Unknown: A man with infiltrated and indurated plaque on the forehead
J Aneiros-Fernandez MD1, H Husein-ElAhmed MD2, J Orgaz-Molina MD2, F O'Valle Ravassa MD PhD1, S Arias-Santiago MD2
Dermatology Online Journal 16 (6): 12

1. Department of Pathology, University Hospital, Granada, Spain. janeirosf@hotmail.com
2. Department of Dermatology, University Hospital, Granada, Spain


Abstract

Osteoma cutis, a rare benign condition characterized by the presence of osseous nodules are composed of lamellar bone with osteocytes in the center and osteoclasts in the external area, in the reticular layer of the skin. Osteoma cutis can be either primary, arising de novo in healthy skin, or secondary, developing in association with pre-existing neoplastic or inflammatory skin lesions. We present a 25-year-old man with plaque-like osteoma cutis.



Answer: Plaque-like osteoma cutis


Figure 1 Figure 2
Figure 1. Exophytic lesion of the scalp

Figure 2. Well-circumscribed nodules of mature lamellar bone surrounded by connective tissue and containing marrow spaces can be observed (H&E, panoramic)

Figure 3
Figure 3. Higher magnification reveals transepidermal elimination (H&E, x100)

A 25-year-old man presented with multiple nodules involving the left forehead. The lesions had been present for 1½ years and had grown progressively. Clinical examination revealed a 2 cm infiltrated and indurated asymptomatic plaque on the forehead (Figure 1). The rest of his cutaneous exam was normal. The patient denied any history of local trauma or acne vulgaris and the previous endocrine evaluation did not show any hormone alterations. Histologic sections are shown in Figures 2 and 3.


Microscopic findings and clinical course

Histological sections of skin showed small spicules to large masses of mature bone in the dermis or extending into the subcutaneous tissue. Spicules of bone may enclose areas of mature fat. Because bone located in the superficial dermis causes an irritant reaction, the material may gradually be brought toward the surface and finally eliminated. This is found in islolated primary osteoma cutis with transepidermal elimination. In our patient, the plaque was treated with surgical excision without any evidence of recurrence after 1 year of follow-up.


Discussion

Osteoma cutis, a rare benign dermatosis is characterized by the presence of osseous nodules in the skin, which are composed of lamellar bone with osteocytes in the center and osteoclasts in the external area, in the reticular layer of the skin. Three theories have been suggested for the pathogenesis of this lesion; 1. Mesenchymal tissue may differentiate into bone in the presence of the tissue injury; 2. Fibroblasts may differentiate into osteoblastic cells; and 3. Displaced pluripotential cells may suffer a metaplastic transformation in the presence of stimulating factors, such as trauma or treatment [1].

Osteoma cutis can be either primary, arising de novo in healthy skin, or secondary, developing in association with pre-existing neoplastic or inflammatory skin lesions (Table 1) [2-10].

Plaque-like osteoma cutis was described by Worret in 1978 and, by definition, is not associated with metabolic alterations, traumatic or inflammatory antecedents, or congenital development through the first year of life) [11].

Some cases of osteoma cutis exhibit the phenomenon of transepidermal elimination [12] similar to granuloma annulare, elastolisis perforans serpiginosa, perforating folliculitis, and perforating pilomatricoma.

Treatment of osteoma cutis generally consists of removal by excision or laser resurfacing. Treatment with the Er:YAG laser may result in less hypopigmentation and scarring than with the carbon dioxide laser. Other reported treatments with unproven efficacy include topical application of tretinoin to provoke transepidermal elimination, oral bisphosphonates,, and the needle microincision-extirpation technique [13, 14].

References

1. Samaniego-González E, Crespo-Erchiga A, Gómez-Moyano E, Boz-González JD, Sanz-Trelles A. Perforans multiple osteoma cutis on the leg in a young woman. J Cutan Pathol. 2009;36:497-8. [PubMed]

2. Subramanyam L, Gowrishankar K, Shivbalan S, Balachandran A. Fibrodysplasia ossificans progressiva. Indian J Pediatr. 2004;71(6):563-4. [PubMed]

3. Klaassens M, Blom EW, Schrander JJ, Ris-Stalpers C, Nieuwenhuijzen Kruseman AC, van Steensel MA, Schrander-Stumpel CT. Unique skin changes in a case of Albright hereditary osteodystrophy caused by a rare GNAS1 mutation. Br J Dermatol. 2009: 26. [PubMed]

4. Santiago F, Vieira R, Cordeiro M, Tellechea O, Figueiredo A. Unilateral progressive osseous heteroplasia. Eur J Dermatol. 2009;19(3):214-5. [PubMed]

5. Juhn E, Khachemoune A. Gardner syndrome: skin manifestations, differentialdiagnosis and management. Am J Clin Dermatol. 2010;11(2):117-22. [PubMed]

6. Shoji T, Burlage AM, Bhawan J. Basal cell carcinoma with massive ossification. Am J Dermatopathol. 1999;21(1):34-6. [PubMed]

7. Thielen AM, Stucki L, Braun RP, Masouyé I, Germanier L, Harms M, Salomon D, Borradori L. Multiple cutaneous osteomas of the face associated with chronicinflammatory acne. J Eur Acad Dermatol Venereol. 2006;20(3):321-6. [PubMed]

8. Julian CG, Bowers PW. Osteoma cutis in a lesion of solitary morphoea profunda. Clin Exp Dermatol. 2003;28(6):673-4. [PubMed]

9. Monteiro MR, Koblenzer CS. Multiple osteoma cutis lesions associated with acne. Int J Dermatol. 2000;39(7):553-4. [PubMed]

10. Ahn SK, Won JH, Choi EH, Kim SC, Lee SH. Perforating plate-like osteoma cutis in a man with solitary morphoea profunda. Br J Dermatol. 1996;134(5):949-52. [PubMed]

11. Worret WI, Burgdorf W. [Congenital, plaque-like osteoma of the skin in an infant]. Hautarzt. 1978;29(11):590-6. [PubMed]

12. Haro R, Revelles JM, Angulo J, Fariña Mdel C, Martín L, Requena L. Plaque-like osteoma cutis with transepidermal elimination. J Cutan Pathol. 2009;36(5):591-3. [PubMed]

13. Cohen AD, Chetov T, Cagnano E, Naimer S, Vardy DA. Treatment of multiple miliary osteoma cutis of the face with local application of tretinoin (all-trans-retinoic acid): a case report and review of the literature. J Dermatolog Treat. 2001;12(3):171-3. [PubMed]

14. Ochsendorf FR, Kaufmann R. Erbium: YAG laser ablation of osteoma cutis: modifications of the approach. Arch Dermatol. 1999;135(11):1416. [PubMed]

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