We report 2 cases of a foreign body reaction to Radiesse, a semipermanent soft-tissue filler consisting of 30% calcium hydroxylapatite microspheres and 70% carboxymethyl cellulose gel carrier. In one case, injection of this filler provoked a nodule on the columella, which was discovered during rhinoplasty. In the second case, the reaction was revealed during histopathologic examination of the deep section of a surgically removed basal-cell carcinoma. Histopathology showed a foreign body reaction with numerous giant cells and histiocytes, some plasma cells, and lymphocytes. Within this inflammatory reaction, a nonpolarizing exogenous material was identified consisting of numerous, round, uniformly sized, yellowish, extracellular deposits with a crackled appearance. Although many authors claim that Radiesse does not induce any foreign body reactions, we found a number of similar histopathologic pictures in studies describing animal or human auricular area test sites or even in reports of lip nodules, which are a well-known adverse effect after injection of this filler into this site. The histopathologic appearance of Radiesse is particularly distinctive and easily recognizable by dermatologists and dermatopathologists.

Panniculitides form a heterogenous group of inflammatory diseases that involve the subcutaneous adipose tissue. These disorders are rare in children and have many aetiologies. As in adults, the panniculitis can be the primary process in a systemic disorder or a secondary process that results from infection, trauma or exposure to medication. Some types of panniculitis are seen more commonly or exclusively in children, and several new entities have been described in recent years. Most types of panniculitis have the same clinical presentation (regardless of the aetiology), with tender, erythematous subcutaneous nodules. Although the patient’s age and the lesion site provide information, a histopathological assessment is sometimes required for a definitive diagnosis and classification of the disorder. In children, most panniculitides are lobular. At present, autoimmune inflammatory diseases and primary immunodeficiencies have been better characterised; panniculitis can be the presenting symptom in some of these settings. Unexplained panniculitis in a young child should prompt a detailed screen for monogenic immune disorders because the latter usually manifest themselves early in life. Here, we review forms of panniculitis that occur primarily in children, with a focus on newly described entities.

Tibial lymphoplasmacytic plaque (TLP) is a recently recognized clinicopathological entity affecting children and is characterized by a linear, reddish brown plaque on the leg with a dense dermal lymphoplasmacytic infiltrate. No effective treatments are available for this lesion of unknown etiology and its course is chronic. We report a new case in which, for the first time, a causative factor (insect bite) is strongly suspected. The clinical and pathological features of TLP may be misleading for the uninformed dermatologist or pathologist. Therefore, we would like to draw attention to this very distinctive clinicopathological presentation in order to help them recognize it easily and prevent it from being misdiagnosed as an infectious disease or, above all, a cutaneous lymphoma. We will discuss the relationship between TLP and linear acral pseudolymphomatous angiokeratoma of children, a variant of pseudolymphoma localized on acral sites in children which may share some of TLP’s histopathological features.

A new resorbable filler, Novabel, became commercially available in January 2010 in France. A 52-year-old general practitioner injected 0.1 cm3 of a 1 cm3 alginate solution (Novabel) into the deep dermis of her left arm to test it before using it on her patients. Ten days later, she observed a small pink nodule at the injection site forming secondary a bluish papule. A biopsy was performed 2 months after the injection. Histopathology showed a granulomatous reaction involving the deep dermis and the subcutaneous fat. The inflammatory reaction surrounded a nonpolarizing exogenous material consisting of slightly bluish deposits of variable size and shape, some of which were well delineated, others with a blurred or spiky perimeter, frequently showing retraction in a clear vacuole. The papule regressed, resolving completely 5 months after the injection. Novabel is a totally new type of aesthetic injectable resorbable filler consisting of a purified polysaccharide, alginate, which is extracted from crusted brown algae. No side effects have been reported to date and we describe here a first granulomatous reaction after filler injection which has a distinctive appearance in keeping with the histopathological findings.