Dermal and Subcutaneous Tumors

Mastocytosis urticaria pigmentosa Local and systemic accumulations of mast cells Persistent pigmented itchy skin lesions Urticate on mechanical or chemical irritation c-KIT mutation Birth to middle age, ½ < 6 mo

Macules, papules, nodules, plaques, vesicles Lesions persist and gradually become chamois- or slate-colored Darier’s sign, pruritis Severe symptoms may result from massive liberation of histamine from mast cells after ingestion of known mast cell degranulators Spontaneous resolution is likely in those pts whose disease began in childhood

Urticaria pigmentosa

Solitary mastocytoma May be present at birth, may develop during the first weeks of life Brown macule that urticates upon stroking Smooth or peau d’ orange Dorsum of the hand near the wrist Edema, urtication, vesiculation may be observed

Generalized eruption, childhood type Pseudoxanthomatous mastocytosis Diffuse cutaneous mastocytosis Generalized eruption, adult type Erythrodermic mastocytosis Telangiectasia macularis erupta perstans Systemic mastocytosis Familial urticaria pigmentosa

Giemsa, azure A, or polychrome toluidine blue Local anesthetic adjacent to the lesion, without epi Dx is bx confirmed Histamine metabolites methylhistamine and methylimidazole acetic acid

Prognosis and treatment In all forms without systemic involvement the prognosis is good Solitary lesions usually involute within 3 years H1 and H2 blockers PUVA Intralesional and topical steroids Avoid physical stimuli

Abnormalities of neural tissue

Solitary neurofibroma Soft, flaccid, pinkish white, 2-20 mm Invaginates on pressure, “buttonholing” Solitary or multiple Distinctive histopathologic findings, fibrils, cellular proliferation, and degenerative changes Sx excision

Granular cell tumor Well-circumscribed, solitary firm nodule, with a brownish red or flesh tint Usually solitary, 10-15 % multiple 1/3 of cases have occurred on the tongue May occur anywhere on the body Grows slowly Cells stain positively with vimentin, neuron-specific enolase, S-100, and myelin protein Malignant granular cell tumor is rare

Neuroma cutis Three true neuromas exist in the skin and mucous membranes: traumatic neuroma, multiple mucosal neuromas, and solitary palisaded encapsulated neuromas Traumatic neuromas occur commonly on the fingers, tender and painful Multiple mucosal neuromas occur as part of multiple mucosal neuroma syndrome solitary palisaded encapsulated neuromas occur commonly on the face, resembles BCC

neurothekeoma Nerve sheath myxoma Benign tumor of nerve sheath Mitotic figures and nuclear atypia are sometimes observed Intradermal or subcutaneous Histologically are divided into two subtypes: myxoid and more common cellular variant

schwannoma neurilemmoma Usually a solitary nerve sheath tumor Most often seen in women Occur almost exclusively along the main nerve trunks of the extremities Soft or firm nodules, may be painful May be multiple May be assoc. with NF-1 or NF-2

Occur in many other organs excision

Infantile neuroblastoma The most common malignant tumor of childhood Cutaneous nodule are most often seen in the younger patients Blue nodules the when rubbed form a halo of erythema Periorbital ecchymoses and heterechromia Good prognosis for patients with skin involvement, spontaneous remission

ganglioneuroma Rarely described in the skin as an isolated entity Arise most often in von Recklinghausen’s neurofibromatosis Occur in childhood

Nasal glioma Cephalic brainlike heterotopias Rare, benign congenital tumors Easily confused with hemangiomas Firm, reddish blue lesion on the nasal bridge No connection with the subarachnoid space Radiography and neurosurgical consultation Does not involute spontaneously

Cutaneous memingioma Psammoma Results from the presence of meningocytes outside the calvarium Small, hard, fibrous, calcified nodules occurring along the spine, in the scalp, and on the forehead Usually seen within the first year No distinctive appearance, dx by histo

Encephalocele and Meningocele Primary defect in the neural tube Present in infancy along the midline Compressible masses that may transilluminate or enlarge with crying Midline masses require intensive radiologic and neurosurgical evaluation before biopsy

chordomas Slow-growing, locally invasive Firm, smooth nodules in the sacralcoccygeal region or at the base of the skull Arise from notochord remnants May metastasize late in their course Wide excision and postoperative radiation therapy

Abnormalities of Fat Tissue

lipomas Subcutaneous tumors composed of fat tissue Most commonly found on the trunk Also neck, forearms and axillae Soft, single or multiple, lobulated and compressible Growth to size and remain stationary again be careful of sacrococcygeal lipomas Lesion may be left untreated or excised

Solitary lesions reaching greater than 10 cm should be investigated for malignancy Multiple lesion may be painful if growing rapidly Madelung’s disease, benign symmetric lipomatosis Dercum’s disease, assoc with weakness and psychiatric disturbances

Familial multiple lipomatosis, AD inheritance Bannayan-Riley-Ruvalcaba syndrome MEN 1 Frohlich’s syndrome Gardner’s syndrome

angiolipoma A painful subcutaneous nodule just slightly above the level of the skin Has all other typical features of a lipoma Seen in young adults who have multiple painful lumps in the skin Multiple subcutaneous angiolipomas have no invasive or metastatic potential

Neural fibrolipoma Overgrowth of fibro-fatty tissue Occurs along a nerve trunk and often leads to compression Slowly enlarging subcutaneous mass with tenderness and decreased sensation or parasthesia Median nerve is most commonly involved MRI, no effective treatment

Spindle-cell lipoma Asymptomatic, slow growing subcutaeneous tumor Predilection for the back and neck and shoulders of older men Consists of lobulated masses of mature adipose tissue

Painful Piezogenic pedal papules Transitory, soft, sometimes painful papules on the sides of the heels Elicited by weight-bearing and disappearing when this is stopped Occur in at least 75 % of normal individuals Suitable supportive shoes may alleviate discomfort May occur on the wrist

Nevus lipomatosus superficialis Soft, yellowish papule or ceribriform plaques, usually of the buttock or thigh, less often the ear or scalp A wrinkled surface characterizes this tumor Onset prior to age of 20

Nevus lipomatosus superficialis

Folded skin with scarring Rare, aka Michelin Tire Baby Syndrome There are numerous deep, conspicuous, symmetrical, ringed creases around the extremities The underlying skin may manifest a smooth muscle hamartoma, a nevus lipomatosis, or elastic tissue abnormalities AD, sporadic or an isolated finding assoc with congenital facial and limb abnormalities

Diffuse lipomatosis Characterized by an early age of onset, by the age of 2, diffuse infiltration of muscle by and encapsulated mass of mature lipocytes Progressive enlargement and extension Usually 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 type Have a distinctive brownish color and a firm consistency Benign and usually occur singly Chiefly in the mediastinum and the interscapular region Onset usually in adult life

Pleomorphic lipoma Occur for the most part on the backs and necks of elderly men Occasional lipoblast-like cells and atypical mitotic figures may require differentiation from a liposarcoma Behave in a perfectly benign manner`

Benign lipoblastomatosis Frequently confused with a liposarcoma Affects exclusively infants and young children, 90% < age 3 Commonly involves the soft tissues of the upper or lower extremity A circumscribed and a diffuse form can be distinguished TOC- complete local excision

liposarcoma One of the less common mesenchymal neoplasms of the soft tissue Usually arise from intermuscular fascia Do not arise from preexisting lipomas Usual course is an inconspicuous swelling of the soft tissue with gradual enlargement When a fatty tumor becomes greater than 10 cm DX should be considered Upper thigh is the most common site

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

Abnormalities of smooth muscle

leiomyoma Smooth muscle tumors Characterized by painful nodules Singly or multiple Benign Treatment is directed toward the removal of the pain source Simple excision is best

Solitary cutaneous leiomyoma Multiple cutaneous leiomyomas Solitary genital leiomyoma angioleiomyoma

Grouped leiomyomata of the back

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

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

leiomyosarcoma Of soft tissue origin are extremely rare May occur as metastasis from internal source Appears in the dermis as a solitary nodule, good prognosis Subcutaneous lesions have a guarded prognosis, with fatal hematogenous metastases in 1/3 WLE or Mohs

Miscellaneous tumors and tumor-associated conditions

Cutaneous endometriosis Brownish papules in the umbilicus or lower abdominal scars after gynecologic surgery Tender or painful lesions Bluish black from cyclic bleeding Usually misdiagnosed as malignant metastases Surgical excision Preoperative tx with danazol or leuprolide may reduce size

teratoma May develop in the skin but are most common in the ovaries or testes No characteristic clinical features Tissue representing all three germ layers are present Occasionally malignancy may occur

Metastatic carcinoma 5 to 10% of patients with cancer develop skin metastases Usually present as numerous firm, hard, or rubbery masses Predilection for chest, abdomen or scalp Sister 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 rule The involvement of the skin is likely to be near the area of the primary tumor Breast cancer is the type most commonly metastatic to the skin in women and melanoma followed by lung cancer in men Metastatic lesions are uncommon in children

Paraneoplastic syndromes Some cancers produce findings in the skin that indicate to the clinician that an underlying internal malignancy may be present Bazex’s 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

Bazex’s syndrome

Necrolytic migratory erythema, seen with glucagon-secreting tumors of the pancreas Erythema gyratum repens, erythema with characteristic wood-grain-pattern scales, is almost always associated with and underlying malignancy Hypertrichosis 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 malignancy Trousseau’s sign, migratory thrombophlebitis, pancreatic ca Pityriasis rotunda Tripe palms Several others with less frequency

carcinoid Characterized by distinctive involvement of the lungs, heart, gastrointestinal tract and the skin Cutaneous flushing lasting 5-10 minutes Involves the head and neck producing a scarlet color Cyanosis may be present Episodic 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 collapse Tumor 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 urine Tx- primary tumor should be removed, and excision of metastatic lesion should be considered Chemotherapy