13 - 77 - HYPERMELANOSES Flashcards
- congenital condition causing** diffuse streaky hyperpigmented macules along the lines of Blaschko** without preceding inflammation or atrophy in the first few weeks of life
- Lesions are typically located on the trunk and limbs and do not cross the midline.
- Face, palms, soles, eyes, and mucous membranes are spared.
Linear and whorled nevoid hypermelanosis
X-linked dominant disorder resulting from mutation in the IKBKG (previously called NEMO) gene.
INCONTINENTIA PIGMENTI
- Congenital diffuse reticular hyperpigmentation with nail atrophy and leukoplakia.
- Manifests in the first few years of life.
- Extracutaneous manifestations are bone marrow failure and malignancies.
DYSKERATOSIS CONGENITA
- **Reticulate hyperpigmentation **is most prominent in **neck and axillae. **
* Palmoplantar diffuse keratoderma, **absence of dermatoglyphs, nail and teeth changes, **and heat intolerance owing to diminished or absent sweating are characteristic.
NAEGELI-FRANCESCHETTI- JADASSOHN SYNDROME
Naegeli-Franceschetti-Jadassohn syndrome and the related dermatopathia pigmentosa reticularis are autosomal dominant ectodermal dysplasias caused by mutations in what keratin?
KRT14 gene
* Reticulate hyperpigmentation on the trunk,
* **palmoplantar keratoderma **with punctiform accentuation,
* **nail and ocular **changes,
* noncicatricial alopecia,
* ichthyosis,
* hypohidrosis,
* widespread hyperkeratotic lesions,
* ainhum formation,
* severe periodontal disease,
* mechanic blister formation, and
* pigmentation of the oral mucosa
DERMATOPATHIA PIGMENTOSA RETICULARIS
- Autosomal dominant
- Numerous small symmetrical brown-gray macules usually begin in the groin and axillae in the third or fourth decade of life and then spread to intergluteal and inframammary folds, neck, trunk, and arms.
- Comedo-like hyperkeratotic follicular papules on the neck and axilla and pitted perioral acneiform scars also appear.
DOWLING-DEGOS DISEASE
mutation in DOWLING-DEGOS DISEASE
KRT5 gene
- show the diagnostic features of Dowling-Degos disease with the additional histopathologic finding of acantholysis in suprabasal epidermal layers
- It is regarded as the **acantholytic variant of Dowling-Degos disease. **
- Mutations in the keratin 5 gene have been found in some patients.
Galli-Galli disease
* angular and sharply demarcated reticulate, freckle-like hyperpigmented macules beginning on the dorsa of the hands during the first decade of life and subsequently spreading to the rest of the body
* The **macules are slightly depressed; **sometimes palmar pits can be observed.
* Most cases are from Japan.
Kitamura reticular acropigmentation
Mutations in the ADAM10 gene
- reticulate pigmentation on trunk and axillae
- verruciformis papular lesions of the trunk and a distinct photosensitive rosacea-like facial erythema and telangiectasias, most commonly presenting in childhood
HABER SYNDROME
Nevus of ota presents with unilateral blue-black or gray-brown dermal melanocytic pigmentation that is typically seen in areas innervated by what cranial nerve?
first and second branches of the trigeminal nerve
Of those affected with nevus of ota, how many % have scleral pigmentation?
60%
Other sites of mucosal pigmentation include the conjunctiva and tympanic membrane (oculodermal melanocytosis)
subclassifications of nevus of Ota
mild (Type 1),
moderate (Type 2),
intensive (Type 3),
bilateral (Type 4)
Malignancy that rarely develop in a nevus of Ota
Malignant melanoma
- this necessitates careful followup of the lesion, especially if it occurs in white patients, in whom malignant degeneration seems to be more frequent.
- Malignant melanocytic tumors in association with nevus of Ota have been shown to arise in the chorioidea, brain, orbit, iris, ciliary body, and optic nerve.
- association with **ipsilateral glaucoma **and intracranial melanocytosis has been described.
Various triggers that have been described in nevus of ota.
infection, trauma, ultraviolet light exposure, and hormonal influences,
Well-circumscribed, blue-tinged hyperpigmented macules in the sacral area are most commonly seen
Mongolian spots
- also can be found in the gluteal and lumbar regions and on the thorax, abdomen, arms, legs, and shoulders
Several cases are described with extensive Mongolian spots involving large areas of the trunk and extremities that are associated with what condition?
inborn errors of metabolism, such as lysosomal storage diseases, GM1-gangliosidosis and mucopolysaccharidosis
Histologically, these macules consist of **spindle-shaped melanocytes **in the lower dermis that have failed to migrate to the dermal–epidermal junction during fetal life.
Mongolian spots
nerve distribution of nevus of Ito
Acromioclavicular nerve
More than half of all cases of Peutz-Jeghers Syndrome can be attributed to a mutation in what?
STK11 (LKB1)
hallmarks of Peutz-Jeghers Syndrome
Mucocutaneous pigmentation and intestinal hamartomatous polyposis
most common malignancies associated with PJS
GI (small intestine, colorectal, stomach, pancreas)
but nongastrointestinal neoplasms, such as breast, cervix, and endocrine tumors (thyroid, testicular, ovarian), have been described.