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T Mentzel

Publications and source records attributed to T Mentzel.

At least 91 records · Page 5Linked to original sources
PubMed1995

Pseudomalignant perineurial invasion in cellular ('infantile') capillary haemangiomas.

One hundred and sixty-eight cellular ('infantile') capillary haemangiomas were assessed for the presence of perineurial invasion, a feature that can lead to the erroneous diagnosis of malignancy. Fourteen tumours (8%) showed unequivocal, usually prominent, involvement of small and medium sized nerves. Eleven of these lesions presented in infants at birth or shortly thereafter, two in young adults and one in a middle-aged adult. Ten patients were females. Ten of the lesions arose in the head and neck region, one in the arm, one in the chest wall, and in two the site was not stated. Follow-up revealed a local recurrence in only one of six cases. Histologically, all cases were typical pure capillary haemangiomas composed of lobules of small blood vessels, lined by bland endothelial cells, involving the dermis, subcutis or both. One case was an intramuscular capillary haemangioma. Long-standing cases, especially those in adults, were less cellular, with focal fibrosis and a myxoid stroma. Neural invasion was detected either in the centre or at the periphery of tumour lobules and was characterized by the presence of variable numbers of capillaries within the perineurium and in close contact with Schwann cells. This feature was highlighted by immunostaining for S-100 protein and EMA. In one case, extensive invasion of medium-sized deep dermal veins was also present, focally simulating an intravascular pyogenic granuloma. This study demonstrates that perineurial invasion in infantile capillary haemangiomas is a relatively common finding and should not be regarded as evidence of malignancy.

Adolescent↗
PubMed1995

Low grade fibromyxoid sarcoma: clinicopathological analysis of eleven new cases in support of a distinct entity.

Low grade fibromyxoid sarcoma is a recently recognized, uncommon soft tissue neoplasm with a tendency to develop in deep soft tissue of young adults. Diagnostic criteria have not been well defined and this tumour has not been widely accepted as a distinct entity. Eleven new cases are reported here for which reproducible histological features are described and in which the immunohistochemical profile of the tumour cells is documented for the first time. Ten of the eleven patients were male and the majority were young or middle-aged adults (median age 45 years). All except one of the tumours were situated in deep soft tissue. Lower limb (four cases) and chest wall (three cases) were the commonest primary sites; one case each arose in the groin, buttock, axilla and retroperitoneum. Follow-up (median duration 6 years) was available in nine patients. Six developed local recurrence and in five cases recurrences were multiple. Pulmonary metastasis occurred in one patient. All tumours were characterized by the presence of bland spindle cells, showing a mainly whorled or focally linear arrangement, set in alternating areas with a fibrous or myxoid stroma. Tumour cells were small, spindle to stellate, with poorly defined, palely eosinophilic cytoplasm and hyperchromatic ovoid nuclei. Most tumour cells showed strong staining with antibodies to vimentin, while occasional cells stained positively for actin, desmin and cytokeratin, in keeping with focal myofibroblastic differentiation. Ultrastructural examination in one case revealed features of fibroblasts. Careful consideration of the morphological and immunohistochemical features of these tumours permits a positive diagnosis of low grade fibromyxoid sarcoma and allows its distinction from a number of other benign and malignant soft tissue neoplasms.

Adolescent↗
PubMed1994

Malignant mesenchymomas of soft tissue associated with numerous osteoclast-like giant cells mimicking the so-called giant cell variant of "malignant fibrous histiocytoma".

Three cases of malignant mesenchymoma with numerous osteoclast-like giant cells, arising in deep soft tissue, and which mimicked the so-called giant cell variant of "malignant fibrous histiocytoma" have been studied. All three neoplasms arose in adults; two patients were male and one was female. Two tumours arose in the thigh, and one in the right shoulder. Two patients died within 2 years of the primary excision while the third is alive and well at 2.5 years. Histologically, one case showed leiomyosarcoma plus liposarcoma, one leiomyosarcoma plus osteosarcoma, and one tumour consisted of liposarcoma plus osteosarcoma; all components were assessed morphologically as high-grade malignant. All three cases showed prominent osteoclast-like giant cells in the leiomyosarcomatous or osteosarcomatous areas, thereby closely mimicking the phenotype of so-called giant cell variant of "malignant fibrous histiocytoma". We discuss briefly differences in soft tissue sarcomas demonstrating this distinctive osteoclast-rich phenotype.

Adult↗
PubMed1994

[Primary primitive neuroectodermal tumor of the kidney in an adult. Clinico-pathologic and immunohistochemical case report].

We report a case of a primary renal primitive neuroectodermal tumour in a 24-year-old man associated with multiple pulmonary metastases. Histologically, the bulk of the kidney was replaced by a small round-cell tumour with numerous true Homer-Wright rosettes and perivascular pseudorosettes; wide-spread vascular invasion was noted. There was no evidence at autopsy of a primary tumour elsewhere. Immunohistochemically, the tumour cells stained strongly positive for O-13, a monoclonal antibody, which recognizes a recently described cell membrane glycoprotein (p30/32MIC2), more weakly for NSE and at least focally for PGP 9.5; the tumour did not stain for other neural markers, cytokeratin, leucocyte common antigen, or desmin. The differential diagnosis of small round-cell tumours in this location and the relation of primitive neuroectodermal tumours and Ewing's sarcoma are discussed.

Adult↗
PubMed1994

[Vascular tumors of the skin and soft tissue. Overview of newly characterized entities and variants].

This review summarizes vascular tumours of skin and soft tissues that have been characterised in recent years. Although most of them are very rare, knowledge about their reproducible clinicopathological features is important to avoid diagnostic pitfalls. These lesions include: bacillary angiomatosis, a vasoproliferative, pseudoneoplastic infection of immunocompromised patients caused by Rochalimaea henselae; tufted angioma, a variant of lobular capillary haemangioma characterised by a "cannon-ball" distribution of multiple lobules composed of packed capillaries and pericytes; microvenular haemangioma, a cutaneous haemangioma composed of thin-walled and irregularly branching blood vessels which dissect dermal collagen; sinusoidal haemangioma, a distinctive variant of cavernous haemangioma which may be located in the subcutaneous breast tissue and then may be confused with well-differentiated angiosarcoma; "hobnail haemangioma" (targetoid haemosiderotic haemangioma), a benign vascular tumour with a distinctive clinical targetoid appearance and a hobnail cytomorphology of the prominent endothelial tumour cells; retiform haemangioendothelioma, a very recently characterised low-grade angiosarcoma occurring most commonly in the extremities of adolescents which is characterised by arborising blood vessels arranged in a retiform pattern and lined by hobnail-like prominent endothelial cells; Kaposi-like infantile haemangioendothelioma, a borderline malignant tumour of infants mimicking Kaposi's sarcoma histologically; epithelioid angiosarcoma, a highly aggressive tumour in the spectrum of epithelioid vascular lesions which stains positively for endothelial and epithelial immunohistological markers; benign lymph-angioendothelioma (progressive lymphangioma), a benign, slowly growing macule or plaque which has to be distinguished from well-differentiated angiosarcoma and Kaposi's sarcoma; and lymphangiomatosis of the limbs, a poorly recognised angiomatosis occurring in young patients and limited mainly to the limbs with a favourable prognosis.

Connective Tissue↗
PubMed1994

Leiomyoma of deep soft tissue. Clinicopathologic analysis of a series.

Leiomyomas of deep soft tissue are extremely rare and, to our knowledge, have never been adequately characterized either histologically or clinically. We report 11 such cases, most often arising in deep subcutis or skeletal muscle. The lesions were equally distributed among males (six cases) and females (five cases); age at presentation ranged from 14 to 62 years (mean, 37 years; median, 35 years). The extremities represented the single most common site (five cases). Characteristic morphologic features included well-defined circumscription with a fibrous pseudocapsule, myxohyaline stromal degeneration, and intersecting fascicles of spindle cells with mostly uniform, round-ended, elongated nuclei and tapering, eosinophilic cytoplasm. Dystrophic calcification was identified in four cases; degenerative nuclear changes, similar to those in ancient schwannoma, were present in three cases. Two neoplasms showed multiple necrobiotic granuloma-like nodules resembling giant rosettes. Mitotic figures were found in only four cases and were scarce, never exceeding one mitotic figure per 50 high-power fields. Immunohistochemically, all cases showed desmin positivity. Clinical follow-up (median, 4.5 years), available for nine cases, revealed no evidence of local recurrence or distant metastasis. As with all smooth-muscle cell neoplasms, meticulous attention to the presence of significant mitotic activity and suppurative tumor necrosis is essential because they suggest potential malignant behavior.

Adolescent↗
PubMed1994

Spindle cell liposarcoma, a hitherto unrecognized variant of liposarcoma. Analysis of six cases.

A series of six cases of a previously unrecognized variant of liposarcoma characterized by a prominent spindle cell component is reported herein. Clinically, all of the tumors arose in adults and developed around the shoulder girdle or upper limbs; all but one arose in subcutaneous tissue. Three patients developed multiple local recurrences over a period of 4-20 years. Recurrences in one case were purely lipoma-like. Following dedifferentiation in a recurrence, one patient developed distant metastases and eventually died, 46 months after the primary excision. Grossly, these lesions are characterized by multinodularity, and microscopically they show a relatively bland spindle cell proliferation arranged in fascicles and whorls and set in a variably myxoid stroma. The spindle cell areas are accompanied by an adipocytic component, which exhibits the morphologic features required for inclusion in the well-differentiated liposarcoma-atypical lipoma group, including definite lipoblasts. Main differential diagnoses include benign lesions such as spindle cell lipoma and diffuse neurofibroma, as well as dermatofibrosarcoma protuberans and other malignancies such as sclerosing liposarcoma, low-grade myxofibrosarcoma, low-grade malignant peripheral nerve sheath tumor, and low-grade fibromyxoid sarcoma. In view of their distinctive histologic appearance, and because aggressive clinical behavior was observed despite their superficial location, we propose that these lesions be regarded as spindle cell variants of well-differentiated liposarcoma.

Adult↗
PubMed1994

Infantile hemangiopericytoma versus infantile myofibromatosis. Study of a series suggesting a continuous spectrum of infantile myofibroblastic lesions.

The clinicopathologic features of 11 tumors, originally diagnosed as infantile hemangiopericytomas and with a spectrum of morphologic findings, are described. The age of the patients ranged from 6 days to 7 years; seven patients were younger than 1 year (mean, 2.25 years; median, 10 months); six were boys and five were girls. Three neoplasms were situated in skin or subcutis and seven in deep soft tissue; in one case the depth was unstated. Seven lesions arose in the lower limbs, and one each in the lumbar region, clitoris, chest wall, and soft tissue of the zygomatic region. One patient later was found to have two additional dermal tumors, one each on the anterior abdominal wall and the chest wall. Follow-up information in eight patients revealed local recurrence 12 years later in one case only. Histologically, all tumors showed distinctive features of infantile hemangiopericytoma, including immature cytology, multilobulated growth pattern, focal necrosis, and mitotic activity in varying degrees. Vascular invasion was noted in seven cases. Additionally, a second tumor cell component, composed of spindle-shaped myofibroblastic cells forming fascicles and micronodules, was evident at least focally. Both the spindle cells and more primitive round cells were positive for alpha-smooth muscle actin. Both cellular components showed a haphazard zoning arrangement. We discuss the clinicopathologic similarities between infantile hemangiopericytoma and infantile myofibromatosis and point out the differences between infantile and adult hemangiopericytoma. Our study suggests that there exists a broad spectrum of benign infantile myofibroblastic lesions containing an immature-appearing cellular component with a distinctive, hemangiopericytoma-like vascular pattern. Infantile myofibromatosis and so-called infantile hemangiopericytoma almost certainly represent different stages of maturation of the same (single) entity.

Child↗
PubMed1994

Dedifferentiated liposarcoma. Clinicopathologic analysis of 32 cases suggesting a better prognostic subgroup among pleomorphic sarcomas.

Dedifferentiated liposarcoma is uncommon, and only a small number of cases have been documented. We describe the clinicopathologic features in a series of 32 cases. All patients were adults (age range, 37-83 years; median, 67 years); 20 were men and 12 were women. Commonest site was the retroperitoneum (fifteen cases); six cases arose in the limbs, four in the paratesticular region, three in the peritoneal cavity, two on the trunk, and one each in the buttock and larynx. One primary tumor was subcutaneous. Thirty tumors arose de novo (i.e., combined with well-differentiated tumor in the primary lesion), while two developed in recurrences of a previously well-differentiated liposarcoma. The well-differentiated component was most often lipoma-like and typically there was a histologically abrupt transition to spindle celled nonlipogenic tumor. The dedifferentiated component most often resembled either storiform "malignant fibrous histiocytoma" ("MFH") with limited pleomorphism or myxofibrosarcoma (myxoid "MFH"); the latter pattern is rarely otherwise seen in the retroperitoneum. A small number of cases showed appearances reminiscent of myxoid embryonal rhabdomyosarcoma. An unusual feature in three cases was the occurrence of a discontinuous micronodular pattern of dedifferentiation. Average follow-up of 5.6 years (range, 3 months to 33 years) in 27 cases have revealed local recurrence in 14 patients and systemic metastases in only four patients. The primary sites of the metastasising cases were upper back, thigh, retroperitoneum, and paratesticular region. There have been only seven tumor-related deaths. Good prognosis in de novo dedifferentiated liposarcomas seems unrelated to the extent or morphologic pattern of dedifferentiation. However, high mitotic activity in the dedifferentiated component was associated with a more aggressive clinical course. Our study underlines that dedifferentiation in peripherally located or even subcutaneous liposarcomas does occur, albeit rarely, and that dedifferentiated liposarcomas of the limbs may metastasize. The results suggest that dedifferentiated liposarcomas, as a subgroup among the "MFH-like" sarcomas, have a better prognosis than pleomorphic sarcomas as a whole.

Adult↗
PubMed1994

Granular cell change in smooth muscle tumours of skin and soft tissue.

Nine smooth muscle tumours, arising at a variety of sites and showing granular cell change of their cytoplasm, have been studied morphologically and immunohistochemically. The age of the patients ranged from 6 to 78 years (median 42 years); seven patients were female. Two tumours each arose in the dermis or subcutaneous tissue while the other five cases were situated in deeper soft tissue. Three of the lesions arose in the lower limbs, two in the pelvis and one each in the regions of the elbow, shoulder, breast and buttock. Follow-up in eight patients was available and revealed local recurrence in three and pulmonary metastases in two cases. All cases showed at least focally the light microscopic features of a smooth muscle tumour and demonstrated moderate to strong positivity for alpha-smooth muscle actin. Five were also HHF-35 positive and three were desmin positive. Noteworthy was strong positivity for the 'melanoma associated' antigen NKI/C3 in all cases. Six cases stained also weakly positive for NSE, but all were S-100 protein negative. The former is not specific but is the most reliable marker of lesions showing granular cell change. Granular cytoplasmic change represents simply a cytological phenotype, apparently representing a characteristic metabolic alteration, not exclusively associated with Schwann cell tumours. Tumours containing granular cells are best classified according to their line of specific cellular differentiation if possible.

Actins↗
PubMed1994

Perineurioma (storiform perineurial fibroma): clinico-pathological analysis of four cases.

Four cases of perineurioma (storiform perineurial fibroma) arising in the dermis, subcutis, or deep soft tissue have been studied. Two patients were female and two were male with ages ranging from 19 to 45 years. One lesion each arose on the chest wall, shoulder, neck, and elbow. Follow-up information in three patients revealed no recurrence. Histologically, the neoplasms were circumscribed but non-encapsulated lesions and were composed of spindle cells with elongated bipolar cytoplasmic processes, inconspicuous fusiform nuclei and well-defined palely eosinophilic cytoplasm. These cells were arranged in whorls or lamellar-like structures and often demonstrated a storiform growth pattern. In areas, the tumour cells appeared larger with more rounded nuclei. Immunohistochemically, most of the tumour cells stained positive for epithelial membrane antigen and vimentin, but failed to stain for S-100 protein, neurofilament, desmoplakin, and CD34. Ultrastructurally, two cases showed fusiform tumour cells with long, thin cell processes separated by abundant collagen bundles. Tumour cells were covered by discontinuous external lamina, showed many pinocytic vesicles and occasionally desmosome-like structures. The morphology and EMA immunopositivity of perineurioma are similar to meningioma, especially to cutaneous meningioma type II. We believe that perineurioma and meningioma are closely related, but morphologically distinguishable, neoplasms.

Adult↗
PubMed1994

Cellular benign fibrous histiocytoma. Clinicopathologic analysis of 74 cases of a distinctive variant of cutaneous fibrous histiocytoma with frequent recurrence.

We report seventy-four cases of a distinctive variant of cutaneous fibrous histiocytoma, which is often mistaken histologically for sarcoma and which carries a high local recurrence rate. These tumors appeared most commonly in young or middle-aged adults, with a predominance in men (male/female ratio 1.9:1). Anatomic distribution was wide, with cases occurring mainly in the upper limb/limb girdle (34%), lower limb/limb girdle (27%), and head and neck region (20%). Most lesions had been present for only a few months, and their sizes ranged from 0.5 cm to 2.5 cm in maximum diameter. Twelve (26%) of 46 cases with follow-up (mean duration 3 years) recurred locally, in one case twice. Distinctive histologic features were a commonly fascicular growth pattern, predominance of eosinophilic spindle cells with tapering nuclei, a moderate mitotic rate (mean three per 10 high-power fields), and frequent extension into the subcutaneous fat (33% of cases). In addition, all cases showed at least focal cytologic polymorphism (inflammatory cells, foam cells, giant cells), and 58% showed associated epidermal alterations in common with usual cutaneous fibrous histiocytomas. Nine cases (12%) showed foci of central necrosis. Immunohistochemical studies (ABC method) found only vimentin and very focal smooth muscle actin positivity. Tests for CD34, desmin, S-100, keratin, and Factor XIIIa were negative in all cases. These lesions should be distinguished from dermatofibrosarcoma protuberans and leiomyosarcoma, with which many of these cases were initially confused.

Adolescent↗
PubMed1994

Leiomyosarcoma with prominent osteoclast-like giant cells. Analysis of eight cases closely mimicking the so-called giant cell variant of malignant fibrous histiocytoma.

Eight cases of leiomyosarcoma with osteoclast-like giant cells, arising in deep soft tissue, and that mimicked closely the "giant cell variant of malignant fibrous histiocytoma (MFH)," have been studied morphologically and immunohistochemically. The age of the patients ranged from 7 to 88 years (mean, 66.2 years; median, 74 years); five were female patients. Three lesions arose in the lower limbs, two in the buttock, and one each in the shoulder, chest wall, and the floor of the mouth. Follow-up in one case revealed a local recurrence and in two cases systemic metastases. All cases showed, at least focally, interwoven spindle cell fascicles, with the cytologic features of smooth muscle cells, as well as strong positivity for alpha-smooth-muscle actin, muscle actin, and desmin. The morphologically benign osteoclast-like giant cells expressed CD68 but failed to stain with myogenic markers. The association of leiomyosarcoma with prominent osteoclast-like giant cells is not as uncommon as generally believed, being evident in 8.7% of the deep-seated nonvisceral leiomyosarcomas that we have studied. These results provide good evidence for myogenic differentiation in at least a subset of those tumors with morphologic features currently classified as the giant cell variant of MFH. Considering that at least some other reported cases of giant cell MFH appear to be a variant of extraskeletal osteosarcoma, we would suggest that lesions with this distinctive pattern should be more carefully classified according to their apparent line of differentiation.

Aged↗
PubMed1993

Dermatomyofibroma: additional observations on a distinctive cutaneous myofibroblastic tumour with emphasis on differential diagnosis.

Following the very recent description of a benign plaque-like myofibroblastic tumour of the skin, known as dermatomyofibroma, we present four further cases, emphasizing its clinical features and its histological differential diagnosis. Three patients were adult females and one was a boy. Two of the lesions arose on the anterior abdominal wall, one on the shoulder, and one on the neck. Clinically, there was often close resemblance to a keloid. Follow-up revealed no evidence of recurrence after simple excision. Histologically, these were non-encapsulated but well-circumscribed, plaque-like lesions located in the reticular dermis, and composed of fascicles of monomorphic myofibroblasts, orientated parallel to the skin surface. Immunohistochemically, most of the tumour cells expressed alpha-smooth-muscle actin. The principal differential diagnosis is plaque-stage dermatofibrosarcoma protuberans. Other differential diagnoses include diffuse neurofibroma, dermatofibroma and other myofibroblastic skin tumours.

Actins↗
PubMed1993

Lipoblastoma and lipoblastomatosis: a clinicopathological study of 14 cases.

The clinicopathological features of 14 cases of lipoblastoma and lipoblastomatosis are presented. The age of the patients at presentation ranged from 5 days to 6 years (mean 2.7 years); nine patients were male. Histologically, six cases were circumscribed (lipoblastoma) while eight were diffuse and ill-defined (lipoblastomatosis). In both groups and in individual cases there was distinct lobulation, as well as a spectrum of adipocytic maturation. Cytologically, the 10 most mature lesions were composed of uniform adipocytes intermixed with only scattered lipoblasts and primitive mesenchymal cells. A notable feature in the other four cases was a prominent myxoid stroma producing a very close resemblance to myxoid liposarcoma. Mitotic figures were rare and always normal in appearance. Atypical nuclei were not evident. Follow-up in eight patients revealed local recurrence in two. Liposarcoma in patients under 10 years is exceedingly rare, and, in myxoid form, may be almost impossible to distinguish histologically from lipoblastoma. Helpful clues are the lack of lobulation, variable growth pattern and increased nuclear atypia in liposarcoma.

Child↗