The authors report the case of a 10-year-old girl with cellular neurothekeoma, a benign tumor that should be included in the differential diagnosis of paraorbital dermal lesions in the young, particularly women.
From Columbia University Medical Center, New York, New York.
The authors have no financial or proprietary interest in the materials presented herein.
Address correspondence to Martin L. Lieb, MD, Director, Orbit & Ophthalmic Plastic Surgery, Columbia University Medical Center, Harkness Eye Institute, 635 West 165th Street, New York, NY 10032. E-mail: email@example.com
Received: March 21, 2010
Accepted: April 05, 2010
Posted Online: July 22, 2010
A 10-year-old girl complained of a painless mass nasal to her medial canthus for approximately 1 year. The mass was approximately 8 mm in diameter, non-inflamed, rubbery in consistency, and mobile (Fig. 1).
Figure 1. An 8-mm Subcutaneous Mass Nasal to Medial Canthus in a 10-Year-Old Girl.
Due to the patient’s age, the appearance of the lesion, and its location in proximity to a bone suture, the clinical diagnosis of dermoid was made and its removal offered to the patient and family. During surgery, the lesion was found to be a subcutaneous demarcated nodule without lobularity and was excised in toto.
Histopathologic examination demonstrated a circumscribed, pseudo-encapsulated lesion surrounded by collagen bundles, composed of uniform spindle to stellate cells that were embedded in an abundant myxoid matrix (Fig. 2A). Clusters of epithelioid and multinucleated histiocytes were seen, some of which had characteristics of Touton-type giant cells and stained positive for CD68-PGM1 (Figs. 2B and 2C). A sparse inflammatory infiltrate was also identified, consisting predominantly of lymphocytes, but no eosinophils were identified. An MIB-1–Ki67 stain was performed and 30 mitoses per 10 high-power fields were detected. The lesion did not stain for CD34 (characteristic for the myxoid type of dermatofibroma protuberans), CD1a (Langerhans’ histiocytosis), S-100, or EMA (benign nerve sheath tumors, such as dermal nerve sheath myxoma, sometimes called “myxoid neurothekeoma,” and Spitz nevus). Immunohistochemical staining for alpha-smooth muscle actin, muscle-specific actin, and desmin were all negative (not shown). Sparse, thin-walled vascular channels supplied the lesion, as highlighted by CD34 staining (not shown).
Figure 2. (A) Low-Power Photomicrograph of the Hematoxylin–Eosin Stained Lesion Demonstrates a Circumscribed, Pseudo-Encapsulated Lesion Surrounded by Collagen Bundles, Composed of Uniform Spindle to Stellate Cells Embedded in Abundant Myxoid Matrix (original Magnification ×100). (B) Medium-Power Photomicrograph of CD68-Immunostained Tumor Cells (original Magnification ×200). (C) High-Power Photomicrograph of CD68-Immunostained Lesional Cells and Touton-Type Giant Cell (original Magnification ×400).
These findings are in keeping with a diagnosis of cellular neurothekeoma,1 which is a benign cutaneous tumor of controversial histiogenesis.2 It is usually found on the head, neck, or lower extremities of young females (average age = 25 years) with a mean tumor size of 1 cm, rarely exceeding 2 cm. Usually they are poorly marginated and consist of micronodular or lobulated tumors, with spindle and epithelioid cells within variable amounts of myxoid stroma. It is probably unrelated to dermal nerve sheath myxoma or “myxoid neurothekeoma” because it lacks immunoreactivity for neural markers.3 Neurothekeoma might therefore be a misnomer, given its questionable neural origin. Even if the lesion is not excised with clear margins, it rarely recurs.
In addition to dermoid, the differential diagnosis of paraorbital dermal lesions in the young includes Spitz nevus, which shows similarly spindled cells but is typically darker clinically and accordingly positive for S100 and other melanocytic markers. True nerve sheath myxoma presents later in life and only rarely involves the head and neck. Although they display similar cell morphology, they are S100 positive, unlike the tumor presented here. Superficial angiomyxoma is highly myxoid and usually CD34+ and negative or weakly reactive for S100. The recurrence rate is 30% to 40%, significantly higher than with neurothekeoma. Cellular neurothekeomata are benign tumors that should be included in the differential diagnosis of paraorbital dermal lesions in the young, particularly females.
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