Biomedical subjects

T Mentzel

Publications and source records attributed to T Mentzel.

At least 37 records · Page 2Linked to original sources

PubMed2001

Cutaneous lipomatous neoplasms.

Benign and malignant lipomatous tumors are the most common neoplasms of subcutaneous and deep soft tissues in adults. In contrast, purely cutaneous lipogenic neoplasms are exceptionally rare, and some entities and variants of adipocytic neoplasms have not yet been described in the skin. In addition, some dermal lipogenic neoplasms are characterized by different specific clinicopathologic features in comparison with more deeply located tumors. Cutaneous angiolipoleiomyoma ("angiomyolipoma") is seen most often in male patients and in an acral location. It is characterized histologically by mature adipocytes, thick-walled blood vessels, and smooth muscle cells arranged in well-defined fascicles and around blood vessels. Smooth muscle cells in cutaneous angiolipoleiomyoma stain negatively for HMB-45, in contrast to renal and extrarenal angiomyolipoma. Adenolipoma of the skin is a superficially located form of lipoma composed of large lobules of mature adipocytic tissue admixed with eccrine ducts and glands. Cutaneous spindle cell/pleomorphic lipomas, in contrast to subcutaneous forms, are more common in female patients and have a wide anatomic distribution. Histologically, cutaneous spindle cell/pleomorphic lipomas are characterized by an infiltrative growth pattern mimicking more aggressive lesions. Rarely, liposarcoma may occur as a purely cutaneous lesion with a favorable clinical prognosis despite high-grade morphologic features in many cases.

Adipocytes↗

PubMed2000

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. Not only are these findings important for our understanding of the biology of soft tissue tumours, but they also may increase diagnostic and prognostic accuracy.

Disease Progression↗

PubMed2000

[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. Sections were stained according to standard histologic and immunohistologic protocols. RESULTS: Symplastic hemangiomas show the silhouette of a small superficial angioleiomyoma or capillary hemangioma. Characteristic features are multinucleate cells of the muscular vessel wall and the adventitia with pleomorphic nuclei, broad hyalinized vessel walls, and the distinctive lack of endothelial nuclear atypia. Recurrences or metastases were not reported (follow-up of 9, 45 and 90 months). CONCLUSIONS: Symplastic hemangioma is a benign superficial hemangioma with histological features of a pseudomalignancy. The distinctive lack of endothelial nuclear atypia allows distinction from malignant vascular tumors.

Angiomyoma↗

PubMed2000

[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. Chondroid lipoma, myolipoma, and purely cutaneous spindle-cell/pleomorphic lipoma are biologically benign neoplasms which may mimic sarcomas morphologically. Despite high-grade morphology cutaneous liposarcomas carry a favorable clinical prognosis. Spindle cell liposarcoma is a rare variant of atypical lipomatous tumour (well-differentiated liposarcoma) and must be distinguished from dedifferentiated liposarcoma with metastatic potential and benign spindle cell lipoma. The advent of cytogenetic and molecular investigations of lipomatous neoplasms has contributed to a better understanding of the biology of these neoplasms and led to a modification of conventional classification schemes.

Diagnosis, Differential↗

PubMed2000

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. All cases were identified in the consultation files of one of the authors and routinely processed. Immunohistochemical studies were performed on paraffin sections with the alkaline phosphatase-antialkaline phosphatase method. The patients, two women and one man, were 40, 41, and 56 years old. One developed a deep-seated soft tissue mass in the left lower leg, and one, a tumour of the left upper jaw. In one patient a bone tumour in the proximal body of the sacrum without extension into soft tissues was seen. The patients were treated by wide excision, piecemeal excision and incomplete excision in one case each; additional radiotherapy was performed in all three cases, and chemotherapy in two patients. In one patient multiple pulmonary metastases were noted, which showed progression despite systemic chemotherapy. Histologically, the neoplasms were composed of round/polygonal and spindle-shaped tumour cells including typical rhabdomyoblasts. In all cases a pseudovascular pattern and prominent hyaline sclerosis of the intercellular matrix was seen. Immunohistochemically, tumour cells stained positively for desmin and muscle actin (HHF35) and also for markers of striated muscle differentiation (myogenin, MyoD1, fast myosin). In this paper an unusual morphological variant of rhabdomyosarcoma arising in adult patients is described, which should be added to the morphological spectrum of these neoplasms.

Adult↗

PubMed2000

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 (12.7%) intradermal lesions identified among 157 spindle cell/pleomorphic lipomas in the authors' files were studied clinicopathologically and immunohistochemically. The patients' ages ranged from 20 to 85 years (median: 42 years); 14 of 20 patients were female (70%). Anatomical sites were the head/neck region (7 cases, 4 of which arose on the face), shoulder/upper back (4 cases), lower limbs (4 cases), trunk (3 cases), and upper limbs (2 cases). Most lesions presented as a soft and slowly enlarging cutaneous nodule, usually measuring less than 2.5 cm. Histologically, these dermal lesions differed from usual spindle cell/pleomorphic lipoma, being unencapsulated with poorly defined infiltrative margins, although the cytomorphologic findings, ropy collagen, and mast cells were as seen in usual subcutaneous lesions. Six cases showed features of pleomorphic lipoma. Immunohistochemically, lesional cells stained positively for CD34 and were negative for S-100 protein. One case recurred locally after 21 years. Dermal spindle cell/pleomorphic lipomas are distinctive in their apparent female predilection, wider anatomical distribution than subcutaneous lesions, and lack of circumscription. These unusual features can cause problems in differential diagnosis.

Adult↗

PubMed1999

[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. Further surgery was required for tumor in the left parotid gland. Histological examination of this neoplasm showed an atypical meningotheliomatous meningioma. The patient is now 17 months after surgery and is free of local recurrences or metastases.

Diagnosis, Differential↗

PubMed1999

[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. These distinctive lesions include: neurothekeoma, which can divided into classical myxoid and cellular types showing characteristic histological and immunohistochemical features. Typical neurothekeoma (nerve sheath myxoma) is a lobular or nodular dermal neoplasm composed of plump spindled or stellated, S-100 positive tumour cells set in a maxoid stroma. In contrast, cellular neurothekeoma is characterized as an ill-defined dermal neoplasm composed of concentric nests and fascicles of spindle-shaped and epithelioid tumour cells, which are S-100 negative but stain positively for NKIC3. The evidence of intermediate forms of neurothekeoma showing features of ordinary hypocellular neurothekeoma and cellular neurothekeoma, as well as ultrastructural studies, emphasize that both variants represent a spectrum of neurothekeoma; solitary circumscribed neuroma ("palisaded encapsulated neuroma") manifests mainly as a skin-colored or pink papule or nodule, and is most often located on the face. Histologically, solitary circumscribed neuroma is a well-circumscribed round or ovoid dermal neoplasm composed of interwoven fascicles of schwann cells, which stain positively for S-100 protein and numerous neurofilament positive axons surrounded partly by fibroblasts and EMA-positive perineural cells; perineurioma is a rare well-circumscribed neoplasm which occurs mainly in subcutaneous tissue and only rarely in the dermis and in deep soft tissues. Perineurioma is composed of elongated bipolar spindle-shaped tumour cells which are arranged in storiform, whorled, linear or lamellated growth patterns, The tumour cells stain positively for vimentin and EMA, and for CD 34 in a number of cases, but lack positivity for S-100 protein, neurofilament and desmoplakin. In addition unusual forms of schwannoma (cellular schwannoma, solitary plexiform schwannoma, melanotic schwannoma) and neurofibroma ("atypical" (bizarre) neurofibroma, diffuse neurofibroma, epithelioid neurofibroma) are briefly discussed.

Humans↗

PubMed1999

[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. This was suggested mostly by immunohistochemical detection of the epithelial membrane antigene (EMA) and of vimentin. Extensive clinical examinations ruled out the possibility of a primary tumor with extrapulmonary localization. This case report shows the problems faced in correctly classifying the histogenesis or the direction of differentiation in extremely rare cases of primary pulmonary synovial sarcoma. Especially in small biopsy samples showing a submucous spindle-cell tumor of the lung, apart from frequent sarcoma metastases, the presence of primary synovial sarcoma of the lung has to be considered in the differential diagnosis.

Antigens, CD↗

PubMed1999

[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. We present the case report of a 59-year-old woman with a myoepithelioma of the minor salivary glands in the smooth palate containing tyrosine-rich crystalloids as an example of this rare phenomenon.

Black People↗

PubMed1999

[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 4.5 and 8 cm in size. Whereas two neoplasms were located in the subcutis, four lesions were seen in perifascial or intramuscular tissues. Histologically, all neoplasms were encapsulated and characterized by a somewhat lobular growth pattern. The neoplasms were composed of mature adipocytes, uni - and multivacuolated lipoblasts, and nests and strands of cells reminiscent to hibernoma cells or chondrocytes. Immunohistochemically and ultrastructurally the lipogenic nature of the latter type of cells was confirmed. Interestingly, focal immunopositivity of tumour cells for cytokeratin was found in two cases. Tumour cells were set in a myxohyaline matrix showing different degrees of degeneration. Chondroid lipoma represents a distinct entity in the spectrum of lipomatous lesions and has to be distinguished from benign and malignant neoplasms (extraskeletal chondroma, hibernoma, lipoblastoma, chondrolipoangioma, myoepithelioma, myxoid/round cell liposarcoma, and extraskeletal myxoid chondrosarcoma). Because they are easily misdiagnosed as malignant tumours, familiarity with the features of chondroid lipoma is of practical importance to avoid an overtreatment.

Adipose Tissue↗

PubMed1999

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. Because of its favourable prognosis, SFT must be clearly distinguished from leiomyosarcoma, the most frequent nonepithelial tumour of the pancreas. Other mesenchymal tumours that may occur in the pancreas include tumours of the peripheral nerve sheath, fibrous histiocytic tumours and rare vascular tumours.

12E7 Antigen↗

PubMed1999

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. We describe three cases of intravascular epithelioid angiosarcoma arising in the carotid artery of a 60-year-old man, in the infrarenal part of the abdominal aorta and both renal arteries of a 69-year-old woman, and in the abdominal aorta of a 68-year-old man. In all cases malignant tumour tissue was found incidentally after disobliteration of thrombosed vessels. Histologically, purely epithelioid angiosarcoma composed of solid sheets of epithelioid tumour cells was seen; immunohistochemistry confirmed the endothelial differentiation of neoplastic cells. The reported cases show that angiosarcoma can occasionally arise within a pre-existing vessel.

Aged↗

PubMed1999

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. METHODS AND RESULTS: Four cases of angiosarcoma arising in a peripheral nerve, in a long-standing schwannoma and in two MPNST are described. Immunohistochemical studies were performed on paraffin sections with the alkaline phosphatase-antialkaline phosphatase method. An intraneural high-grade epithelioid angiosarcoma arose in the left posterior tibial nerve of a 78-year-old man, a well to moderately differentiated angiosarcoma was seen in an ancient schwannoma of the lateral neck in a 73-year-old women, and an angiosarcoma of varying grades of differentiation developed in a recurrent MPNST in the thigh of 38-year-old man. In addition a high-grade MPNST in the axillary region of a 30-year-old man showed foci of heterologous high-grade angiosarcomatous differentiation. The neural and endothelial lines of differentiation were confirmed in each case by positive immunohistochemical staining for neural and endothelial markers, respectively. In all cases tested, the neural differentiated cells stained immunohistochemically positive for antibodies against vascular endothelial growth factor. CONCLUSIONS: This study confirms the rare association of angiosarcoma arising in peripheral nerves, as well as in benign and malignant peripheral nerve sheath tumours.

Adult↗

PubMed1999

[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. We present a 30-year-old patient, in whom the diagnosis of Klippel-Trenaunay syndrome had been made at the age of two, based on macrodactyly of the right hand. Because of increasing functional limitation and pain, the patient was referred to our department, after angiographic exclusion of Klippel-Trenaunay syndrome, for operative reduction of the tumor. Histologic examination revealed a fibrolipomatous hamartoma of the nerve. Further treatment consisted of surgical tumor reduction, which resulted in satisfactory recovery of function in the right hand. After eight months follow-up, the patient was able to perform all normal daily activities, and there was no evidence of recurrence of the lesion. Diagnostic evaluation of macrodactyly is necessary, since there may be an underlying cause such as fibrolipomatous hamartoma of a nerve, which if corrected early by surgical excision may prevent long-term disability.

Adult↗

PubMed1999

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. Clinically, a broad variation of diagnoses ranging from hemangioma to dermal melanocytic nevus and fibrous histiocytoma was suggested. Nineteen tumors arose in the lower and 13 in the upper extremities, 12 on the back, 8 in the buttock and hip region, and one case on the chest wall. Follow-up information on 35 patients (range from 1 to 4 years; mean: 1.5 years) revealed no local recurrence nor systemic metastasis. All neoplasms were located in the dermis and showed a broad morphologic spectrum in dependence of the age of the lesions. In addition to lesions resembling cavernous lymphangioma or lymphangioma circumscriptum, neoplasms were seen with morphologic features reminiscent to retiform hemangioendothelioma, progressive lymphangioma and so-called Dabska's tumor. Immunohistochemistry performed in 28 cases showed positive staining of tumor cells for CD31 in all cases tested, whereas only 3 out of 28 cases stained completely positive for CD34. In addition 4 out of 8 cases stained positively for vascular endothelial growth factor receptor-3 (VEGFR-3). Neoplastic endothelial cells were surrounded by actin-positive pericytes in only 7 out of 27 cases tested. Hobnail hemangioma occurs more frequently in male patients and arises commonly in the extremities and the trunk. Histologic and immunohistochemcial features suggest a lymphatic line of differentiation for this distinctive vascular neoplasm.

Adolescent↗

PubMed1998

[Primary primitive neuroectodermal tumor of the urinary bladder. Clinicopathologic case report and differential small cell tumor diagnosis of this site].

We report a rare case of primary primitive neuroectodermal tumour of the bladder in an adult. A huge tumour with extensions into pelvic and retroperitoneal tissue was found radiologically in a 62-year-old man. The patient did not complain about remarkable clinical symptoms until 4 days before admission to hospital. Histology of diagnostic transurethral tumour resection showed a small round-cell tumour with focal necrosis and scattered Homer-Wright rosettes. Immunohistochemical analysis revealed that tumour cells stained positively with 013, a monoclonal antibody which recognizes the membrane glycoprotein p30/32MIC2. Focally, tumour cells stained positively for vimentin, NSE, S-100 protein and synaptophysin. The patient died 3 weeks later because of fulminant pulmonary embolism and autopsy revealed a huge, partly exophytic but mainly endophytic tumour of the bladder with extensions into the rectum and retroperitoneal tissue. The differential diagnosis of small round-cell tumours in this location is discussed.

Adult↗

PubMed1998

[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).

Adult↗