🌊Thyroid Lymphoma + Lymphoma

Question 1

Epidemiology

Answer 1

• Rare < 5 % of thyroid malignancies
• Almost always NHL B – cell type

Question 2

Classification of Lymphoma

Answer 2

Question 3

Etiology of Thyroid Lymphoma

Answer 3

• Hashimoto’s thyroiditis - only known risk factor (60x ↑ risk).
• Thyroid NHL is present in 50% patient with Hashimoto’s thyroiditis.
• Lymphomas occur when there is malignant transformation of normal lymphocytes that can reside in both lymphoid and nonlymphoid tissues including the thyroid gland.

Question 4

Presentation of Thyroid Lymphoma

Answer 4

Diffuse large B cell lymphoma (DLBCL) behaves in a more aggressive manner than the more indolent MALT and follicular lymphomas.

MALT lymphoma is a type of non-Hodgkin lymphoma (NHL). MALT stands for mucosa associated lymphoid tissue

• Duration of symptoms before diagnosis range from a few days to 36 months, with a shorter duration reported in those with DLBCL
• 90% rapidly enlarging goiter with compressive symptoms - dyspnea, dysphagia, stridor, and hoarseness.
• 12% of patients report pain over the thyroid
• 10% present as STN, occasionally slow growing (MALT lymphoma)
• 10% has B symptoms like fever, night sweats, weight loss (>10kg)
• 10% has hypothyroidism.
• Physical: Firm to hard, smooth surface, slight tender, fixed immobile - can be unilateral or bilateral.

Question 5

Investigation

Answer 5

TFT – majority euthyroid, can present as hypothyroid in 25%, ↑ anti TPO & anti TG

USG - Typically has pseudocyst hypoechoic areas.

• Nodular type - goiter is unilateral with internal echoes that are hypoechoic, homogeneous, and pseudocystic. Well-defined borders separate lymphomatous from nonlymphomatous tissues.
• Diffuse type - goiter is bilateral and hypoechoic, with indistinct borders between lymphomatous and nonlymphomatous tissues.
• Mixed type - multiple patchy, hypoechoic lesions.

Enhanced posterior echoes are present in all 3 types and help distinguish lymphoma from other types of thyroid lesions.

FNA - May not show lymphoma. Need IHC or flow cytometry. If still suspicious → CNB for definitive diagnosis.

CT Scan - for non-avid lymphomas. Of head, neck, chest, abdomen, and pelvis as the primary technique for staging.

Radioiodine scintigraphy or PET CT - for avid Lymphomas. Diffuse thyroid uptake is seen with Hashimoto’s thyroiditis.

Question 6

Histologic Type

Answer 6

• Diffuse large B cell lymphoma (DLBCL) - > 50%
• MALT lymphoma - 10–23%, can transform into DLBCL
• Follicular lymphoma - 10%
• Hodgkin’s lymphoma - 2%, (Reed-Sternberg cells)

Question 7

Ann Arbor Staging ( classification)

Answer 7

Question 8

Management of Thyroid Lymphoma

Answer 8

• Severe Airway compromise - 25% patients with Thyroid lymphoma.
  
  • Chemotherapy (Rituximab-CHOP). Can subside in hours. Do not do tracheostomy.
  • Biopsy first before starting as HPE may change.
• Surgery - No role except for diagnostic biopsy
• RT & Chemotherapy - Mainstay of treatment.
  
  • Combination chemotherapy (Rituximab-CHOP) Cyclophosphamide, Doxorubicin, Oncovin (Vinblastine) & Prednisolone followed by RT to thyroid bed
  • Combination therapy alone without RT

Question 9

HPE of Thyroid Lymphoma

Answer 9

• Variable sized, rubbery / soft mass
• White cut surface with fish flesh appearance
• Necrosis could be found

Question 10

Prognosis

Answer 10

• Poor prognosis : Advanced stage > 10cm, Mediastinal involvement, diffuse B cell lymphoma subtype, perithyroidal soft tissue invasion, stage 2E or higher.
• Good prognostic factors: marginal zone lymphoma subtype or stage IE.
• Most recurrence in 1st 4 years.
• Overall survival 50 – 70%.

Question 11

Lymphadenopathy

Answer 11

Increased risk of lymphomawith:

• Exposure to pesticides
• Immune deficiencies
  
  • Common variably immune deficiency (lifetime risk 8%)
  • Wiscott-Aldrich syndrome
  • Severe combined immune deficiency
• Infections
  
  • HIV- Burkitt lymphoma, primary effusion lymphoma, DLBCL
  • EBV – Burkitt lymphoma
  • Herpes virus 8 - primary effusion lymphoma
  • Helicobacter pylori – MALT
  • Campylobacter jejuni – small bowel lymphoma
• Medications
  
  • Metotrexate – DLBCL, Hodgkins
  • Infliximab – T cell lymphoma

Question 12

Examination of Lymphadenopathy patient

Answer 12

Lymphomaiscanceroflymphatic cells, typically presenting as a solid tumour.

Signs and symptoms include: B Symptoms

• night sweats
• fever >380C (Pel–Ebstein feverswhich cyclically increase then decrease over an average period of one or two weeks.)
• weight loss (>10% of baseline within 6 months)
• fatigue
• palpable node

Diagnosis is bylymph node biopsy.

Other investigations include:

• CXR
• Staging CT
• Bloods – FBC, ESR, CRP, LDH, LFTs

Question 13

Notes on Hodgkin Lymphoma ( Oxford)

Answer 13

Question 14

Notes on Hodgkin Lymphoma ( Oxford) 2

Answer 14

Question 15

Notes on non Hodgkin Lymphoma ( Oxford)

Answer 15

Question 16

Notes on non Hodgkin Lymphoma ( Oxford) 2

Answer 16

Question 17

Summary of Lymphoma treatment

Answer 17

• Hodgkins lymphoma:
  
  • ABVD chemotherapy(=Adriamycin, bleomycin, vinblastine and dacarbazine
  • Radiotherapy
  • Exact treatment is based on a combination of the Ann Arbor staging and presence/absence of
    
    • 3 involved lymph node areas
    • high ESR
    • large mediastinal mass
    • extranodal disease
• High-grade Non-Hodgkins lymphoma
  
  • CHOP chemotherapy(= cyclophosphamide, doxorubicin, vincristine, prednisone)
  • rituxumab
• Low-grade Non-Hodgkins lymphoma
  
  • multiple options ranging from ‘watch and wait’ to chlorambucil to CHOP and rituximab.