Dermal and Subcutaneous Tumors

1. Dermal and Subcutaneous Tumors

2. Mastocytosisurticaria 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

3. 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

4. Urticaria pigmentosa

6. 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

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

10. 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

11. 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

12. Abnormalities of neural tissue

13. 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

14. 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

16. 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

17. 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

19. 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

20. Occur in many other organs • excision

21. 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

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

24. 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

26. 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

27. 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

28. 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

29. Abnormalities of Fat Tissue

30. 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

32. 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

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

35. 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

36. 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

37. 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

38. 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

39. 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

40. Nevus lipomatosus superficialis

42. 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

44. 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

45. 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

46. 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`

47. 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

48. 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

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