1/8. Primary cutaneous sarcomas showing rhabdomyoblastic differentiation.rhabdomyosarcoma is a rare soft tissue neoplasm most commonly encountered in childhood and adolescence which has a predilection for the head and neck area, the genito-urinary tract and the extremities. Primary cutaneous presentation is extremely unusual and has been rarely reported in the literature. Herein, we describe two cases of rhabdomyosarcoma arising in the dermis of a 9-year-old girl and an 86-year-old man. Clinically, the tumours presented as solitary plaque-like or nodular lesions confined to the skin of the nose and chest wall, respectively. Histologically, the tumour in the first patient corresponded to an embryonal rhabdomyosarcoma. The tumour recurred locally four times, and in the last recurrence, showed features resembling those of malignant 'triton' tumour with fascicles of S-100 protein-positive spindle cells admixed with the rhabdomyoblastic components. The tumour in the second patient corresponded to the solid variant of alveolar rhabdomyosarcoma. Immunohistochemical studies in both tumours showed positive labelling for muscle-specific actin, desmin and vimentin. Ultrastructural examination in one case showed clusters of intermediate filaments in the cytoplasm recapitulating abortive sarcomeric structures consistent with rhabdomyoblastic differentiation. Both patients developed repeated recurrences over a period of 2-4 years despite adequate surgical excision, and the second patient had an axillary lymph node metastasis. Primary cutaneous rhabdomyosarcoma should be considered in the evaluation of small 'blue cell' tumours or undifferentiated malignant neoplasms of the skin, and appropriate immunohistochemical studies in conjunction with electron microscopy should be employed for proper evaluation of such lesions.- - - - - - - - - - ranking = 1keywords = dermis (Clic here for more details about this article) |
2/8. Malignant epithelioid schwannoma of the skin showing partial HMB-45 positivity.A malignant epithelioid schwannoma occurred on the right second toe of a 30-year-old Japanese man. It was a firm, flesh-colored, benign-appearing nodule and measured 13 x 9 mm in diameter and 6 mm in height. To our knowledge, this is the first case of malignant epithelioid schwannoma occurring on the toe. Histopathology was characterized by a circumscribed nodule in the dermis that predominantly consisted of atypical large epithelioid cells with some spindle cells whose proliferation was similar to that of the Verocay bodies seen in ordinary schwannoma. Fontana-Masson staining demonstrated no melanin pigment in the tumor at the light microscopic level. The eosinophilic cytoplasm contained abundant glycogen and was positive for S-100 protein and HMB-45, as usually seen in melanomas. Electron microscopy revealed that there was an abundance of long-spacing collagen in the extracellular matrix, and the cells contained numerous dense-cored granules. But no definite melanosomes were observed in any stage. As far as we are aware, this is the first case of a malignant epithelioid schwannoma showing HMB-45 positivity.- - - - - - - - - - ranking = 1keywords = dermis (Clic here for more details about this article) |
3/8. Malignant schwannoma with melanocytic and neuroepithelial differentiation in an infant with congenital giant melanocytic nevus: a complex neurocristopathy.We describe an infant girl, born with a pigmented giant nevus, who developed a malignant schwannoma in the retroperitoneum at 16 months of age. At birth the nevus covered over 50% of her body and histologically was a compound nevus with extension into the deep dermis surrounding dermal appendages. The malignant schwannoma was biphasic with areas composed of spindle and round cells. Ultrastructurally, the majority of the tumor cells exhibited a Schwann cell phenotype, but neuroepithelial and melanocytic cells were identified as well. We believe that this constellation of findings represents a form of neurocristopathy. Neurocristopathy, as defined by Bolande (Hum Pathol 5:409-429, 1974), is a disease that results from aberrations in the migration, growth, or cytodifferentiation of neural crest tissues. These diseases may be simple (a singular pathologic process, usually localized) or complex (multiple neuroectodermal lesions). We report this case because the occurrence of retroperitoneal malignant schwannoma arising in a 16-month-old infant born with a pigmented giant nevus is unique, and may represent a previously undescribed form of a complex neurocristopathy.- - - - - - - - - - ranking = 1keywords = dermis (Clic here for more details about this article) |
4/8. Lymphocytic meningitis following insertion of a porcine dermis dural graft.We describe a case of lymphocytic meningitis following insertion of a porcine dermis implant to repair an operative dural defect. histology of the excised implant revealed local abscess formation with a granulomatous reaction. Oligoclonal immunoglobulin g, part of which could be removed by absorbtion with the porcine dermis, was present in the patient's cerebrospinal fluid, and, to a less marked degree, in his serum. The cerebrospinal fluid glucose was markedly depressed. An unusual hypersensitivity reaction to the porcine implant was considered the most likely explanation for this meningitic illness. The patient went on to make a full recovery following excision of the implant.- - - - - - - - - - ranking = 6keywords = dermis (Clic here for more details about this article) |
5/8. Multiple cutaneous plexiform schwannomas. Report of a case and review of the literature with particular reference to the association with types 1 and 2 neurofibromatosis and schwannomatosis.Plexiform schwannomas are relatively rare, benign peripheral nerve sheath tumors, which usually arise in either the dermis or subcutaneous tissue, although rare cases originate in skeletal muscle or other deep somatic soft tissue sites. These tumors may occur singly or as multiple lesions and may be localized to one anatomic site or diffusely distributed. Rare cases have been associated with "schwannomatosis" as well as type 1 neurofibromatosis (von Recklinghausen's disease). We report an unusual case of multiple cutaneous plexiform schwannomas associated with bilateral acoustic neuromas as well as other intracranial and intraspinal neoplasms. In addition, we examine the relationship between the various forms of cutaneous schwannoma, particularly the plexiform variant, and both types 1 and 2 neurofibromatosis; we also examine several purported cases of schwannomatosis.- - - - - - - - - - ranking = 1keywords = dermis (Clic here for more details about this article) |
6/8. Cutaneous plexiform schwannoma associated with neurofibromatosis type 2.BACKGROUND. Plexiform schwannoma (PS) is a rare benign tumor of the nerve sheath that can be located either in the deep soft tissues or in the dermis or subcutis. The tumor predominantly affects young adults and occurs most commonly as a slowly growing asymptomatic solitary nodule in the head and neck region, trunk, and upper extremities. methods. A cutaneous PS located in the preauricular region of a 19-year-old white female is reported. The patient exhibited six "cafe-au-lait" spots in the trunk and the extremities. magnetic resonance imaging examination showed bilateral tumors in both acoustic nerves (considered schwannomas) and also masses in the right major sphenoidal wing, falx, and T2-T3 level of rachis and a solid and cystic tumor in the low medulla oblongata. Tumors of the preauricular region, medulla oblongata, spinal cord at level T2-T3, and major sphenoidal wing area were surgically removed. The tumors were studied by immunohistochemistry and diagnosed as PS, pilocytic astrocytoma, and meningiomas, respectively. RESULTS. Seventy-eight cases of PS have been reported in the literature: 8 (10.2%) have been associated with clinical schwannomatosis, 6 (7.7%) with multiple cutaneous schwannomas syndrome, and only 3 (3.8%) with neurofibromatosis type 1 (NF-1). CONCLUSIONS. In this report, to the authors' knowledge, for the first time PS is described associated with neurofibromatosis type 2. The tumor does not appear to have significant association with NF-1. Plexiform schwannoma should be recognized because it may be misdiagnosed as plexiform neurofibroma or other plexiform malignant tumors. Differentiation from plexiform neurofibroma is important, because the latter is virtually pathognomonic of neurofibromatosis type 1 and has a propensity for malignant transformation.- - - - - - - - - - ranking = 1keywords = dermis (Clic here for more details about this article) |
7/8. Idiopathic solitary neuroma of skin with unusual histologic changes.We report herein a case of idiopathic solitary neuroma with vascular proliferation and neurofibroma-like features. Clinically, the skin lesion was a 0.7 cm nodule without tenderness on the forearm. Histologically, there was vascular proliferation in the upper dermis, some neural structures among the proliferative vasculature in the mid dermis and large bundles of neural structures extending in various directions in the mid and deep dermis (resembling neurofibroma). Special stains, such as Masson's trichrome and Luxol fast blue, and immunohistochemical studies, including S-100 protein, neuron-specific enolase (NSE), vimentin, desmin, factor-VIII related antigen and epithelial membrane antigen (EMA), were added for this very rare case.- - - - - - - - - - ranking = 3keywords = dermis (Clic here for more details about this article) |
8/8. Pleomorphic hyalinizing angiectatic tumor of soft parts: immunohistochemical case study shows cellular composition by CD34 fibroblasts and factor xiiia dendrophages.We report immunomorphologic observations on a pleomorphic hyalinizing angiectatic tumor of soft parts (PHAT), a rare tumor recently described by Smith, Fisher, and Weiss. A 2 cm skin-covered, grossly lobulated, firm, yellow-tan, focally hemorrhagic tumor was excised from the dorsum of a 59-year-old woman's right foot. It infiltrated dermis and subcutis and entrapped skin adnexae. The tumor microscopically resembled both a pleomorphic malignant fibrous histiocytoma and a neurilemoma with fascicular spindle cell pattern, pleomorphic tumor giant cells, and focal congeries of ectatic, fibrinous, and slightly hyalinized vessels. Tumour cells produced abundant reticulin but collagenous sclerosis was minimal. mast cells were numerous. Pleomorphic cells, some phagocytic, had intranuclear vacuolar inclusions and many cells had large pale cytoplasmic globular inclusions. Most tumor cells expressed vimentin and CD34, including pleomorphic cells. factor xiiia stained focally 20-40% of the spindle cells. S-100 and cytokeratin were negative and actin and desmin stained only vessel myopericytes. The Ki 67 index was 3% with mostly large CD34 cells and a few smaller FXIIIa cells in the cycling fraction. We conclude that PHAT is a fibrohistiocytic tumor probably derived from proliferating microvascular CD34 dendritic cells and FXIIIa dendrophage cell subsets. Possible interactions between these cell types deserve further study in PHAT and other fibrohistiocytic tumors.- - - - - - - - - - ranking = 1keywords = dermis (Clic here for more details about this article) |