Case Presentation LT4 pseudomalabsorption

Endocrine Grand Rounds
Case 07-11-98: A 41-year-old lady with “a history of papillary thyroid carcinoma and total thyroidectomy” presents with lack of response to levothyroxine treatment

Dr. L Mahmoudieh and Dr. M Takyar

Medical History and Physical Examination

Chief Complaint and HPI

• CC: “feeling weak and depressed”
  • Reason for Referral: Very high TSH levels not controlled with extreme doses of Levothyroxine.
• HPI: Our patient is a 41-year-old lady who was referred to be admitted to the Endocrine ward following detection of persistently very high TSH levels for the past two years despite receiving extreme doses of Levothyroxine.
  • Duration: Extreme weakness and feeling depressed for one month prior to admission.
  • Onset: She has been feeling like this for the past two years, but this latest episode of extreme symptoms started relatively abruptly last month.
  • Constant/Intermittent: The problem has been constant.
  • Precipitating factor: None elicited.
  • Alleviating factors: No specific factors identified.
  • Aggravating factors: Stressful life events.
  • Progression: Has not progressed significantly since it started.
  • Frequency: She has experienced such extreme symptoms twice during the past two years.
  • Associated symptoms: Malaise, headache, dizziness, blurred vision, occasional diarrhea following consumption of certain food items, lack of energy for talking, anxiety, lack of concentration.

HPI (Course of the illness)

• Painful neck swelling à isthmus nodule à scan: non-functioning
• Two nodules (8x5mm and 22x4 mm), hetero-echo with microcalcifications and some cystic changes. à FNA: many clusters of follicular epithelial cells with slightly enlarged nuclei, moderate anisonucleosis and rare intracellular inclusions (suggestive of neoplastic processes) à isthmectomy.
• Follow-up sonography à Lfet lobe: heterogenous, hypo-echoic nodule w/ calcifications/ reactive lymph nodes in the anterior jugular and left parotid regions. à total thyroidectomy à RAI treatment started (100 mCu)
  • Labs at discharge: TSH: 22.1, PTH: 48.9, Ca: 10.1, P: 4.2
• Pathology: PTC à Classic form, multifocal (left lobe + isthmus), margin-free (closest margin: 0.2cm), NO vascular, lymphatic, or perineural invasion.
  • Whole Body Scan: Negative
  • Labs: TSH: 1.2,Thyroglobulin: 1.2, Anti-Tg: negative, Anti-TPO: negative
  • Rx: RAI continued + Levothyroxine: (5x200mcg)+(2x150mcg)