Subacute Thyroiditis / De Quervain’s Thyroiditis (Part II)


  • Clinical Manifestations:
    • The clinical manifestations:
      • May be preceded by an upper respiratory tract infection, or a prodromal phase of:
        • General malaise
        • Generalized myalgia
        • Pharyngitis
        • Low-grade fevers
      • Pain or swelling in the thyroid region develops later:
        • Accompanied by higher fevers
      • Up to 50% of patients have symptoms of thyrotoxicosis
      • Pain may be moderate or severe
      • Rarely symptoms are entirely lacking
      • Similarly:
        • Tenderness may be moderate or severe (or even exquisite):
          • Or conversely, may rarely be lacking
      • One of the lobes may be involved initially and later spread to the opposite lobe:
        • “Creeping thyroiditis”
      • Both lobes may be involved from the outset
      • The systemic reaction:
        • May be minimal or severe
          • Fevers may reach 40°C
      • Rarely, subacute thyroiditis may present as:
        • A non-tender solitary nodule:
          • In these cases, the diagnosis has been made after fine-needle aspiration biopsy:
            • Atypical presentations are often misdiagnosed as papillary cancer
      • Patients can generally localize the pain to the thyroid region over one or both lobes
      • They may refer to their symptoms as a “sore throat,”:
        • But upon specific questioning it becomes apparent that pain is in the neck, not within the pharynx.
      • Typically, pain radiates from the thyroid region:
        • Up to the angle of the jaw or to the ear on the affected side(s).
        • The pain may also radiate to the anterior chest or may be centered over the thyroid only
        • Moving the head, swallowing, or coughing may aggravate pain
      • Although an occasional patient may have no systemic symptoms, most complain of:
        • Myalgia
        • Fatigue
        • Fevers
        • Malaise:
          • Can be extreme and can be associated with arthralgias


  • On physical exam:
    • Most patients appear uncomfortable and flushed on inspection:
      • With variable elevations in temperature
    • Palpation usually reveals:
      • An exquisitely tender, hard, ill-defined nodular thyroid:
        • The tender region may encompass an entire lobe and mild tenderness may be present in the contralateral lobe
    • The overlying skin is occasionally warm and erythematous
    • Cervical lymphadenopathy is rarely present
    • Although the majority of patients are only mildly to moderately ill:
      • Subacute thyroiditis may have a dramatic presentation:
        • With marked fever (greater than 40°C)
        • Severe thyrotoxicosis
        • Obstructive symptoms:
          • Resulting from pronounced thyroid inflammation and edema
    • During the active / painful phase of subacute thyroiditis:
      • The erythrocyte sedimentation rate is:
        • Markedly elevated:
          • In fact, a normal erythrocyte sedimentation rate essentially rules out subacute thyroiditis as a tenable diagnosis
      • The white blood count is normal to mildly increased
      • There is often a normochromic, normocytic anemia
      • During the inflammatory phase there are increases in:
        • Serum ferritin
        • Soluble intercellular adhesion molecule-1
        • Selectin
        • Interleukin-6 levels
        • C-reactive protein
        • Alkaline phosphatase and other hepatic enzymes may be elevated in the early phase:
          • It has been suggested that subacute thyroiditis may actually represent a multi-system disease also affecting the thyroid
      • In the thyrotoxic phase:
        • The serum T4 concentration is disproportionately elevated relative to the serum T3 concentration:
          • Reflecting the intra-thyroidal T4:T3 ratio
          • In addition:
            • The acute illness decreases the peripheral deiodination of T4 to T3:
              • Resulting in lower serum T3 concentrations than expected.
        • Serum TSH concentrations are low to undetectable
        • It is important to note in subacute thyroiditis:
          • Antibodies directed against thyroglobulin and thyroid peroxidase:
            • Are either absent or present in low titer:
              • These develop several weeks after disease onset and tend to disappear thereafter
    • The radioactive iodine uptake:
      • During the thyrotoxic phase is:
        • Low:
          • Most often less than 2% at 24 hours:
            • As with the erythrocyte sedimentation rate:
              • A normal radioactive iodine uptake essentially rules out subacute thyroiditis as a tenable diagnosis
      • Ultrasound:
        • May show generalized, multiple, or single regions of hypoechogenicity


  • Pathology:
    • The primary events in the pathology of subacute thyroiditis are:
      • Destruction of the follicular epithelium
      • Loss of follicular integrity:
        • However the histopathologic changes:
          • Are distinct from those found with Hashimoto’s thyroiditis
    • The lesions are:
      • Patchy in distribution and are off:
        • Varying stages of development
      • With infiltration of mononuclear cells in affected regions
      • Partial or complete loss of colloid
      • Fragmentation and duplication of the basement membrane
      • Histiocytes congregate around masses of colloid:
        • Both within the follicles and in the interstitial tissues:
          • Producing giant cells:
            • Often these giant cells consist of:
              • Masses of colloid surrounded by large numbers of individual histiocytes:
                • So they more accurately should be termed pseudo-giant cells
      • The term granulomatous thyroiditis:
        • A synonym for subacute thyroiditis:
          • Should likewise be changed to pseudo-granulomatous thyroiditis:
            • However, true giant cells and granulomas do appear in this disease as well
      • During recovery:
        • The inflammation recedes and there is a variable amount of fibrosis and fibrotic band formation
        • In addition:
          • Follicular regeneration occurs:
            • Without caseation, hemorrhage, or calcification
        • Recovery is generally complete:
          • Only in the rare instance:
            • Is there complete destruction of the thyroid parenchyma that leads to:
              • Permanent hypothyroidism





















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