Congenital solitary osseous choristoma of the left lateral canthus: a case report.

BACKGROUND: An ocular osseous choristoma is a growth of mature, compact bone in the ocular or periocular soft tissue, and it is the rarest form of ocular choristoma, accounting for only 1.7% of all epibulbar choristomas. CASE PRESENTATION: Herein we present the case of a 20-month-old girl who was referred to the oculoplasty clinic with a progressively growing mass in the left lateral canthus. It had been present since birth without ocular involvement. Upon examination the mass was firm with a smooth surface, measured 9 × 6 × 3 mm, and exhibited no episcleral attachment or ocular involvement. An excisional biopsy was performed, and the histopathological findings were consistent with osseous choristoma of the left lateral canthus. CONCLUSIONS: This report highlights the importance of considering osseous choristoma in the differential diagnosis of eyelid lesions, particularly those that have been present since birth. It also emphasizes the need for further studies investigating associations between osseous choristomas and ocular canthi.

Miliary osteoma cutis in a climbing mantella frog (Mantella laevigata).

A climbing mantella frog (Mantella laevigata) was presented with nodular thickened skin. Histological examination revealed dermal nodules composed of differentiated bone consistent with miliary osteoma cutis, a non-neoplastic condition where bone is abnormally deposited within the skin. This is the first report of idiopathic osteoma cutis in an amphibian.

[Benign skin neoplasms in children]. / Gutartige Hauttumoren bei Kindern.

There are many different types of skin neoplasms in children and most are benign. Dermatologists should be able to differentiate between the various types of benign skin neoplasms and be able to recommend optimal treatment to concerned patients. Surgical removal of benign skin neoplasms is often the only treatment option. The aim of this paper is to provide a general overview of epidermal lesions (e.g., inflammatory linear verrucous epidermal nevus [ILVEN], nevus sebaceous), tumors of the epidermal appendages (e.g. pilomatrixoma), cutaneous neoplasms (e.g. angiofibroma), fibromatoses (e.g., knuckle pads), tumors comprised of fat, muscle, or bone tissue (e.g., osteoma cutis, subungual exostosis), epidermal cysts and pseudocysts, and pathologic fibrosis reactions after dermal injury (keloid). Scientific data are scarce and only in the last decade has it been possible to perform histopathological examinations and genetic studies together with detailed phenotyping to gain new understanding of the pathogenetic mechanisms.

Multiple miliary osteoma cutis, renal failure and secondary hyperparathyroidism in a geriatric patient.

INTRODUCTION: Miliary osteoma cutis (MOC) is a cutaneous disorder that develops in response to an ill-defined process or following acne vulgaris. Most cases present incidentally as small radiographic aggregations of normal bone within the cheeks. Infrequently, MOC has been reported with systemic disease, including renal failure. CASE PRESENTATION: An 82-year-old man presented with renal failure and secondary hyperparathyroidism. Intraoral radiographs displayed bilateral radiopacities. This is the first documented case of MOC synchronous with renal failure and secondary hyperparathyroidism in a geriatric patient. CONCLUSIONS: Patients with MOC and manifestations associated with nephropathy should undergo a comprehensive medical work-up and laboratory studies. Timely recognition of incidental radiographic findings may improve clinical outcomes.

Neonatal osteoma cutis due to a mutation in GNAS.

We describe a 4-week-old baby boy who presented with white firm cutaneous nodules and failure to thrive. He did not have dysmorphic features, and laboratory tests including serum calcium, phosphorous, thyroid function, and parathyroid hormone level were within normal ranges. Whole exome sequencing revealed an inactivating mutation in GNAS that was previously described as causing pseudohypoparathyroidism.

Rothmund-Thomson syndrome and osteoma cutis in a patient previously diagnosed as COPS syndrome.

We present a patient with poikiloderma, severe osteoporosis and a mild intellectual disability. At the age of 9 years, this patient was proposed to suffer from a novel disease entity designated as calcinosis cutis, osteoma cutis, poikiloderma and skeletal abnormalities (COPS) syndrome. At the age of 35, he was diagnosed with Hodgkin's lymphoma. Recently, biallelic pathogenic variants in the RECQL4 gene were detected (c.1048_1049delAG and c.1391-1G>A), confirming a diagnosis of Rothmund-Thomson syndrome (RTS). In the brother of this patient, who had a milder phenotype, a similar diagnosis was made. CONCLUSION: We conclude that COPS syndrome never existed as a separate syndrome entity. Instead, osteoma cutis may be regarded as a novel feature of RTS, whereas mild intellectual disability and lymphoma may be underreported parts of the phenotype. What is new: • Osteoma cutis was not a known feature in Rothmund-Thomson patients. • Intellectual disability may be considered a rare feature in RTS; more study is needed. What is known: • RTS is a well-described syndrome caused by mutations in the RECQL4 gene. • Patients with RTS frequently show chromosomal abnormalities like, e.g. mosaic trisomy 8.

Primary isolated osteoma cutis causing eyelid deformation and strabismus in a dog.

Osteoma cutis describes bone formation in skin and is well documented in the medical literature, but veterinary reports are few. We report a single case of a juvenile samoyed that was referred for assessment of a superior eyelid anomaly. Exploratory surgery and histopathology revealed the presence of mature, lamellar bone within the superior eyelid. The histologic appearance was consistent with primary osteoma cutis. The presence of the ossification within the deep dermis of the eyelid was associated with an abnormal conformation causing trichiasis, keratitis and dorsal strabismus. Identification of the osseous lesion during surgery and its removal was curative with no recurrence of disease during the 32 month follow-up period.

Extramedullary acute leukemia developing in a pre-existing osteoma cutis.

Primary osteoma cutis (cutaneous ossification) is an uncommon disease in which there is bone formation within the skin in the absence of a demonstrable pre-existing condition. Osteoma cutis is a chronic and benign condition. We report a case of a 45-year-old man who developed extramedullary acute leukemia with a myeloid immunophenotype (myeloid sarcoma) with its initial presentation within an isolated pre-existing osteoma cutis in the post-auricular scalp without evidence of systemic acute leukemia or chronic myeloid stem cell disorders. The tumor was surgically excised without complications. Four months later, acute leukemia recurred in the contralateral posterior mandible and showed an immunophenotype consistent with acute lymphoblastic leukemia/lymphoma. The patient now has been treated by standard protocols for acute leukemia. The diagnosis of an extramedullary acute leukemia is challenging because of its inconsistent clinical and histopathologic presentations. Extramedullary acute leukemia developing in a pre-existing osteoma cutis is very unusual and has not been previously reported in the literature.

Medulloblastoma in a child with osteoma cutis - a rare association due to loss of GNAS expression.

OBJECTIVES: Inactivating GNAS mutations result in varied phenotypes depending on parental origin. Maternally inherited mutations typically lead to hormone resistance and Albright's hereditary osteodystrophy (AHO), characterised by short stature, round facies, brachydactyly and subcutaneous ossifications. Paternal inheritance presents with features of AHO or ectopic ossification without hormone resistance. This report describes the case of a child with osteoma cutis and medulloblastoma. The objective of this report is to highlight the emerging association between inactivating germline GNAS mutations and medulloblastoma, aiming to shed light on its implications for tumor biology and promote future development of targeted surveillance strategies to improve outcomes in paediatric patients with these mutations. CASE PRESENTATION: A 12-month-old boy presented with multiple plaque-like skin lesions. Biopsy confirmed osteoma cutis, prompting genetic testing which confirmed a heterozygous inactivating GNAS mutation. At 2.5 years of age, he developed neurological symptoms and was diagnosed with a desmoplastic nodular medulloblastoma, SHH molecular group, confirmed by MRI and histology. Further analysis indicated a biallelic loss of GNAS in the tumor. CONCLUSIONS: This case provides important insights into the role of GNAS as a tumor suppressor and the emerging association between inactivating GNAS variants and the development of medulloblastoma. The case underscores the importance of careful neurological assessment and ongoing vigilance in children with known inactivating GNAS variants or associated phenotypes. Further work to establish genotype-phenotype correlations is needed to inform optimal management of these patients.

Detection of Cutibacterium acnes from multiple miliary osteoma cutis.

The patient had a history of acne vulgaris at a young age. The excisional biopsy from the nodule of the face showed the findings of multiple miliary osteoma cutis (MMOC). As Cutibacterium acnes were identified in calcified nodules, Cutibacterium acnes may be one of the triggering factors for MMOC. MMOC patients need proper skin care because the subcutaneous calcification is slowly formed even after middle age.

Early Diagnosis of Pseudohypoparathyroidism before the Development of Hypocalcemia in a Young Infant.

Pseudohypoparathyroidism (PHP) is a rare, heterogeneous disorder characterized by end-organ resistance to parathyroid hormone (PTH). PTH resistance causes elevated PTH levels, hypocalcemia, and hyperphosphatemia. Since hypocalcemia causes life-threatening events, early diagnosis is crucial. However, the diagnosis of PHP is elusive during infancy because PHP is usually diagnosed with hypocalcemia-induced symptoms, which develop later in childhood when calcium requirements increase. A 1-month-old girl was referred to our clinic for elevated thyroid-stimulating hormone (TSH) levels on newborn screening. When measured 1 month after levothyroxine treatment, her TSH level normalized. At 4-months-old, multiple hard nodules were noted on her trunk. A punch skin biopsy revealed osteoma cutis associated with Albright's hereditary osteodystrophy, a major characteristic of PHP. We performed targeted sanger sequencing of the GNAS gene and detected a heterozygous variant c.150dupA (p.Ser51Ilefs*3) in both the proband and her mother, causing frameshift and premature termination mutations. The patient was diagnosed with PHP Ia when she had normal calcium, phosphorous, and PTH levels. We report the early diagnosis of PHP Ia without hypocalcemia. It emphasizes the importance of meticulous physical examination in patients with congenital hypothyroidism.

A Case of Surgical Removal of a Giant and Multiple Acquired Plate-Like Osteoma Cutis After Implantation of a Dilator.

Osteoma cutis (OC) is a group of rare skin ossification diseases, most of which are secondary to inflammation, scarring, trauma, or tumors, but a small portion are primary. Plate-like osteoma cutis is rare, especially after puberty. This report documents a case of a 30-year-old female, who presented with multiple stone-hard plates on the forehead and bilateral temples, with no relevant family history, or abnormalities in metabolism. These lesions showed slow progression over the last 11 years. The pathological diagnosis confirmed osteoma cutis. The forehead lesions were treated surgically due to aesthetic problems. In addition, long-term follow-up and observations are still needed to determine progression to deeper levels of tissue.

Progressive Primary Plate-Like Osteoma Cutis of the Scalp.

Osteoma cutis (OC) or cutaneous ossification refers to uncommon bone formation in the skin. Primary OC develops without any predisposing factor or pre-existing lesion, whereas secondary OC sets out as a dystrophic ossification following traumatic, cicatricial, and neoplastic factors or other cutaneous inflammations. Herein, we report a rare case of long-standing progressive primary OC of the scalp resected in 3 sessions with no recurrence after 1 year.

Progressive Osseous Heteroplasia: A Rare Case Report.

Progressive osseous heteroplasia (POH) is a rare genetic condition of progressive extraskeletal bone formation. POH is clinically suspected by cutaneous ossification, usually presenting in early life, that involves subcutaneous and then subsequently deep connective tissues, including muscle and fascia. We report a case of POH in a 3-year-old child with multiple nontender subcutaneous nodules which, on radiology and histopathology, showed intracutaneous bone formation. Although there is no specific and effective treatment, knowledge about this entity is necessary for early detection and genetic counseling of parents.

Multiple miliary osteoma cutis treatment response to Q-switched Nd:YAG laser: A case report.

Facial multiple miliary osteoma cutis is a variant of osteoma cutis usually occurring in women with a previous history of acne vulgaris. Successful ablative laser treatment has been reported using both CO2 and Er:YAG lasers among other invasive treatment modalities, like surgical removal. We report a patient with biopsy-proven facial multiple miliary osteoma cutis responding to non-ablative Q-switched Nd:YAG laser therapy. The patient had excellent cosmesis without textural changes or hypopigmentation despite her Asian background after three sessions over 6 months. Multiple miliary osteoma cutis is therefore now amenable to non-surgical non-ablative therapy by using Q-switched Nd:YAG laser therapy reducing the risk of textural changes and hypopigmentation, especially in dark complexion and high-risk individuals. To our knowledge, this treatment approach has not been previously reported.

Primary Osteoma Cutis in the Interscapular Region of a Dog.

A 9-year-old neutered male Shih Tzu was presented with three contiguous firm nodules in the subcutaneous tissue of the interscapular region. Histopathological examination revealed that the nodules consisted of mature lamellar bone with a Haversian system, with no apparent lesion around the bone. Clinical examination revealed that the dog had no underlying disease and no history of trauma at the lesion site. Based on these findings and on the medical history, a diagnosis of primary osteoma cutis was made. Osteoma cutis is rare in both human and veterinary medicine, and most dogs reported to have secondary osteoma cutis. To our knowledge, this case is only the second report of primary osteoma cutis in a dog.

Multiple miliary osteoma cutis: a comprehensive review and update of the literature.

Multiple miliary osteoma cutis consists of heterotopic foci of bone tissue in the dermis and subcutaneous tissue. Patients usually present with multiple, asymptomatic facial papules of several millimetres in diameter which cause distress regarding their cosmetic appearance. The condition is described as rare, as only a few cases have been reported since its first description in 1864 by Virchow. We therefore carried out a comprehensive literature search and review, in which 102 published cases were retrieved and analysed. The demographic and clinical aspects, as well as current therapy solutions, of this probably overlooked condition are discussed.