Faculty Bibliography

Subcutaneous fat necrosis (SCFN) is an inflammatory disorder of the adipose tissue that commonly presents in neonates as tender subcutaneous nodules on the trunk and extremities with hypercalcemia as a potential complication. We report the case of a 3-month-old female who presented with circular alopecia of the scalp and was found to have histopathologically confirmed SCFN. Recognition of SCFN as a cause for alopecia in young infants may allow prompt screening for hypercalcemia and reduce the risk for associated morbidity and mortality.

Nail unit pathology is indispensable to reach an accurate diagnosis of nail tumors as well as inflammatory disorders. This review article provides an update from the most recently published studies on the pathology and management of nail unit tumors and inflammatory disorders. Recent findings of nail clipping histopathology are described first, followed by discussing recent data on the diagnosis and surgical management of several types of nail unit tumors, ending with discussing the recent discoveries in selected nail unit inflammatory disorders.

A 6-year-old boy with severe very early-onset inflammatory bowel disease (VEO-IBD) was admitted for 1 week of high fevers, loose stools, joint pains, and myalgias. He subsequently developed a progressive, papular, and vesiculopustular eruption on his face with rapid spread to his trunk and extremities. Histopathology demonstrated dense dermal neutrophilic inflammation. Findings were consistent with bowel-associated dermatosis-arthritis syndrome (BADAS), which is rarely reported in children and requires further characterization.

The Shapiro xanthogranuloma is a histopathologic form of xanthogranuloma that shows closely packed monomorphous cells, which can extend into the subcutaneous fat; it usually lacks routine diagnostic features of xanthogranuloma. Herein we describe two cases of Shapiro xanthogranuloma occurring in a neonate and in an infant, which were initially thought to be hematologic malignancies. One patient's presentation as a "blueberry muffin baby" added to the diagnostic confusion. Pediatric dermatologists, dermatologists, and dermatopathologists need to be aware of the Shapiro xanthogranuloma and its clinicopathologic features to avoid misdiagnosis of a hematopoietic malignancy in neonates and infants.

Basal cell nevus syndrome (BCNS) is an autosomal dominant condition caused most often by a loss-of-function mutation in the Patched-1 (PTCH1) gene. It is characterized by the development of varied benign and malignant tumors, including numerous cutaneous basal cell carcinomas (BCCs). The PTCH1 gene is integral in hair follicle development and loss of function mutation may lead to BCCs with an infundibulocystic histopathology in BCNS patients. Few studies have described the histopathological features of BCCs in BCNS. The recognition of these histopathologic features by dermatologists, dermatopathologists, and others caring for children will allow earlier and more effective identification of BCNS. We performed a retrospective analysis of 25 BCCs in 11 patients aged 5 to 19 years with BCNS and evaluated the histopathologic features on hematoxylin-eosin-stained sections. Our study found that 80% of BCCs in BCNS patients occurred on the head and neck with 64% of the specimens demonstrating infundibulocystic differentiation. Infundibulocystic differentiation is a common finding in BCCs found in BCNS. The finding of cutaneous neoplasms consistent with BCC with infundibulocystic differentiation in children is common in pediatric patients with BCNS and can be considered to be an early marker of the disorder, prompting further clinical investigation.