Occult Metastatic Papillary Thyroid Cancer in an Adolescent

Background/Objective

Occult papillary thyroid carcinoma (PTC) is PTC with metastasis but without identification of primary thyroid cancer on preoperative ultrasonography. Published reports on occult PTC in children are limited.

Case Report

We describe a 16-year-old female with occult PTC who initially presented with a painless left sided cystic neck mass. Diffuse sclerosing variant papillary thyroid cancer was found in the resected neck mass and thyroid ultrasound did not show any nodules or features of carcinoma. After total thyroidectomy, pathological examination of the thyroid revealed papillary thyroid microcarcinoma.

Discussion

We describe a rare case of occult diffuse sclerosing variant papillary thyroid cancer presenting as a cystic neck mass mimicking a second branchial cleft cyst in an adolescent patient. When metastatic PTC is found without evidence of nodule on thyroid imaging, occult PTC of the thyroid is the likely diagnosis.

Conclusion

Total thyroidectomy ± neck dissection followed by TSH suppression and radioactive iodine therapy remains the appropriate diagnostic and therapeutic interventions.

Persistent hypercalcemia mimicking hypophosphatasia after discontinuation of a ketogenic diet: a case report

OBJECTIVES

Hypercalcemia has been reported as an uncommon complication of the ketogenic diet (KD). Here we present a toddler whose hypercalcemia persisted for 2 months after stopping the KD.

CASE PRESENTATION

A 2 year 11-month-old child with global developmental delay, infantile spasms, neuromuscular weakness with limited mobility, tracheostomy and ventilator dependence, and oropharyngeal dysphagia with G-tube dependence presented with hypercalcemia in the setting of recurrent vomiting. At presentation, the patient was adherent to a KD and taking topiramate since infancy for intractable seizures. His laboratory parameters at presentation showed hypercalcemia (11.9 mg/dL), hypercalciuria, acute renal failure, low alkaline phosphatase (76 IU/L [110-302 IU/L]), parathyroid hormone (PTH) <6 pg/mL (18-80 pg/mL), normal thyroid function, cortisol and vitamin D level. The patient's hypercalcemia persisted post-discontinuation of the KD and topiramate. PTH-related protein was mildly elevated at 15.3 pmol/L. Follow-up laboratory and imaging studies ruled out malignancy. He was managed with calcitonin 4 u/kg/dose Q12H × 1 day and 8 u/kg/dose Q8H × 1 day, hydration and low-calcium formula. Post-discontinuation of the KD, normalization of alkaline phosphatase levels preceded the normalization of calcium on day 55 and PTH on day 85.

CONCLUSIONS

Hypercalcemia may persist for an extended period after weaning from a KD; lab parameters may mimic that of hypophosphatasia as previously described in the literature. Normalization of alkaline phosphatase, a marker of bone turnover, indicates recovery from the adynamic state induced by the KD and typically precedes the normalization of calcium and PTH.

Infantile presentation of 3q26.33-3q27.2 deletion syndrome

A very rare syndrome, 3q26.33-3q27. 2 microdeletion, has only been described in seven case reports previously, all of which highlight genotypic and phenotypic variations of the presentations identified in school-aged and adolescent children. The patients in these cases had varying sized deletions but overlapping manifestations. Hallmarks of the deletion include intrauterine growth restriction (IUGR), failure to thrive/feeding difficulty, dysmorphic facial features, delayed dentition, pes planus, intellectual/developmental delay, hypotonia and recurrent infections. This case report aims to document the presentation of 3q26.33-3q27.2 microdeletion in infancy for the first time in the literature. Through early recognition of specific genetic causes for IUGR, such as this microdeletion, we can better anticipate and prepare for the patient's needs in the neonatal period and in the future.