Osteoma cutis is a benign uncommon tumor characterized by the presence of bone tissue in dermis or hypodermis. It is classified as primary when the bone tissue originates from the skin without a preexisting lesion and secondary when there has been a previous inflammatory, traumatic, cicatricial, or neoplastic process [ 1 ] . We report a case of primary plaque osteoma cutis.
A 27-year-old woman presented with a 9-year history of slowly enlarging, hard lesions on her scalp, forehead, and nose, which created 2 irregular plaques that were painful on palpation, both with erythema in their periphery. The plaques measured approximately 1 to 5 mm in diameter ( Figure 1 ).
Figure 1 .
Clinical features: Plaque-like tumor on the patient’s scalp, forehead, and nose. [Copyright: ©2019 Romero Navarrete et al.]
Dermoscopy showed concentric white and yellowish structures with an erythematous border area ( Figure 2 ).
Figure 2 .
Dermoscopic image: Well-limited, concentric structures in linear arrangement with an erythematous and nacreous pink border. [Copyright: ©2019 Romero Navarrete et al.]
At age 18 the patient noted 2 small scalp lesions, hard and painful, that increased in number and size over the years. There was no personal or family history relevant to her condition. Her otorhinolaryngologist reported a slight visible central nasal pyramid with slight irregularities.
Histopathology showed a stratum corneum with basket-weave pattern, irregular acanthosis and hyperpigmentation of basal layer, superficial, and middle dermis with dilated blood vessels, atrophic hair follicles, no alteration of sweat glands, and a mild perivascular inflammatory lymphocytic infiltrate. The subcutaneous cellular tissue contained a cluster of mature bone tissue with blood vessels and connective tissue. Bone trabeculae had osteocytes ( Figure 3 ).
Figure 3 .
Histopathology: Clusters of mature bone and bone trabeculae with osteocytes, blood vessels, and connective tissue (hematoxylin and eosin, 40×). [Copyright: ©2019 Romero Navarrete et al.]
The simple lateral skull and contrast inversion radiograph showed punctiform images in the skin and subcutaneous cellular tissue of the frontal region and nasal pyramid ( Figure 4A,B ).
Figure 4 .
X-ray: Forehead and nasal pyramid with punctiform lesions in the skin and subcutaneous cellular tissue. [Copyright: ©2019 Romero Navarrete et al.]
Laboratory values such as thyroid and lipid profile, blood chemistry, and serum calcium and phosphorus levels were within normal ranges.
Osteoma cutis, first described by Wilkens in 1858, is a benign tumor of bone in the dermis or hypodermis [ 1 ] . It is classified as primary or secondary. The primary forms represent 14%–15% of all cutaneous ossifications and can be present in association with Albright hereditary osteodystrophy, progressive ossification, fibrodysplasia, or progressive osseous heteroplasia, as well as isolated, osteoma, generalized or multiple facial miliaria and plaques; and occasionally they present with transepidermal bone elimination. Secondary forms have a previous trauma, infection, inflammation, or neoplasia [ 1 , 2 ] .
The term osteoma cutis in plaque was given by Worret and Burgdorf in 1978 [ 3 ] . This entity can be congenital or be present in the first year of life. It is associated with neither metabolic calcium nor phosphorus alteration, nor with previous trauma or infections. It is composed of one or more plaques of bone tissue.
Osteoma cutis is also used to name similar lesions that are acquired after the first year of life [ 1 ] . Its pathogenesis is unknown, and it has been related to the abnormal migration of osteoblast to the skin or a metaplasia of fibroblast to osteoblasts.
The case described in this report corresponds to a primary plaque osteoma cutis in an adult woman, with 9 years of evolution without reported abnormality in calcium, phosphorus, or any previous trauma or infection. Histopathology showed mature bone cluster in the subcutaneous cellular tissue.
We searched PubMed using the key words osteoma cutis, primary osteoma cutis, plaque-like osteoma cutis, acquired plate-like, plate-like osteoma cutis , and primary osteoma cutis . We found 20 publications concerning primary osteoma cutis [ 1 , 2 ] , and with our report there are 21 ( Table 1 ).
Publications Describing Plaque-Like Osteoma Cutis: 1985–2017
Previous reports found 57% of osteoma cutis occurring in males and 43% in females, with an age range from 10 to 77 years, median 37.8.
Previously reported treatments include surgery in 40% of cases [ 1 , 2 ] . One patient was treated with 0.025% retinoic acid [ 2 ] . Two cases with follow-up at 6 months and 2 years reported no new lesions or recurrences [ 1 , 2 ] .
We report the first primary plaque-like osteoma cutis case in Mexico with histopathological correlation. This is an uncommon entity and our case is the second one that includes dermoscopic findings.
- Plaque-like osteoma cutis with transepidermal elimination Haro R, Revelles JM, Angulo J, et al. J Cutan Pathol.2009;36(5):591-593.
- Primary isolated osteoma cutis on the face Moreira AG, Mastrangelo MFE, Carvalho QD, Cuzzi T, Canedo de MT, Raso BP. Dermatol Online J.2017;23(4):1-4.
- Congenital plaque-like osteoma of the skin in an infant [in German] Worret WI, Burgdorf W. Hautzart.1978;29(1):590-596.