1_Dermoscopy Pt 2 Flashcards
what is dermoscopy?
- A non-invasive technique using a device that applies polarized light** and/or fluid that **eliminates the reflection of light from the surface of the skin
- allowing visualization of color and structure in the epidermis, DEJ, and papillary dermis
- generally a 10x fold magnification
what is the most common PRIMARY TUMOR of the foot?
MELANOMA,
specifically the superficial spreading type; ACRAL MELANOMA (incl nail)
why use dermoscopy in podiatry?
often diagnosis is delayed or misdiagnosed;
(melanoma has a 5 yr survival rate of 77% on foot vs. elsewhere on body)
we have been taught the ABCDs of melanoma, but what are the other tests to perform?
BIOPSY is the gold standard, but DERMOSCOPY can possibly prevent the need for a biopsy
why are acral melanomas difficult to monitor/diagnose?
ACRAL MELANOMAS don’t often look like the melanomas elsewhere;
recall: Acral lentiginous melanoma (ALM) is a form of skin cancer that appears on the palms of the hands, the soles of the feet, or under the nails
when is a dermatoscope used?
what can it distinguish?
- Suspicious lesion examine with dermatoscope
- Differentiates:
- melanocytic vs nonmelanocytic
- benign vs malignant)
- Determine if biopsy is needed for definitive diagnosis;
- IF no need to biopsy, continue to monitor or observe
what are the characteristics of MELANOMA w/ the dermatoscope?
(when NOT on palm or sole?)
- Asymmetrical, areas of regression, gray veil** (**shadowy-like feature)
how does melanoma present on the FOOT?
- Plantar vs dorsal skin –
- nevi vs melanoma,
- blue-white veil rarely seen plantarly, thickened skin makes pigmentation look skewed
- Nails – subungual hemorrhage, nevus, fungus, melanoma
when assessing ACRAL LESIONS on palms and soles, what presentation is benign?
-
“furrows are fine, ridges are risky”
- Furrow – depression in skin
- Ridge – elevation in skin
what is the “parallel pattern” with regard to dermoscopy of acral nevi
- ‘Parallel pattern’ refers to network seen within most melanocytic nevi on palmar and plantar surfaces
What are the 3 benign patterns for acral nevi?
- parallel furrow: pigmented furrows
- lattice-like: pigmented furrows and lines crossing these
- fibrillary: delicate pigmentation crossing skin markins
what pattern of acral nevi is MALIGNANT?
PARALLEL RIDGE is malignant (ridges are risky)
pigmented ridges (white dots represent sweat duct openings), highly specific for melanoma in volar sites
is there a distinct pattern in homogenous-type nevi on volar sites?
No obvious parallel pattern in homogenous-type nevi on volar sites
which skin presentation is described as “PEAS IN A POD”?
BENIGN ACRAL NEVUS;
globules are on ridges, and nevi cells surrounding eccrine ducts
when does a congenital benign acral nevus present?
Congenital - in terms of dermatology; means “up to one year of age”;
if pigmentation is in the furrows, it is likely …
BENIGN
(furrows are fine, ridges are risky)
what are some other uses of dermatoscopy other than melanoma?
- inflammation
- monitoring wart treatment
- distinguishing warts from calluses
- melanonychia (of nails)
- nail pigmentation, fungal infxn, hypertropy
dermatoscopy and inflammation:
differences b/w PSORIASIS and LICHEN PLANUS
how is dermatoscopy used for monitoring wart treatment?
- can also use the dermatoscope for warts; because it may look like the wart is gone but it may recur in 3 weeks
- As tx continues to progress, the skin lines start to reform; they are developing but “PUFFY”/papilloform;
- you want to confirm the skin lines have returned and are well-defined
dermatoscopy and distinguishing WART VS/ CALLUS:
skin lines
- Callus: SKIN LINES INTACT; pain straight on,
- Wart: INTERRUPTION OF SKIN LINES; pain on squeezing the sides
(BUT not 100%)
what are some of the causes of LONGITUDINAL MELANONYCHIA (LM)?
what can dermatoscopy identify about MELANIN INCLUSIONS?
- color: gray or brown;
- melanocytic activation
- no hyperplasia or hyperplasia
what is this dermatoscopic finding?
SUBUNGUAL HEMATOMA
what is the following dermatoscopic finding?
FUNGAL MELANONYCHIA
what are A-F in the following image?
- A = superficial stain,
- B = melanocytic activation,
- C = GRF from faulty biomechanics can lead to thickened nail,
- D = benign/gray,
- E = benign.
- F = malignant
are nails inert tissue?
NOPE;
Nails are not inert pieces of tissue, they are a water-based membrane
how does onychomycosis appear on dermatoscopy?
- spiked pattern, longitudinal striae, linear edge, distal irregular termination
what biomechanical change might be mistaken for toenail fungus?
With hammertoes, the patient is essentially, “walking on the nail” –>
causes the nail to hypertrophy; it is NOT a fungus
when assessing nails with dermoscopy, what step requires more evaluation?
Nails: Grey—is usually melanin activation, if brown determine further
