Regular skin exams can identify suspicious lesions, but an accurate diagnosis requires a biopsy. During the biopsy, a doctor will inject a local anesthetic in the area of the lesion and then remove a sample of the lesion (sometimes the entire lesion) and send it to a laboratory for analysis.
In most cases, a doctor will perform an excisional biopsy to remove tissue for examination. Several types of excisional biopsies are used for melanoma diagnosis: deep-shave technique (also called saucerization); elliptical (full thickness); or punch biopsy, which involves removing a piece of tissue with a hand-held device.
Most studies have shown that the type of biopsy does not affect diagnostic accuracy or clinical outcomes. In some cases, usually involving flat skin lesions, a doctor may perform an incisional biopsy, which is a smaller procedure that involved less tissue.
When examined through a microscope, melanoma cells have a distinct makeup and distribution that distinguish them from normal skin cells and from benign growths, such as moles and warts. Pathologists are trained to recognize the differences and determine whether a lesion is malignant or benign.
The pathologist summarizes the findings from a biopsy in a report for the doctor who performed the biopsy. If the skin lesion is not cancerous, the report will include details about the cellular makeup and distribution of the cells and describe the type of skin lesion associated with those features.
If the findings indicate melanoma, the report will include information about how advanced the cancer is and about factors that influence the likelihood that the melanoma will progress or spread. The features below will be included in the reports if noted:
- Breslow thickness -- The measured thickness of the melanoma and how far it extends into the skin
- Ulceration -- Breakdown of skin on the melanoma, a marker of increased risk
- Mitotic rate -- A measure of how fast the cancer cells are growing and dividing
- Margin status -- How close the cancer cells are to the edges of the biopsy
- Microsatellites -- Microscopic clusters or nests of tumor cells that can be seen or felt as a nodule near the primary tumor
- In-transit melanoma -- Cell clusters that have migrated farther from the primary lesion but have not reached a lymph node
Pathologists include what they consider to be the essential information about a melanoma lesion, and that can vary from one pathologist to another. Additionally, treating physicians may request specific types of information. Patients should talk with their doctors about the information in a pathology report and about how to interpret the information.
Types of Melanoma
Melanoma has several subtypes or histologies that are defined by the specific types of cells that make up the lesion. Some pathologists and other doctors consider this essential information, and it may be included in the pathology report.
- The most common subtype is superficial spreading melanoma, often found on the chest, abdomen, and legs. About 70% of all melanomas fall into this category
- The next most common is nodular melanoma (15-20% of lesions), which tends to grow quickly and accounts for about half of all melanoma deaths. The lesion often appears as a large black bump that resembles a mole, bug bite, or pimple. These types of lesions tend to arise on skin areas that have a lot of sun exposure: the legs, torso (including the back), arms, and head
- Pure desmoplastic melanoma (less than 5% of lesions) is a firm, plaque-like lesion and often occurs on the face, shoulders, or scalp. The lesions tend to be thicker than superficial spreading melanomas and are associated with an increased risk of recurring in the skin
- Acral lentiginous melanoma is another uncommon subtype and arises in unusual locations, such as the soles of the feet, palms of the hands, fingertips, and under the nails. This subtype occurs more often in dark-skinned individuals
- Lentigo maligna is a superficial lesion that typically appears as an irregular brown patch on the head or neck and is associated with chronically sun-damaged skin. When deeper penetration into the skin occurs, physicians may refer to the lesion as lentigo maligna melanoma
The melanoma stage at diagnosis represents how far the lesion has penetrated into the skin and whether it has spread away from the primary tumor to lymph nodes or other organs.
Stage 0 (often described as melanoma in situ) is limited to the skin surface.
Lesions that are stages I or II have penetrated below the surface but remain in the uppermost levels of the skin. Stages I and II are further subdivided on the basis of melanoma thickness and other factors that are associated with an increased risk of becoming more invasive or advanced.
Stage III melanoma (also called locally advanced) has spread to one or more lymph nodes or the surrounding tissue often leading to the closest lymph nodes. The stage is subdivided into stages IIIA through IIID, according to the melanoma's thickness, presence or absence of ulceration, number of lymph nodes affected, presence of microsatellites or in-transit disease, and other factors that determine the risk of continued progression.
Stage IV means that the disease has spread beyond the primary tumor and lymph nodes to other organs in the body.
Imaging and Laboratory Tests
In general, imaging studies (x-ray, CT, MRI) and laboratory tests have little role in the initial diagnosis of primary melanoma. They play a more prominent role in planning treatment and determining response to treatment for patients with stages III and IV disease. Similarly, tests for genetic mutations in the tumor play a greater role in determining the type of medical treatment that might be used for melanoma, particularly for patients with stage IV (metastatic) melanoma, for which surgery is usually not recommended.
Read previous installments in this series:
"Medical Journeys" is a set of clinical resources reviewed by doctors, meant for physicians and other healthcare professionals as well as the patients they serve. Each episode of this 12-part journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.
Uchunguzi wa kawaida wa ngozi waweza kutambua vidonda vyenye kutilika shaka, lakini utambuzi sahihi huhitaji uchunguzi wa ngozi. Wakati wa upasuaji, daktari huingiza dawa ya kuua maumivu katika eneo la ugonjwa na kisha huondoa sampuli ya ugonjwa (wakati mwingine ugonjwa wote) na kuipeleka kwenye maabara kwa ajili ya uchambuzi. Katika visa vingi, daktari atafanya upasuaji wa kuondoa tishu ili kuchunguzwa. Biopsia ya excision ni aina ya upasuaji unaotumiwa kugundua ugonjwa wa melanoma: upasuaji wa kupasua nywele kwa kina (unaoitwa pia saucerization), upasuaji wa elliptical (upana kamili), au upasuaji wa punch, ambao unahusisha kuondoa kipande cha tishu kwa kutumia kifaa cha mkono. Uchunguzi mwingi umeonyesha kwamba aina ya upasuaji haathiri usahihi wa utambuzi au matokeo ya kliniki. Katika kesi za kawaida, ikiwa ni pamoja na vidonda vya ngozi, daktari anaweza kufanya upasuaji wa kupasua, ambayo ni utaratibu mdogo ambao unahusisha tishu chache. Chembe za melanoma zinapochunguzwa kwa darubini, zina muundo na usambazaji tofauti ambao huwatenganisha na chembe za ngozi za kawaida na ukuzi wa kawaida, kama vile moles na warts. Wataalamu wa magonjwa ya magonjwa wamefundishwa kutambua tofauti hizo na kuamua ikiwa kidonda hicho ni kibaya au kibaya. Mtaalamu wa magonjwa ya magonjwa hukusanya matokeo ya uchunguzi wa viini katika ripoti kwa daktari aliyefanya uchunguzi huo. Ikiwa ugonjwa wa ngozi sio kansa, ripoti hiyo itajumuisha maelezo juu ya muundo wa seli na usambazaji wa seli na kuelezea aina ya ugonjwa wa ngozi unaohusishwa na sifa hizo. Ikiwa matokeo yanaonyesha melanoma, ripoti hiyo itajumuisha habari kuhusu jinsi kansa hiyo ilivyo katika hatua ya juu na kuhusu mambo yanayoathiri uwezekano wa melanoma kuenea au kuenea. "Hii ni pamoja na: ""Urefu wa Breslow"" - ""Urefu wa kipimo cha melanoma na jinsi inavyoenea kwenye ngozi"" - ""Urefu wa ulceration"" - ""Uharibifu wa ngozi kwenye melanoma, alama ya hatari iliyoongezeka"" - ""Mitotic rate"" - ""Urefu wa jinsi seli za kansa zinavyoongezeka na kugawanyika"" - ""Marginal status"" - ""Urefu wa seli za kansa kwenye kingo za biopsia"" - ""Microsatellites"" - ""Mikusanyo ndogo au viota vya seli za uvimbe ambazo zinaweza kuonekana au kuhisi kama nodule karibu na uvimbe wa msingi - ""In-transit melanoma"" - ""Cell paths"" ambazo zimehamia mbali zaidi kutoka kwa uvimbe wa msingi." Kwa kuongezea, madaktari wanaotunza wagonjwa wanaweza kuomba aina fulani za habari. Wagonjwa wanapaswa kuzungumza na madaktari wao kuhusu habari katika ripoti ya ugonjwa na jinsi ya kutafsiri habari hiyo. Aina za Melanoma: Aina za Melanoma ni aina ndogo za aina ya chembe zinazofanyiza chembe. Wataalamu fulani wa magonjwa na madaktari wengine huona habari hiyo kuwa muhimu, na huenda ikaingizwa katika ripoti ya magonjwa. - Aina ya chini ya kawaida ni melanoma ya juu inayoenea, ambayo mara nyingi hupatikana kwenye kifua, tumbo, na miguu. Karibu asilimia 70 ya melanomas zote huanguka katika jamii hii - ya pili ya kawaida ni nodular melanoma (15-20% ya majeraha), ambayo huwa na kukua haraka na inahesabu karibu nusu ya vifo vyote vya melanoma. Mara nyingi kidonda hicho huonekana kama kidonda kikubwa chenye rangi nyeusi kinachofanana na chembechembe, kuumwa na wadudu, au kidonda. Aina hizi za majeraha huonekana kwenye sehemu za ngozi ambazo zina jua nyingi: miguu, torso (pamoja na nyuma), mikono, na kichwa - Melianoma ya desmoplastic safi (chini ya 5% ya majeraha) ni ya kudumu, kama plaque, na mara nyingi hutokea kwenye uso, mabega, au ngozi. Ugonjwa huu unaonekana kuwa mkubwa kuliko melanomas ya uso na unahusishwa na hatari ya kuongezeka kwa mara nyingine tena kwenye ngozi - Acral lentiginous melanoma ni aina nyingine isiyo ya kawaida na hutokea katika maeneo yasiyo ya kawaida, kama vile nyayo za miguu, mikono, vidole vya vidole, na chini ya misumari. Lentigo maligna ni ugonjwa wa uso ambao kwa kawaida huonekana kama doa la kahawia lisilo la kawaida kwenye kichwa au shingo na huhusishwa na ngozi iliyoharibiwa na jua. "Wakati upasuaji wa ngozi unaendelea, ugonjwa wa ""lentigo maligna"" huonekana katika sehemu ya ngozi, na hatua ya ugonjwa wa ""melanoma"" huonyesha jinsi ugonjwa huo umeenea kutoka kwenye uvimbe wa msingi hadi kwenye nyuzi za lymph." "Mwisho wa hatua ya kwanza, ""melanoma in situ,"" huonekana kwenye sehemu ya juu ya ngozi." Majeraha ya hatua ya kwanza au ya pili yameingia chini ya uso lakini hubaki katika ngazi za juu za ngozi. Hatua ya kwanza na ya pili ya ugonjwa huo hugawanywa kulingana na unene wa melanoma na sababu nyingine zinazohusiana na hatari ya kuambukizwa au kuenea. Melanoma ya hatua ya tatu (inaitwa pia ya juu ya ndani) imeenea kwa kibofu kimoja au zaidi au tishu inayozunguka mara nyingi inayoongoza kwa kibofu cha karibu zaidi. Ugonjwa huo umegawanywa katika hatua IIA hadi IID kulingana na unene wa melanoma, uwepo au kutokuwepo kwa ulceration, idadi ya lymph nodes zilizoathiriwa, uwepo wa microsatellites au ugonjwa wa usafiri, na mambo mengine ambayo huamua hatari ya kuendelea. Hatua ya nne ni kwamba ugonjwa umeenea zaidi ya uvimbe wa msingi na kibofu cha lymph kwenye viungo vingine vya mwili. Kwa ujumla, uchunguzi wa picha (X-ray, CT, MRI) na vipimo vya maabara vina jukumu dogo katika utambuzi wa awali wa melanoma ya msingi. Utafiti huo unaonyesha kuwa ni muhimu sana kwa ajili ya kuamua jinsi ya matibabu ya wagonjwa walio katika hatua ya tatu na ya nne. Kwa mfano, uchunguzi wa mabadiliko ya chembe za urithi katika uvimbe una jukumu kubwa katika kuamua aina ya matibabu ambayo yanaweza kutumika kwa melanoma, hasa kwa wagonjwa wenye hatua ya nne (metastatic) melanoma, ambayo upasuaji kwa kawaida haupendekezi. "Mapendekezo ya ""Mafunzo ya Matibabu"" ni seti ya rasilimali za kliniki zilizochunguzwa na madaktari, zinazolenga madaktari na wataalamu wengine wa huduma za afya na wagonjwa wanaowahudumia." Kila sehemu ya safari hii ya sehemu 12 kupitia hali ya ugonjwa ina mwongozo wa daktari na rasilimali ya mgonjwa inayoweza kupakuliwa au kuchapishwa. "Safari za Matibabu" huonyesha njia kila hatua ya njia kwa madaktari na wagonjwa na hutoa rasilimali na msaada wa kuendelea, wakati timu ya watunzaji inasafiri mwendo wa ugonjwa.