Eruptive syringomas with associated calcinosis cutis—A case report and literature review of this association

Abstract

We report the case of a 9-year-old boy presenting with eruptive syringomas and macroscopic lesions of calcinosis cutis resembling subepidermal calcified nodules. Literature review revealed eruptive syringomas can be associated with calcinosis cutis with several different presentations. In this report, we review the five different presentations and associations of eruptive syringomas and calcinosis cutis, which to our knowledge has not been categorized before.

Case report

A 9-year-old male presented with a 2.5-year history of progressive monomorphic 2–3 mm tan brown papules over the trunk (Figure 1(a)), upper and lower extremities as well as indurated chalky white nodules over the knees (Figure 1(b)), and right thumb which appeared over the same period. The lesions were asymptomatic, and the child was otherwise healthy. The clinical differential diagnosis included eruptive syringomas, eruptive vellus hair cysts, papular sarcoidosis for the papules and idiopathic calcinosis cutis, dystrophic calcinosis cutis, subepidermal calcified nodules, and osteoma cutis for the white nodules.

Figure 1.

(a) Monomorphic tan-brown hyperpigmented papules over the trunk. (b) Indurated chalky white nodules over the knee.

The initial skin biopsy of a chest papule and a knee nodule was performed for routine histopathology. The papule showed focal dystrophic calcification with surrounding inflammation in the dermis (Figure 2(a)) and the nodule showed calcinosis cutis with possible perforation through the epidermis. The histologic findings of calcinosis in both specimens prompted a workup for causes of calcinosis cutis. Serum calcium, phosphate, parathyroid hormone (PTH), and CK were all normal and a myopathy antibody panel for dermatomyositis was negative.

Figure 2.

(a) Histology of a 4-mm punch biopsy from a chest papule showing a focus of calcification in the upper dermis (10× magnification). (b) Characteristic features of a syringoma (epithelial cuboidal cells in comma-shaped nests and cords) are demonstrated in a subsequent biopsy from a different chest papule (10× magnification).

Because the major clinical diagnosis for the papules was eruptive syringomas, deeper sections were requested from the initial tissue block of the chest papule and on a few sections, there was evidence of a syringoma. Also, to clarify the diagnosis, a second biopsy was later obtained from a different chest papule and showed epithelial cuboidal cells in comma-shaped nests and cords typical of a syringoma (Figure 2(b)) and no evidence of concomitant calcification.

The final diagnosis was eruptive syringomas with microscopic dystrophic calcification and macroscopic subepidermal nodule-like calcinosis cutis.

The present case was given a trial of 25% sodium thiosulfate in white petrolatum for a calcified nodule on the knee with minimal efficacy. Surgical excision of these lesions was considered and offered but declined because of the concern for scarring and poor cosmesis. No treatment was given for the eruptive syringomas although treatments considered included a trial of topical tretinoin, light electrodesiccation, or surgical excision.

Discussion

Eruptive syringomas, first described by Jacquet and Darier, are a variant of syringomas which are benign adnexal tumors of the eccrine sweat duct. ¹ This variant commonly develops in childhood to early adulthood and manifests in a generalized distribution largely involving the trunk and extremities. The lesions clinically manifest as asymptomatic firm yellow-brown to skin-colored papules.

A literature review was performed on the available cases of eruptive syringomas associated with calcinosis. The only associated syndrome in the reports was Down syndrome. In cases of eruptive syringomas with calcinosis cutis, serum calcium and phosphate are normal.

From our literature review, it appears that syringomas can be associated with calcinosis cutis in five different ways:

• (1) Syringomas can have microscopic calcification seen on pathology only and the calcification is therefore subclinical. ²

• (2) Rarer reports describe eruptive syringomas with lesions of macroscopic calcinosis cutis occurring at sites unrelated to the syringomas and these small macroscopic collections of calcinosis cutis are usually referred to as milia-like idiopathic calcinosis cutis (an entity usually seen on its own but also seen in patients with syringomas at distant sites).^3,4

• (3) There are reports of patients progressing from previous lesions of milia-like idiopathic calcinosis cutis (macroscopic calcification) to multiple eruptive syringomas). ⁵

• (4) There are reports of patients with clinical milia-like idiopathic calcinosis cutis showing calcinosis within a syringoma histologically on biopsies from the milia-like papules.^6,7

• (5) Larger macroscopic collections of calcinosis resembling subepidermal calcified nodules can be associated with syringomas at distant sites such as our case and there are two case reports in which biopsies from eyelid lesions showed syringomas in the dermis as well as subepidermal calcinosis with both cases reported as multiple subepidermal calcified nodules with syringomas.^8,9

It is unclear whether all these macroscopic calcium deposits are actually related to the syringomas or occur independently but when they coexist in the same location, it appears likely that the calcification is occurring within the syringomas due to dystrophic calcification.

A clinical variant of syringomas is milia-like syringomas which on histology may show syringomas with milia-like cysts or syringomas with microscopic calcium deposits or both. ¹⁰ A histologic variant is syringomas that have been reported to show transepidermal elimination of calcium. ¹¹

The present case and the published reports in the literature suggest that syringomas may occur in association with calcinosis in the context of healthy individuals as well as individuals with Down syndrome and when they do, this is likely not coincidental.

It has been hypothesized that calcium deposits are associated with syringomas as these areas are considered to be preferential sites for calcium deposits. Schepis and colleagues initially reported a case of an 11-year-old female with Down syndrome who presented with milia-like calcinosis cutis (without evidence of concomitant syringomas on biopsy but who did have periorbital syringomas diagnosed clinically but were not biopsy confirmed). ¹² Schepis published an updated report on the same patient at age 18 who developed an abrupt eruption of skin-colored papules on the face, neck, chest, and upper and lower limbs, and on biopsy from an arm lesion showed a syringoma but with associated many small dense globular structures consistent with calcium deposits seen in the lumen and periphery of the epithelial tubules of the syringoma. ² On electron microscopy, there was evidence of structural alterations with dense inclusions of calcification seen in the mitochondria and many lumina of the syringomas. Schepis et al. concluded that the syringeal structure plays a role in the pathogenesis of calcinosis cutis when calcinosis cutis is seen in conjunction with syringomas. ²