Dermal and Subcutaneous Tumors

Mastocytosisurticaria pigmentosaLocal and systemic accumulations of mast cellsPersistent pigmented itchy skin lesionsUrticate on mechanical or chemical irritationc-KIT mutationBirth to middle age, < 6 mo

Macules, papules, nodules, plaques, vesiclesLesions persist and gradually become chamois- or slate-coloredDariers sign, pruritisSevere symptoms may result from massive liberation of histamine from mast cells after ingestion of known mast cell degranulatorsSpontaneous resolution is likely in those pts whose disease began in childhood

Urticaria pigmentosa

Solitary mastocytomaMay be present at birth, may develop during the first weeks of lifeBrown macule that urticates upon strokingSmooth or peau d orangeDorsum of the hand near the wristEdema, urtication, vesiculation may be observed

Generalized eruption, childhood typePseudoxanthomatous mastocytosisDiffuse cutaneous mastocytosisGeneralized eruption, adult typeErythrodermic mastocytosisTelangiectasia macularis erupta perstansSystemic mastocytosisFamilial urticaria pigmentosa

Giemsa, azure A, or polychrome toluidine blueLocal anesthetic adjacent to the lesion, without epiDx is bx confirmedHistamine metabolites methylhistamine and methylimidazole acetic acid

Prognosis and treatmentIn all forms without systemic involvement the prognosis is goodSolitary lesions usually involute within 3 yearsH1 and H2 blockersPUVAIntralesional and topical steroidsAvoid physical stimuli

Abnormalities of neural tissue

Solitary neurofibromaSoft, flaccid, pinkish white, 2-20 mmInvaginates on pressure, buttonholingSolitary or multipleDistinctive histopathologic findings, fibrils, cellular proliferation, and degenerative changesSx excision

Granular cell tumorWell-circumscribed, solitary firm nodule, with a brownish red or flesh tintUsually solitary, 10-15 % multiple1/3 of cases have occurred on the tongueMay occur anywhere on the bodyGrows slowlyCells stain positively with vimentin, neuron-specific enolase, S-100, and myelin proteinMalignant granular cell tumor is rare

Neuroma cutisThree true neuromas exist in the skin and mucous membranes: traumatic neuroma, multiple mucosal neuromas, and solitary palisaded encapsulated neuromasTraumatic neuromas occur commonly on the fingers, tender and painfulMultiple mucosal neuromas occur as part of multiple mucosal neuroma syndromesolitary palisaded encapsulated neuromas occur commonly on the face, resembles BCC

neurothekeomaNerve sheath myxomaBenign tumor of nerve sheathMitotic figures and nuclear atypia are sometimes observedIntradermal or subcutaneousHistologically are divided into two subtypes: myxoid and more common cellular variant

schwannomaneurilemmomaUsually a solitary nerve sheath tumorMost often seen in womenOccur almost exclusively along the main nerve trunks of the extremitiesSoft or firm nodules, may be painfulMay be multiple May be assoc. with NF-1 or NF-2

Occur in many other organsexcision

Infantile neuroblastomaThe most common malignant tumor of childhoodCutaneous nodule are most often seen in the younger patientsBlue nodules the when rubbed form a halo of erythemaPeriorbital ecchymoses and heterechromiaGood prognosis for patients with skin involvement, spontaneous remission

ganglioneuromaRarely described in the skin as an isolated entityArise most often in von Recklinghausens neurofibromatosisOccur in childhood

Nasal gliomaCephalic brainlike heterotopiasRare, benign congenital tumorsEasily confused with hemangiomasFirm, reddish blue lesion on the nasal bridgeNo connection with the subarachnoid spaceRadiography and neurosurgical consultationDoes not involute spontaneously

Cutaneous memingiomaPsammomaResults from the presence of meningocytes outside the calvariumSmall, hard, fibrous, calcified nodules occurring along the spine, in the scalp, and on the foreheadUsually seen within the first yearNo distinctive appearance, dx by histo

Encephalocele and MeningocelePrimary defect in the neural tube Present in infancy along the midlineCompressible masses that may transilluminate or enlarge with cryingMidline masses require intensive radiologic and neurosurgical evaluation before biopsy

chordomasSlow-growing, locally invasive Firm, smooth nodules in the sacralcoccygeal region or at the base of the skullArise from notochord remnantsMay metastasize late in their courseWide excision and postoperative radiation therapy

Abnormalities of Fat Tissue

lipomasSubcutaneous tumors composed of fat tissueMost commonly found on the trunkAlso neck, forearms and axillaeSoft, single or multiple, lobulated and compressibleGrowth to size and remain stationaryagain be careful of sacrococcygeal lipomasLesion may be left untreated or excised

Solitary lesions reaching greater than 10 cm should be investigated for malignancyMultiple lesion may be painful if growing rapidlyMadelungs disease, benign symmetric lipomatosisDercums disease, assoc with weakness and psychiatric disturbances

Familial multiple lipomatosis, AD inheritanceBannayan-Riley-Ruvalcaba syndromeMEN 1Frohlichs syndromeGardners syndrome

angiolipomaA painful subcutaneous nodule just slightly above the level of the skinHas all other typical features of a lipomaSeen in young adults who have multiple painful lumps in the skinMultiple subcutaneous angiolipomas have no invasive or metastatic potential

Neural fibrolipomaOvergrowth of fibro-fatty tissueOccurs along a nerve trunk and often leads to compressionSlowly enlarging subcutaneous mass with tenderness and decreased sensation or parasthesiaMedian nerve is most commonly involvedMRI, no effective treatment

Spindle-cell lipomaAsymptomatic, slow growing subcutaeneous tumorPredilection for the back and neck and shoulders of older menConsists of lobulated masses of mature adipose tissue

Painful Piezogenic pedal papulesTransitory, soft, sometimes painful papules on the sides of the heelsElicited by weight-bearing and disappearing when this is stoppedOccur in at least 75 % of normal individualsSuitable supportive shoes may alleviate discomfortMay occur on the wrist

Nevus lipomatosus superficialisSoft, yellowish papule or ceribriform plaques, usually of the buttock or thigh, less often the ear or scalpA wrinkled surface characterizes this tumorOnset prior to age of 20

Nevus lipomatosus superficialis

Folded skin with scarringRare, aka Michelin Tire Baby SyndromeThere are numerous deep, conspicuous, symmetrical, ringed creases around the extremitiesThe underlying skin may manifest a smooth muscle hamartoma, a nevus lipomatosis, or elastic tissue abnormalitiesAD, sporadic or an isolated finding assoc with congenital facial and limb abnormalities

Diffuse lipomatosisCharacterized by an early age of onset, by the age of 2, diffuse infiltration of muscle by and encapsulated mass of mature lipocytesProgressive enlargement and extensionUsually involves a large portion of the trunk or extremity

Hibernoma(lipoma of brown fat)A form of lipoma composed of finely vacuolated fat cells of embryonic typeHave a distinctive brownish color and a firm consistencyBenign and usually occur singlyChiefly in the mediastinum and the interscapular regionOnset usually in adult life

Pleomorphic lipomaOccur for the most part on the backs and necks of elderly menOccasional lipoblast-like cells and atypical mitotic figures may require differentiation from a liposarcomaBehave in a perfectly benign manner`

Benign lipoblastomatosisFrequently confused with a liposarcomaAffects exclusively infants and young children, 90% < age 3Commonly involves the soft tissues of the upper or lower extremityA circumscribed and a diffuse form can be distinguishedTOC- complete local excision

liposarcomaOne of the less common mesenchymal neoplasms of the soft tissueUsually arise from intermuscular fasciaDo not arise from preexisting lipomasUsual course is an inconspicuous swelling of the soft tissue with gradual enlargementWhen a fatty tumor becomes greater than 10 cm DX should be consideredUpper thigh is the most common site

Adult males are mostly affectedMay be well or poorly differentiated Tx is adequate radical excision For metastatic liposarcomas, radiation therapy may be effective

Abnormalities of smooth muscle

leiomyomaSmooth muscle tumorsCharacterized by painful nodulesSingly or multipleBenignTreatment is directed toward the removal of the pain sourceSimple excision is best

Solitary cutaneous leiomyomaMultiple cutaneous leiomyomasSolitary genital leiomyomaangioleiomyoma

Grouped leiomyomata of the back

Congenital smooth muscle hamartomaTypically a skin colored or slightly pigmented patch or plaque with hypertrichosis Often present at birthUsually seen on the trunk, lumbosacral area in 2/3Michelin tire baby syndrome may result from a diffuse smooth muscle hamartoma

Clinically may mimic a mastocytoma, pseudo-Dariers sign is seen in 80%No treatment is necessary

leiomyosarcomaOf soft tissue origin are extremely rareMay occur as metastasis from internal sourceAppears in the dermis as a solitary nodule, good prognosisSubcutaneous lesions have a guarded prognosis, with fatal hematogenous metastases in 1/3WLE or Mohs

Miscellaneous tumors and tumor-associated conditions

Cutaneous endometriosisBrownish papules in the umbilicus or lower abdominal scars after gynecologic surgeryTender or painful lesionsBluish black from cyclic bleedingUsually misdiagnosed as malignant metastasesSurgical excisionPreoperative tx with danazol or leuprolide may reduce size

teratomaMay develop in the skin but are most common in the ovaries or testesNo characteristic clinical featuresTissue representing all three germ layers are presentOccasionally malignancy may occur

Metastatic carcinoma5 to 10% of patients with cancer develop skin metastasesUsually present as numerous firm, hard, or rubbery massesPredilection for chest, abdomen or scalpSister Mary Joseph nodule, metastatic tumor localized to the umbilicus, most common primary sites include the stomach, large bowel, ovary and pancreas

A poor prognosis is usually the ruleThe involvement of the skin is likely to be near the area of the primary tumorBreast cancer is the type most commonly metastatic to the skin in women and melanoma followed by lung cancer in menMetastatic lesions are uncommon in children

Paraneoplastic syndromesSome cancers produce findings in the skin that indicate to the clinician that an underlying internal malignancy may be presentBazexs syndrome, characterized by violaceous erythema and scaling of the fingers, toes, nose, and aural helices.Secondary to a primary malignant neoplasm of the upper aerodigestive tract

Bazexs syndrome

Necrolytic migratory erythema, seen with glucagon-secreting tumors of the pancreasErythema gyratum repens, erythema with characteristic wood-grain-pattern scales, is almost always associated with and underlying malignancyHypertrichosis lanuginosa aquisata, most common with lung and colon ca

EGR

Erythema gyratum repens

Hypertrichosis lanuginosa

The sign of Lesser-Trelat, the sudden appearance of multiple pruritic seborrheic keratosis, associated with and internal malignancyTrousseaus sign, migratory thrombophlebitis, pancreatic caPityriasis rotundaTripe palmsSeveral others with less frequency

carcinoidCharacterized by distinctive involvement of the lungs, heart, gastrointestinal tract and the skinCutaneous flushing lasting 5-10 minutesInvolves the head and neck producing a scarlet colorCyanosis may be presentEpisodic flushing continues for months or years

The release of excessive amounts of serotonin and bradykinen into circulation produces attacks of flushing of the skin, weakness, abdominal pain, nausea and vomiting, sweating, palpitation, diarrhea and collapseTumor arises from the argentaffin Kulchitsky chromaffin cells of the appendix or terminal ileum (gi, lungs, ovaries, testes)

The diagnosis may be established by finding high levels of 5-hydroxyindolacetic acid (5-HIAA) in the urineTx- primary tumor should be removed, and excision of metastatic lesion should be consideredChemotherapy