Giant cell angiofibroma. A distinctive orbital tumor in adults.

A series of seven cases of a previously unrecognized potentially recurrent tumor occurring in the orbit of adult patients is reported. This lesion shows histologic appearances intermediate between, but distinct from, solitary fibrous tumor and giant cell fibroblastoma of soft tissue. Morphologically it is characterised by a richly vascularized, patternless spindle-cell proliferation containing pseudovascular spaces.

Malignant fibrous histiocytoma: morphologic pattern or pathologic entity?

Since the concept of malignant fibrous histiocytoma (MFH) was introduced and subsequently popularized in the 1960's and 1970's, it has become widely regarded as the commonest soft-tissue sarcoma of adulthood. Although the initial notion that MFH was a true histiocytic tumor showing faculative fibroblastic differentiation has been disproved, and despite the lack of definable, reproducible diagnostic criteria and considerable immunophenotypic, ultrastructural and karyotypic heterogeneity, MFH is still accepted widely as a discrete clinicopathologic entity. On the other hand several recent studies have expressed considerable doubts about MFH, or at least pleomorphic MFH, as an "entity" and have suggested that it represents a common morphologic manifestation of a host of poorly differentiated sarcomas and, more rarely, other neoplasms.

[The histological features of local recurrences of soft tissue sarcomas].

Local recurrence is a well-recognised problem in soft tissue sarcomas, especially at difficult anatomical locations or after inadequate surgery. It is logical to assume that such recurrence will have an adverse effect on prognosis. In most cases the histological appearance of the recurrence is very similar to that of the primary neoplasm, in view of the fact that recurrence is most common in high-grade (poorly differentiated) sarcomas.

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).

[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.

Rhabdomyosarcoma in adults.

Rhabdomyosarcomas occur in adults in one of two forms; as sporadic cases of the juvenile histological types and more commonly, if controversially, as the major adult form, pleomorphic rhabdomyosarcoma. This review documents the historical background to the fluctuating diagnostic popularity of pleomorphic rhabdomyosarcoma, together with a presentation of its defining clinicopathologic characteristics, and presents the clinicopathologic features of the juvenile types as they occur in adults. The concept of pleomorphic rhabdomyosarcoma as a distinct clinicopathologic entity, presenting as an aggressive, predominantly spindle-cell tumor arising in the skeletal musculature of middle-aged adults and defined by the presence of large, pleomorphic tumor cells, which show, at least focally, immunophenotypic or ultrastructural sarcomeric muscle differentiation, is discussed and supported.

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.

New entities in cutaneous soft tissue tumours.

Connective tissue tumours represent a significant group among biopsied skin lesions and manifest a wide range of morphological patterns. While the majority are easily diagnosed, notably most fibrous histiocytomas and neural lesions, a proportion pose considerable diagnostic difficulty. With the increasing recognition and characterisation of previously undescribed entities within the family of soft tissue tumours in recent years, the number of unclassifiable lesions should diminish.

Pleomorphic malignant fibrous histiocytoma: fact or fiction? A critical reappraisal based on 159 tumors diagnosed as pleomorphic sarcoma.

Pleomorphic malignant fibrous histiocytoma (MFH) is regarded as the most common soft tissue sarcoma of adulthood, but no definable criteria exist for its diagnosis. Possibly its only distinctive feature is its apparent lack of specific differentiation. To determine the validity of pleomorphic MFH, 159 tumors diagnosed as pleomorphic sarcomas have been reassessed morphologically, immunohistochemically, and ultrastructurally, where possible.

Malignant peripheral nerve sheath tumour with annulate lamellae mimicking pleomorphic malignant fibrous histiocytoma.

The nature and nosologic status of malignant fibrous histiocytoma (MFH), or at least its most common pleomorphic variant, are a matter of controversy and it is possible that this entity represents the shared morphologic phenotype of a range of other dedifferentiated neoplasms. An unusual case of malignant peripheral nerve sheath tumour which very closely mimicked pleomorphic MFH is presented. Its true nature was only disclosed by ultrastructural examination.

Sarcomatoid tumours of lymph nodes showing follicular dendritic cell differentiation.

Putative sarcomas of follicular dendritic cells are extremely uncommon and only small case numbers have been clearly documented. A major difficulty in their delineation has been the persistent controversy over the phenotype and ontogeny of normal follicular dendritic cells. Two new cases arising in adult females are presented herein, both of which had initially been mistaken for metastases from a true soft tissue sarcoma.

Cell kinetics of human gastric mucosa and gastric cancer in organ culture.

The cell kinetics of human gastric epithelium in organ culture have been measured using flash labelling with tritiated thymidine and the metaphase arrest technique to estimate cell birth rates. Normal gastric antral and body mucosa have been compared with mucosa showing gastritis and gastric carcinoma. Labelling indices with tritiated thymidine in normal gastric mucosa declined over a 48-h period suggesting that essential growth factors were lacking.