# Trisomy 18 with widespread calcinosis cutis

## TL;DR

A 6-year-old girl with trisomy 18 developed calcinosis cutis, a rare skin condition involving calcium deposits, which is the first reported case in a pediatric trisomy 18 patient.

## Contribution

This is the first documented case of calcinosis cutis in a long-term pediatric trisomy 18 survivor.

## Key findings

- The patient exhibited subcutaneous nodules with calcium deposition confirmed by biopsy and imaging.
- Metabolic and nutritional causes for calcinosis cutis were ruled out in the patient.
- The case is classified as dystrophic or idiopathic calcinosis cutis.

## Abstract

Trisomy 18 is the second most common autosomal trisomy, associated with high mortality, with only 5–10% of affected individuals surviving beyond the first year of life. Consequently, comorbidities in long-term survivors are rarely reported. We describe the case of a 6-year-old East Asian girl with trisomy 18 who presented with calcinosis cutis. The patient initially developed a firm, non-tender subcutaneous nodule on the left wrist, which later spread to the forearm and upper arm. Physical examination and imaging revealed extensive subcutaneous nodules in other extremities. High-frequency ultrasonography showed hypoechogenic masses with posterior acoustic shadows, while skin biopsy revealed fat necrosis and calcium deposition. No significant abnormalities were detected in the levels of calcium, phosphorus, parathyroid hormone or vitamin D. Based on laboratory findings and the patient’s medical history, metabolic, nutritional, inflammatory and iatrogenic causes of calcinosis cutis were unlikely. Consequently, the condition was classified as either dystrophic or idiopathic calcinosis cutis. The patient was managed as an outpatient without specific treatment. This report discusses the mechanisms of calcinosis cutis and the reasons for the limited research on its association with trisomy 18. To our knowledge, this is the first report describing calcinosis cutis as a concomitant condition in a paediatric patient with trisomy 18, and it is anticipated that increased awareness of this disease may lead to a rise in reported cases in the future.

Rapid advancements in neonatal care have resulted in a long-term survival in cases of trisomy 18, and few reports of dermatological comorbidities exist. Organ calcification during the fetal stage is known to be associated with chromosomal abnormalities. We describe the case of a 6-year-old East Asian girl with trisomy 18 who presented with calcinosis cutis.