The association between tumour progression and vascularity in myxofibrosarcoma and myxoid/round cell liposarcoma.

Angiogenesis is an important factor in the morphological progression and metastasis of many solid tumours. We studied two homogeneous series of myxofibrosarcoma (MFS) and myxoid/round liposarcoma (MRLS), characterised by distinct vascular patterns and correlated the intratumoral microvessel density (IMD) with morphologic progression in both types of sarcoma. In our study, 43 cases of MFS and 42 cases of MRLS were graded according to established diagnostic criteria.

Intradermal spindle cell/pleomorphic lipoma: a distinct subset.

Spindle cell/pleomorphic lipomas are a group of benign lipogenic tumors composed of primitive spindle cells, multinucleated giant cells, and mature adipocytes. These tumors have rarely been reported to arise in the dermis and may be misdiagnosed in this location. Twenty (12.

[Lipomatous tumors of the skin and soft tissue. New entities and concepts].

Mesenchymal neoplasms of lipogenic differentiation are the most common soft-tissue neoplasms in adults. In recent years a number of "new" entities and variants have been described. Their recognition is important to avoid diagnostic pitfalls and inappropriate therapy.

[Symplastic hemangioma].

Background And Objective: Endothelial nuclear atypia is the hallmark of malignant vascular tumors. Pleomorphic nuclei of the muscular vessel wall and the adventitia are manifestations of degenerative phenomena and should not be misinterpreted as signs of malignancy.

Patients/methods: Three long-standing solitary superficial vascular tumors (61-year-old woman, 48- and 63-year-old men) were removed by primary excision.

Sclerosing, pseudovascular rhabdomyosarcoma in adults. Clinicopathological and immunohistochemical analysis of three cases.

Rhabdomyosarcoma in adults represents a rare soft tissue neoplasm which is seen most frequently in its pleomorphic subtype in this age group. Very rarely, clear cell and spindle-cell variants have been reported. In this study we describe three cases of rhabdomyosarcoma in adult patients, characterised by prominent hyaline sclerosis and a pseudovascular growth pattern.

Biological continuum of benign, atypical, and malignant mesenchymal neoplasms - does it exist?

The characterization of specific cytogenetic and molecular abnormalities in benign and malignant soft tissue tumours has increased our understanding and knowledge of the biology of these rare neoplasms in recent years and has led to the modification of a number of traditional classification schemes. Contrary to popular belief, it is reasonable to propose that there exists a molecular, genetic, and morphological continuum of benign, atypical, and malignant mesenchymal neoplasms. The identification of characteristic molecular changes in benign lipomas, lipomas with minimal atypia, and atypical lipomatous tumours, well-differentiated liposarcomas supports the hypothesis of a stepwise process in the pathogenesis of these neoplasms.

Intravascular ("intimal") epithelioid angiosarcoma: clinicopathological and immunohistochemical analysis of three cases.

Angiosarcomas are rare malignant mesenchymal tumours, characterized morphologically by anastomosing vascular channels lined by atypical and proliferative active endothelial cells. An epithelioid cytomorphology of tumour cells is often seen focally in angiosarcoma, whereas purely epithelioid angiosarcomas are rare. Although angiosarcomas show a vascular differentiation they are almost never confined to pre-existing blood vessels.

[Chondroid lipoma. Clinicopathological, immunohistochemical, and ultrastructural analysis of six cases of a distinct entity in the spectrum of lipomas].

A series of six cases of chondroid lipoma is reported in this paper. The age of the patients, four women and two men, ranged from 34 to 75 years. Four tumours arose in the lower and two in the upper extremities between 4.

[Tyrosine-rich crystalloids in a myoepithelioma of the minor salivary glands in the smooth palate].

Tyrosine-rich crystalloids in tumors of the salivary glands are rare and have been reported mainly in specimens from Black African patients. The pathogenesis of these structures is still unclear, but pathological secretion by neoplastic myoepithelial cells is supposed. Millon's staining and ultrastructural examinations are used for confirming the diagnosis.

Hobnail hemangioma ("targetoid hemosiderotic hemangioma"): clinicopathologic and immunohistochemical analysis of 62 cases.

Hobnail hemangioma, also known as "targetoid hemosiderotic hemangioma", represents a distinctive, benign vascular tumor, characterized histologically by a biphasic growth pattern of dilated vascular structures in the superficial dermis lined by prominent hobnail endothelial cells, and collagen dissecting, rather narrow neoplastic vessels in deeper parts of the lesion. We analyzed the clinicopathologic and immunohistochemical features in a series of 62 cases. Patient age range was 6-72 years (median: 32 years); 34 patients were male and 25 female.

Intraneural angiosarcoma and angiosarcoma arising in benign and malignant peripheral nerve sheath tumours: clinicopathological and immunohistochemical analysis of four cases.

Aims: Angiosarcomatous differentiation represents the least common form of heterologous differentiation in malignant peripheral nerve sheath tumours (MPNST), and is seen most frequently in patients with neurofibromatosis type 1. More rarely, it has been reported in patients without stigmata of neurofibromatosis, or in benign nerve sheath tumours and peripheral nerves. This study was undertaken to confirm this rare association.

Solitary fibrous tumour of the pancreas: a new member of the small group of mesenchymal pancreatic tumours.

Solitary fibrous tumours usually occur in the pleura, but occasionally they appear in extraserosal soft tissues or parenchymatous organs, where their diagnosis often causes problems. This report describes a solitary fibrous tumour (SFT) of the pancreas in a 50-year-old woman treated by left-side pancreatectomy. The tumour showed immunocytochemical reactivity for CD34, CD99 and bcl-2.

[Extracranial meningioma of the parotid gland].

Extracranial meningiomas of the head and neck region are very rare, although secondary extracranial meningiomas beside meningiomas of primary extracranial origin have also been described. Trauma, radiation and (uncommonly) metastatic spread have been associated with the pathogenesis of secondary extracranial meningiomas. We present a case of a 53-year-old patient who required six neurosurgical interventions because of a recurrent intracranial meningioma.

[Primary synovial sarcoma of the lung].

In the biopsy material of a polypoid intrabronchial lesion of a 54-year-old male patient with radiologically established lung tumor, spindle-cell neoplasia was seen. No clear histogenetic classification of the submucous tumor process was possible. After resection of the right upper lobe of the lung, including the results of additional immunohistochemical analyses, the tumor was classified as biphasic synovial sarcoma.

[Cutaneous neural neoplasms--an update].

Until recently, benign cutaneous neural tumours which do not fulfil criteria for either neurofibrom or schwannoma often were lumped into the broad category of benign peripheral nerve sheath tumours (PNST). However, during the last years a number of new entities of neural tumours have been described, and advances in immunohistochemistry and electronmicroscopy have helped us to better understand the cytological differentiation in these neoplasms. The knowledge of these distinctive neoplasms is necessary in order to avoid diagnostic pitfalls and misdiagnosis of more aggressive neoplasms.

[Cutaneous neural neoplasms--an update].

Until recently, benign cutaneous neural tumours which do not fulfill criteria for either neurofibroma or schwannoma often were lumped into the broad category of benign peripheral nerve sheath tumours (PNST). However, during the last years a number of new entities of neural tumours has been described, and advances in immunohistochemistry and electronmicroscopy have helped us better to understand the cytological differentiation in these neoplasms. The knowledge of these distinctive neoplasms is necessary in order to avoid diagnostic pitfalls and misdiagnosis of more aggressive neoplasms.

[Hemangioendotheliomas--evolution of a concept of a heterogeneous group of vascular neoplasms].

The term haemangioendothelioma has been used in the past for a number of vascular lesions, which vary not only by their morphological features, but more importantly, also by their biological behavior. In the recent WHO-classification of mesenchymal tumours haemangioendotheliomas have been defined as vascular tumours of "intermediate" or "borderline" malignancy, and spindle cell haemangioendothelioma (SHE), epithelioid haemangioendothelioma (EHE), and rare malignant endovascular papillary angioendothelioma (Dabska's tumour) were included in this category. To this list might be added the more recently delineated kaposiform (KHE), retiform (RHE), polymorphous (PHE), and composite haemangioendothelioma (CHE).

[Fibrolipomatous hamartoma of the nerve--a rare etiology of macrodactyly. A case report].

Fibrolipomatous hamartoma of nerve is a rare, tumor-like fibro-fatty growth arising from the epi- and perineurium. It mainly affects peripheral nerves and the median nerve in particular. An association with Klippel-Trenaunay syndrome and macrodactyly has been described.

Low-grade myofibroblastic sarcoma: analysis of 18 cases in the spectrum of myofibroblastic tumors.

The clinicopathologic, immunohistochemical, and ultrastructural features of a seemingly distinctive low-grade spindle cell sarcoma showing myofibroblastic differentiation have been analyzed in a series of 18 patients. The age range of the patients (7 women and 11 men) was 19-72 years (median: 42 years). A painless, enlarging mass was the most common clinical presentation.

Atypical or worrisome features in cellular neurothekeoma: a study of 10 cases.

Cellular neurothekeoma is a recently characterized benign cutaneous neoplasm arising usually on the upper trunk or head and neck of children or young adults. Typical histology is that of a lobulated dermal tumor composed of spindle and epithelioid cells, arranged in fascicles and nests, lacking immunoreactivity for S-100 protein, but usually being NK1/C3 positive. We present 10 new cases of cellular neurothekeoma with atypical histologic features that have not been described previously and that suggested the possibility of malignancy.

Primary liposarcoma of the skin: a rare neoplasm with unusual high grade features.

Liposarcoma is the most common soft tissue sarcoma in adults. It presents in three main forms: well-differentiated liposarcoma (which includes adipocytic, sclerosing, inflammatory, spindle cell, and dedifferentiated subtypes), myxoid/round cell liposarcoma, and pleomorphic liposarcoma. Anatomic distribution depends largely on histologic subtype, but the deep soft tissue of the extremities and the retroperitoneum are most frequently affected.

[Myofibroblastic tumors. Brief review of clinical aspects, diagnosis and differential diagnosis].

This review summarizes myofibroblastic tumours that have been characterized in the last years. These lesions include: fibromatoses in adults and infants (infantile digital fibromatosis and infantile myofibromatosis); myofibroma of adults, an almost exclusively solitary lesion in the skin which is characterized morphologically as a biphasic lesion composed of spindle-shaped eosinophilic tumour cells and more primitive mesenchymal tumour cells associated with a haemangiopericytoma-like vasculature; dermatomyofibroma (plaque-like dermal fibromatosis), a band-like myofibroblastic proliferation in young female patients, which is mainly located in the periaxillar region and in which distinction from more aggressive, plaque-like variant of dermatofibrosarcoma protuberans is mandatory; myofibroblastoma of the breast, a well-circumscribed lesion composed of spindle shaped, desmin-positive tumour cells, which is seen mainly in elderly male patients and has to be distinguished from other spindle cell lesions of the breast; angiomyofibroblastoma, a well-circumscribed myofibroblastic neoplasm of the vulva and vagina composed of avoid to round myoid tumour cells with scattered multinucleated cells, which forms a continuous morphological spectrum with the clinically more aggressive angiomyxoma in this location; intranodal myofibroblastoma, a distinctive proliferation of myofibroblastic cells associated with so-called amianthoid fibres, which is seen most commonly in inguinal lymph nodes; myofibroblastoma/myofibroblastic tumour of soft tissues, a variably well-circumscribed myofibroblastic lesion which lacks atypia and is composed of actin and/or desmin positive tumour cells, and poorly delineated sarcomas with myofibroblastic differentiation (myofibrosarcoma).

Intra-abdominal lymphangioma in a newborn.

We report the case of a male newborn infant with an intra-abdominal cavernous lymphangioma that produced acute abdominal symptoms. Sonography showed a cystic mass with thin septations, which caused intestinal obstruction and stenosis of the iliac artery. The histologic findings after surgical resection reflected the sonographic appearance of the mass.