniques, such as ultrasonography (US), is necessary, and a hypoechoic homogeneous mass with an enhanced posterior echoes is highly suggestive of PTL [2] [4]. Based on US findings, PTL is further divided into nodular (unilateral and pseudocystic changes), diffuse (bilateral and possessing indistinct borders) and mixed, which shows multiple patchy lesions [4]. Because the diagnosis is not conclusive without a histopathological examination, a biopsy of the lesion, most commonly in the form of fine-needle aspiration (although core-incision and open biopsy are mentioned as possible methods as well), is the vital step in workup [1]. Not only does it confirm the diagnosis, but it also helps in determining the stage of the tumor, together with computed tomography (CT) and other imaging modalities [1] [2] [4] [5] [6]. Based on the extent of tumor involvement and its dissemination, PTL is classified into [3]:

• Stage I - Only local growth is observed.
• Stage II - Dissemination into the lymphatic system within the same side of the diaphragm.
• Stage III - Infiltration of distant lymph nodes and/or spleen.
• Stage IV - The presence of distant metastases.

• Mediastinal Mass

  Good luck and keep us posted Cheers 21 yr old male (Our Son) Diffuse Large B-Cell Non Hodgkins Lymphoma Stage 1A Mediastinal Mass 8cm x 7cm Diagnosed October 09 Started course of 6 x R-CHOP 14 in Nov 09 Course complete Jan 2010 Remission declared March [cancerforums.net]

• Left Pleural Effusion

  CT scans of thorax abdomen and pelvis were normal expect left pleural effusion. Bone marrow aspiration and biopsy were normal. With these findings patient was staged as IV and commenced on chemotherapy. [turkjem.org]

1. Gupta N, Nijhawan R, Srinivasan R, et al. Fine needle aspiration cytology of primary thyroid lymphoma: a report of ten cases. Cytojournal. 2005;2:21.
2. Xia Y, Wang L, Jiang Y, Dai Q, Li X, Li W. Sonographic Appearance of Primary Thyroid Lymphoma-Preliminary Experience. Björklund P, ed. PLoS One. 2014;9(12):e114080.
3. Peixoto R, Correia Pinto J, Soares V, Koch P, Taveira Gomes A. Primary thyroid lymphoma: A case report and review of the literature. Annals of Medicine and Surgery. 2017;13:29-33.
4. Stein SA, Wartofsky L. Primary thyroid lymphoma: a clinical review. J Clin Endocrinol Metab. 2013;98(8):3131-3138.
5. Verma D, Puri V, Agarwal S, Bhaskar A. Primary thyroid lymphoma: A rare disease. J Cytol. 2014;31(4):218-220.
6. Lee SC, Hong SW, Lee YS, et al. Primary thyroid mucosa-associated lymphoid tissue lymphoma; a clinicopathological study of seven cases. J Korean Surg Soc. 2011;81(6):374-379.