Thyroglobulin in orbital tissues from patients with thyroid-associated ophthalmopathy: predominant localization in fibroadipose tissue

One of the hypotheses that explains the pathogenesis of thyroid-associated ophthalmopathy (TAO) is that thyroglobulin (Tg) is transported through a retrograde lymphatic route to orbital tissues (OT), where it elicits autoimmune damage. In a previous study we demonstrated the presence of intact Tg of thyroid origin in OT from three patients with TAO. The present study was undertaken to investigate this issue further, by increasing the number of patients, by analyzing the distribution of Tg in OT, and by investigating possible relations between the presence of Tg in OT and the clinical features of patients. OT was obtained from seven patients with TAO who underwent decompressive orbitotomy via a transpalpebral approach. Patients were designated P10 to P16. Inflamed palpebral skin, retrobulbar fibroadipose tissue and extraocular muscle surgical samples were collected separately. Tissue extracts were prepared by homogenization and analyzed for the presence of Tg using two different techniques. We first performed immunoprecipitation experiments, in which a rabbit polyclonal anti-Tg antibody was used to capture Tg on protein A and a mouse monoclonal anti-Tg antibody was used to re-veal captured Tg by Western blotting. Intact 330-kd Tg was detected in retrobulbar fibroadipose tissue extracts from three patients (P10, P11, and P16), whereas no Tg was detected in retrobulbar fibroadipose tissue extracts from the remaining four patients. Tg was not detected in the extraocular muscle extracts from all patients studied. In addition, intact 330-kd Tg was found in the inflamed palpebral skin extract from one patient (P10). No Tg was detected in OT extracts from two patients without thyroid or eye disease and in abdominal adipose tissue extracts from two obese patients without thyroid or eye disease. We then searched for Tg by enzyme-linked immunosorbent assay (ELISA), using the same antibodies used for immunoprecipitation. Tg was detected in retrobulbar fibroadipose tissue extracts from four patients (P10, P11, P12, and P16) and in the inflamed palpebral skin extract from patient P10, in amounts ranging from approximately 125 to approximately 400 pg/microg of tissue protein. Again, Tg was not detected in extraocular muscle extracts. A positive gradient between Tg in OT and Tg in the serum was observed in patient P12. Using an ELISA approach, we found that Tg in OT from three TAO patients (P10, P11, and P12) contained thyroxine (T4) residues (mean T(4)

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2.42 molecules per molecule of Tg), indicating that Tg had originated in the thyroid. Combining the results obtained in our previous and present study, we found a possible relation between the presence of Tg in OT and the previous treatment with radioiodine. Thus, of the seven patients (3 in the previous and 4 in the present study) in whose OT Tg was found, six had been treated with radioiodine, whereas of the three patients with no Tg in their OT none had been treated with radioiodine. In conclusion, Tg was found in OT extracts from patients with TAO by immunoprecipitation in three of seven cases and by ELISA in four of seven cases. Tg was found in retrobulbar fibroadipose tissue, but not in extraocular muscles. There was a relation between the presence of Tg in OT and the previous treatment with radioiodine. Our results support the hypothesis that Tg may play a role as a coantigen in the pathogenesis of TAO. Further studies are needed to investigate this possibility.

Effects of transforming growth factor-beta1 and tumour necrosis factor-alpha on cultured fibroblasts from skin fibroma as modulated by toremifene

To determine how toremifene, an anti-oestrogen triphenylethylene derivate, reduces tumour mass, we investigated its modulation of TGF-beta1 and TNF-alpha in fibroma fibroblasts. Normal and fibroma fibroblasts, isolated from patients affected by Gardner's syndrome without or with fibroma manifestation, were cultured in vitro. Secretion of GAG, collagen and TGF-beta1 was increased in fibroma fibroblasts compared to healthy cells. The increase in TGF-beta1 secretion into the medium was associated with a parallel increase in TGF-beta1 gene expression and receptor number. Receptor cross-linking studies using radiolabelled TGF-beta1 revealed more receptors, particularly types I and II, in fibroma fibroblasts than in normal cells. Normal and fibroma fibroblasts did not synthesise TNF-alpha, but they had TNF-alpha membrane receptors, as shown by TNF-alpha assay. TNF-alpha secreted by human monocytes, which may be present in the peritumoral area, increased cell proliferation and GAG accumulation and was, in turn, enhanced by TGF-beta1 treatment. Both growth factors increased angiogenesis, as shown by the CAM assay. Toremifene reduced TGF-beta1 secretion by fibroma fibroblasts and TNF-alpha secretion by monocytes, thus downregulating cell proliferation, ECM macromolecule accumulation and angiogenic progression. We hypothesise that increased TGF-beta1 gene expression and TGF-beta1 secretion in fibroma fibroblasts as well as the subsequent rise in TNF-alpha production by monocytes may facilitate fibroma growth and that toremifene inhibits autocrine and paracrine growth factor production.

Superficial collagenous fibroma: immunohistochemical, ultrastructural, and flow cytometric study of three cases, including one pemphigus vulgaris patient with a dermal mass

Collagenous fibroma (desmoplastic fibroblastoma) is an extremely rare benign soft tissue tumor of fibroblastic origin. The majority of reported cases have been located in the deep subcutis, fascia, aponeurosis, or skeletal muscle of the extremities, limb girdles, or head and neck regions. There has been no mention of underlying diseases in patients who developed this tumor. We here report an additional three cases of superficial collagenous fibroma, one of which was a dermal lesion occurring in the abdomen of a 26-year-old male patient with a 5-year history of pemphigus vulgaris prior to development of the tumor. To the best of our knowledge, an association between collagenous fibroma and pemphigus vulgaris has not previously been reported. The remaining two tumors were located in the superficial subcutaneous tissue of the infrascapular area and right foot, respectively. There was no tumor recurrence or metastasis during follow up of 18, 25, and 47 months, respectively. All three tumors were well-circumscribed and unencapsulated without infiltrating borders. Histologically, the common denominator of all three cases was paucicellular proliferation of spindle or stellate fibroblasts enmeshed within an extensively collagenous background. Immunohistochemically, there was diffuse strong staining for vimentin and intense focal reaction for smooth muscle actin in two tumors tested. Electron microscopy revealed features consistent with a fibroblastic or myofibroblastic lineage. Flow cytometry in two cases demonstrated a diploid DNA content with low S-phase fractions, which correlated with minimal MIB-1 nuclear labeling (less than 1%) and benign behavior of this entity.

Vimentin, smooth muscle actin, desmin, S-100 protein, p53, and estrogen receptor expression in elastofibroma and nodular fasciitis

Elastofibroma and nodular fasciitis are two rare, benign soft tissue tumors. Elastofibroma is suggested to develop as a result of abnormal degeneration of elastic fibers after local trauma. Similarly, fibroblastic proliferation, which is triggered by local trauma or nonspecific inflammatory event, is suggested to play an important role in the origin of nodular fasciitis. In this immunohistochemical study, vimentin, smooth muscle actin (SMA), desmin, S-100 protein, p53, and estrogen receptors were applied to paraffin sections of 10 elastofibroma and four nodular fasciitis specimens to learn more about their histogenesis and biological behavior. All cases with nodular fibrosis were strongly SMA and vimentin positive, while only three weakly stained with estrogen receptor antibody. There was no immunreactivity for S-100, desmin, and p53 in nodular fasciitis. However, all elastofibroma cases were stained positively with vimentin. No staining was observed with SMA, S-100, desmin, and p53 in elastofibroma. The staining pattern of nodular fasciitis supported a myofibroblastic origin, whereas the SMA negativity in elastofibroma was correlated with fibroblastic origin.

Collagenous fibroma (desmoplastic fibroblastoma) of the finger in a child

Collagenous fibroma (desmoplastic fibroblastoma) is a distinctive benign fibrous soft tissue tumor that typically occurs in the subcutaneous tissue or skeletal muscle in adults. We describe a case of collagenous fibroma in a 7-year-old boy who presented with a 1-cm solitary, firm nodule on the volar aspect of the metacarpophalangeal joint of the left little finger. Microscopically, the tumor was composed of spindle- and stellate-shaped cells embedded in a hypovascular, densely collagenous stroma. No mitotic figures, calcifications or necrosis were identified. Immunohistochemically, tumor cells were diffusely positive for vimentin, but negative for smooth muscle actin, muscle-specific actin, desmin, cytokeratin, S-100 protein or CD34. To our knowledge, this is the second reported case of collagenous fibroma in children. Our case report indicates that the clinicopathological features of collagenous fibroma in childhood are similar to those in adults.

A case of solitary fibrous tumor of the meninges

We report a rare case of solitary fibrous tumor (SFT) of the meninges of the posterior fossa presenting as an intracerebellar hemorrhage. A 29-year-old woman was admitted with sudden-onset severe headache, nausea, and vomiting. A computed tomographic (CT) scan of the brain revealed an intracerebellar hemorrhage 3.5cm in diameter. Gadolinium-enhanced magnetic resonance imaging (MRI) showed a heterogeneous enhancement mass. A posterior craniotomy found a firm, highly vascular tumor attached to the meninges. Histologically, the tumor showed mostly sclerotic tissues with spindle cells. In few areas, the tumor had a more compact arrangement of spindle-shaped cells with vascular spaces and highly cellular components. Immunohistochemical study revealed strong CD-34 immunopositivity in many tumor cells. The tumor was diagnosed as SFT of the meninges. We report the clinical and histological features of this newly described tumor with a heterogeneous component.

Fibromatosis of the breast and mutations involving the APC/beta-catenin pathway

Fibromatoses of the breast are nonmetastasizing tumors, but can be infiltrative and locally recurrent. Breast fibromatoses are rare, and their specific genetic alterations have not been elucidated. However, their occasional occurrence in patients with familial adenomatous polyposis (FAP) and their morphologic identification with other deep fibromatoses (desmoid tumors) suggest that alterations of the APC/beta-catenin pathway might be involved in the pathogenesis of sporadic and FAP-associated breast fibromatoses. We analyzed somatic beta-catenin and APC gene mutations in 33 breast fibromatoses (32 sporadic and 1 FAP-associated) using immunohistochemistry for beta-catenin, 5q allelic loss assays, and direct DNA sequencing for exon 3 of the beta-catenin gene and the mutation cluster region of the APC gene. Nuclear accumulation of beta-catenin was present in the stromal tumor cells in most (82%) cases but not in normal stroma or mammary epithelial cells. Somatic alterations of the APC/beta-catenin pathway were detected in 79% of breast fibromatoses, including activating beta-catenin gene mutations in 15 cases and somatic APC alterations (mutation or 5q allelic loss or both) in 11. These findings indicate that alterations of the APC/beta-catenin pathway with resultant nuclear translocation of beta-catenin are important in the pathogenesis of both sporadic and FAP-associated breast fibromatosis. The spectrum of beta-catenin and APC alterations is similar to that described for desmoid tumors of the abdomen, paraspinal region, and extremities.

Papillary carcinoma of the thyroid gland forming a myofibroblastic nodular tumor: report of two cases and review of the literature

We encountered two unique cases of papillary carcinoma of the thyroid gland forming fibroma-like nodular tumors. The two cases showed well-defined nodules composed largely of fibromatosis-like stroma with small foci of papillary carcinoma. This type of tumor is relatively rare and has been reported with the name of 'papillary carcinoma of the thyroid with fibromatosis-like stroma or nodular fasciitis-like stroma'. The stromal cells have had myofibroblastic features in all reported cases, including the present cases. The pathogenesis of this tumor is still unknown. We must be careful to differentiate this type of thyroid tumor from fibrosarcomatous anaplastic carcinoma, particularly in the intraoperative consultation. We speculate that this unique tumor is an autonomous proliferation of stromal cells, based on the immunohistochemical analyses of early stromal changes in usual-type papillary carcinoma of the thyroid. The present names of this disease may not represent the proper features of this tumor because all the reported cases formed fibroma-like nodules. We propose the name 'papillary carcinoma forming myofibroblastic nodular tumors'.

Orbital hemangiopericytoma and solitary fibrous tumor: a morphologic continuum

Solitary fibrous tumors (SFT) and hemangiopericytomas (HPC) are soft tissue tumors with known histologic and immunohistochemical overlap. A series of these tumors located in the orbit were analyzed in order to determine whether they could be re-classified based on currently recognized histologic criteria. Ten orbital spindle cell lesions, all of which were positive for CD34 antigen, were examined. Diagnostic criteria for SFT included a cytologically bland spindle cell lesion with variable cellularity and focal dense collagenization with diffuse, strong CD34 reactivity, while the criteria for HPC required a more monotonous cellular proliferation without significant variability in cellularity, a "staghorn" vascular pattern, minimal collagenization, and focal or absent CD34 staining. Tumors with typical histologic and immunohistochemical features of HPC or SFT were diagnosed as HPC and SFT, respectively. Those tumors with histologic or antigenic profiles not classic for HPC or SFT were defined as 'indeterminate.' Three lesions were classified as SFT and 1 tumor was diagnosed as HPC through use of the above-cited histologic criteria. All lesions showed positive staining of tumor cells with CD34 antigen in varying amounts and were negative for cytokeratin AE1-3, epithelial membrane antigen, CD68, and Factor XIIIa. One solitary fibrous tumor focally stained for S-100 protein and 1 hemangiopericytoma was focally positive for HHF-35. Of the 10 analyzed tumors, 6 were classified as 'indeterminate.' Furthermore, 1 lesion whose primary histology was that of an SFT recurred 9 years later with an appearance consistent with an 'indeterminate' lesion. Our results call into question the present histologic separation of HPC and SFT in the orbit. As in other sites, including deep soft tissue, these data suggest that SFT and HPC are 2 lesions whose morphologic features are best interpreted to exist along a continuum, rather than 2 lesions with distinctly defined histopathology.

Solitary fibrous tumor of the oral soft tissues: a clinicopathologic and immunohistochemical study of 16 cases

We describe the clinicopathologic and immunohistochemical features of 16 solitary fibrous tumors (SFTs) originating within the oral soft tissues. There were 10 women and six men with a mean age at diagnosis of 56 years. In all cases the tumors were slow-growing, asymptomatic, submucosal growths of variable size and duration. The buccal mucosa was involved in 12 cases, and the tongue and lower lip were affected in two cases, respectively. Thirteen tumors developed on the left side of the mouth. Follow-up information was available in 10 cases and averaged 44.7 months, with no evidence of recurrence or metastasis. All 16 tumors were well circumscribed and demonstrated histologic features that were invariably benign. In all cases they were composed of an admixture of alternating hypercellular and hypocellular, collagenous zones; haphazardly arranged, cytologically bland spindle and ovoid cells that in areas were intimately intermixed with collagen; a prominent vasculature; and perivascular hyalinization. Immunohistochemically, the tumors were consistently positive for CD34, bcl-2, factor XIIIa, and vimentin, whereas 75% of the tumors were reactive for CD99. To further define the clinicopathologic profile of intraoral SFT, we include a review of the previously reported cases. We also include a comparison and brief review of the clinicopathologic and immunohistochemical features of other spindle cell tumors of the oral cavity, from which SFTs must be differentiated.

Superficial fibromatoses are genetically distinct from deep fibromatoses

Whereas deep fibromatoses (abdominal, extra-abdominal, mesenteric) display locally aggressive behavior, superficial fibromatoses typically remain small and less likely to recur despite essentially identical morphology. Somatic beta-catenin or APC gene mutations have been reported in < or =74% of sporadic deep fibromatoses and in virtually 100% of Gardner syndrome-associated fibromatoses, whereas genetic events in superficial fibromatoses remain less well characterized. We performed immunohistochemical staining for beta-catenin on 29 superficial fibromatoses (22 palmar, 5 plantar, 1 penile, and 1 infantile digital fibromatosis) and 5 deep fibromatoses. Mutations of beta-catenin and APC genes were analyzed in cases of superficial fibromatoses by direct DNA sequencing of the beta-catenin gene on Exon 3 encompassing the GSK-3 36 phosphorylation region and of the APC gene on the mutation cluster region. Nuclear accumulation of beta-catenin was present in 86% (25/29) of superficial fibromatosis cases ranging from 5 to 100% of nuclei (mean, 13%; median, 10%), though in a minority of nuclei in most examples. Deep fibromatoses had 60 to 100% nuclear staining in all five cases. No somatic mutations of beta-catenin or APC genes were identified in any of the superficial fibromatoses. In contrast to deep fibromatoses, superficial fibromatoses lack beta-catenin and APC gene mutations; the significance of focal nuclear beta-catenin accumulation is unclear. This difference may account inpart for their divergent clinical manifestations despite their morphologic resemblance to deep fibromatoses.

Detection of c-fos expression in benign and malignant musculoskeletal lesions

The proto-oncogene c-fos has been implicated in the development of both benign and malignant lesions of bone. Although c-fos expression in such lesions has been well studied in transgenic mouse models, less is known about its role in human musculoskeletal pathology. To clarify this relationship, we used in situ hybridization to localize c-fos m-RNA transcripts in 26 fibrous lesions (eight cases of extra-abdominal fibromatosis and six cases each of fibrous dysplasia, fibrosarcoma, and malignant fibrous histiocytoma of bone) as well as six chondrosarcomas and eight conventional high grade osteosarcomas. We found detectable levels of c-fos expression in tissues from each type of lesion tested. Moreover, all fibrous lesions consistently demonstrated high levels of expression in a majority of cells in each lesion. Chondrosarcomas and osteosarcomas exhibited more heterogeneity in c-fos expression than fibrous tissues. Three of six chondrosarcomas showed moderate expression of c-fos while only one of six was considered high. Similarly, only three of eight osteosarcomas had high expression of c-fos. These findings indicate that the expression of c-fos may be important in the development of a broad range of fibrous lesions as well as in bone and cartilaginous tumors. Additionally, this is the first report, to our knowledge, of detectable c-fos m-RNA in human chondrosarcoma.

Hypoglycemia induced by secretion of high molecular weight insulin-like growth factor-II from a malignant solitary fibrous tumor of the pleura

A 49-year-old woman with a malignant solitary fibrous tumor of the pleura presented with hypoglycemia. Most of the serum insulin-like growth factor II (IGF-II) existed as high molecular weight IGF-II. Furthermore, there were larger amounts of high molecular weight IGF-II found in the tumor cystic fluid than in the serum. After surgical resection of the tumor, high molecular weight IGF-II was not detected in the serum and the hypoglycemia resolved. Immunohistochemically, IGF-II was localized in the so-called Golgi area of the tumor cell. These findings suggest that hypoglycemia in this patient was caused by the high molecular weight IGF-II produced by the tumor.

Giant-cell fibroblastoma: a case report emphasising the presence of hyperplastic subplasmalemmal linear densities in continuity with granular matrices in the extracellular space

The histological, immunohistochemical and ultrastructural features of a case of giant-cell fibroblastoma from the soft tissues of the chest wall in a 48-year-old female are described with special reference to the cell surface and matrix. Subplasmalemmal linear densities (SLDs) characterised cell surfaces, and exhibited excessive development of the dense external component: foci of identical dense material were present in the matrix. The nature of these dense foci, both the external component of the SLD and those free in the extracellular space, was investigated by light microscope immunostaining for fibronectin, laminin and collagen IV. All three proteins stained vessels. There was weaker but positive staining for tumour cell surfaces and matrix, consistent with the widely dispersed nature of the dense foci. Given their fine structural appearance, these dense foci can be referred to as granular matrices. Given also that the matrix protein immunostaining pattern is consistent with the distribution of these granular matrices as observed by electron microscopy, they may be provisionally interpreted as a kind of basement-membrane-related granular matrix. The presence of these proteins emphasises the point that, while giant-cell fibroblastoma fibroblasts lack a lamina, they nevertheless bear basement-membrane-related proteins organised, however, in a non-laminate fashion. The observations reinforce the need to qualify immunostaining results by ultrastructural investigation in order to understand the organisation of immuno-detected proteins and are discussed in terms of their diagnostic and possible biological significance.

Low-grade fibromyxoid sarcoma and hyalinizing spindle cell tumor with giant rosettes: a clinicopathologic study of 73 cases supporting their identity and assessing the impact of high-grade areas

Low-grade fibromyxoid sarcoma (LGFMS) is a rare sarcoma characterized by bland histologic features and a paradoxically aggressive clinical course. The hyalinizing spindle cell tumor with giant rosettes (HSCT) is a closely related tumor characterized by the presence of giant collagen rosettes. Only a single example of a metastasizing HSCT has been reported. A small subset of both LGFMS and HSCT display areas of increased cellularity and atypia which qualify as intermediate- to high-grade sarcoma; the significance of these features has not been definitively assessed. We present the clinicopathologic features of 77 cases of LGFMS and HSCT to determine the degree of overlap of these two lesions, their biologic behavior, and the significance of the occasional presence of intermediate- to high-grade sarcoma within both. The patients (33 female, 40 male) ranged from 3 to 78 years of age (median, 34 yrs). Fourteen cases occurred in patients less than 18 years of age. The tumors measured from 1 to 23 cm (median, 4.5 cm) and occurred predominantly in the trunk and lower extremities in both the deep (66 cases) and superficial (7 cases) soft tissues. In 15 cases, the tumor was present > 1 year before diagnosis. All tumors showed predominantly the typical hypocellularity and bland cytologic features of typical LGFMS; however, areas of hypercellularity and nuclear enlargement and hyperchromatism were identified in 12 of 73 (16%) and 7 of 73 (10%), respectively. Necrosis and mitotic activity >5/50 high-powered fields (HPF) were present in 6 of 73 (8%) and 5 of 73 (7%), respectively. Epithelioid areas were present in 33 of 73 (45%) and rosettes in 22 of 73 (30%). Follow up (54 cases; range, 2-192 mos; median, 24 mos; mean, 38 mos) showed 5 recurrences, 3 metastases, and 1 death. The diagnosis of LGFMS or HSCT was made prospectively in 51 patients; none had metastatic disease. Two of the metastatic tumors were LGFMS and one was a HSCT. LGFMS may occur more often in the pediatric population and show a much wider histologic spectrum than previously thought. A significant number of LGFMS possess inconspicuous collagen rosettes characteristic of HSCT, indicating that these two tumors are ends of a common spectrum rather than distinct entities. HSCT, like LGFMS, are low-grade sarcomas with metastatic potential. The presence of focal areas of intermediate- to high-grade sarcoma does not portend a worse outcome in the short term. The better prognosis reflected in this study compared with previous ones might reflect the fact that all were initially diagnosed as sarcomas and treated with aggressive surgery. The fact that the only three patients to develop metastatic disease were patients whose LGFMS or HSCT was identified retrospectively supports this concept.

An improved system for quantifying AgNOR and PCNA in canine tumors

BACKGROUND

Quantifying silver stained nucleolar organizer regions (AgNORs) and proliferation cell nuclear antigens (PCNA) are useful techniques to measure proliferative activity of tumor cells; however, the nonspecific deposition of stains and overlappings of AgNOR and PCNA counts between grades of tumors hamper their applications.

MATERIALS AND METHODS

Fifty-two surgical specimens from dogs, including mast cell tumors, perianal gland tumors and hyperplasias, fibromas, fibrosarcomas, and normal tissues were studied. The 3 microns dewaxed sections of formalin-fixed tissues were stained to detect AgNORs by a modified inverted incubation technique in a newly developed silver staining device. Data were collected and analyzed using a high-resolution digital microscope camera and image analysis software. Sequential sections were also stained for PCNA using an immunohistochemical method.

RESULTS

The improved system for quantifying AgNOR provided more accurate and non-overlapping mean AgNOR counts, which enable us to distinguish benign states from malignant changes. The mean AgNOR cut-off points that discriminated grade II or III mast cell tumors from grade I, perianal gland carcinomas from adenomas (or hyperplasia), fibrosarcomas from non-fibrosarcoma tissues, were 6.0, 14.1, 9.4, and 8.8 respectively. The mean AgNOR areas, relative AgNOR areas, and PCNA positive rates of some malignant and non-malignant tissues (benign tumor and normal tissues) were significantly different (P < 0.05).

CONCLUSIONS

This improved system is a sensitive and rather precise method for quantifying the AgNOR and PCNA. It provides a valuable objective measurement for differentiating benign and malignant tumors.

Juvenile hyaline fibromatosis: clinical heterogeneity in three patients

BACKGROUND

Systemic hyalinoses are genetic generalized fibromatoses characterized by an accumulation of hyalin in the dermis. Two distinctive syndromes are recognized in the literature: infantile systemic hyalinosis (ISH) and juvenile hyaline fibromatosis (JHF). ISH and JHF are sometimes difficult to separate since they show significant overlap.

OBSERVATIONS

We report on 3 children from two unrelated families suffering from JHF. The first child is severely handicapped by joint contracture, massive hyperplasia of the gingivae, diffuse skin papules and subcutaneous nodules occupying the scalp, face, perianal area, palms, soles and chest. At the same age, the second child only shows pearly skin papules on the face, groin and perianal area and gingival hyperplasia without joint stiffness or any other subjective complaint. The third patient, a brother of the second child, developed mild skin abnormalities by the end of the first year. The occurrence in siblings and consanguinity in the second family suggests autosomal recessive inheritance. Histological skin examination in the 3 cases showed hyaline deposition in the dermis and abnormal ultrastructure of fibroblasts. Biochemical findings showed mucopolysaccharide abnormalities in both families.

CONCLUSION

Our patients do not only illustrate the different expressions of JHF but also show some overlap with ISH, suggesting a common cause for both disorders. Genetic studies will finally answer this question.

Systemic hyalinosis of delayed onset

We report a 46-year-old Japanese male with systemic hyalinosis. The condition had not been present during youth but was clearly evident in the patient's forties. The present case is remarkable because of a delayed onset.

Pleomorphic sclerotic fibroma

We report the clinical and histologic features of 2 cutaneous tumors demonstrating many of the usual features of sclerotic fibroma, an entity that is well described in the literature. Our cases differed from the usual form of sclerotic fibroma in that they demonstrated marked focal cellular pleomorphism without increased mitotic activity. We suggest the term pleomorphic sclerotic fibroma for these lesions.

Low-grade fibromyxoid sarcoma: a report of eight cases with histologic, immunohistochemical, and ultrastructural study

We present eight cases of low-grade fibromyxoid sarcoma (LGFS) of soft tissues. The patients, six men and two women, ranged in age from 28 to 44 years (median, 39 years). All tumors were subcutaneous. They were located in the lower extremity (three cases), inguinal/perineal region (two cases), trunk (one case), upper extremity (one case), and neck (one case). Grossly, the lesions were similar to those described in previous studies; fibrous and well circumscribed, with pseudocapsules, and without any necrosis or nodularity. In a single case of hemosiderin-rich tumor, rusty brown strips were seen on the cut surface. Histologically, the tumors were composed of alternating fibrous and myxoid areas with various cellularity and with swirling and whorled growth patterns. The cells were stellate or spindle shaped and displayed none to mild nuclear pleomorphism and hyperchromasia. Some hypercellular areas showed a fascicular or herring bone pattern similar to common fibrosarcomas. In addition to the known typical picture of LGFS, we also have seen some unusual features. The cells of myxoid areas were often arranged in rows, thus resembling ossifying fibromyxoid tumor or myxoid chondrosarcoma of soft tissues. In a single case, the tumor cells contained a large amount of hemosiderin and the cellular nests contained synovial metaplasia-like clefts. The intranuclear invaginations of cytoplasm represented another interesting finding that was present in all tumors in our series. They seem to be constant or at least frequent features of LGFS, which may assist in the differential diagnosis. The immunohistochemical and ultrastructural findings were consistent with the fibroblastic nature of LGFS. Four cases also showed features of possible histiocytic modulation of the neoplastic fibroblasts.

Solitary fibrous tumour of the orbit. Report of a new case

PURPOSE

Solitary fibrous tumour (SFT) of the orbit is a very rare lesion that may be misdiagnosed as fibrous histiocytoma, haemangiopericytoma, or other orbital tumour. We studied a case of SFT of the orbit in a 35-year-old woman.

METHODS

The patient, with a 1-year history, reported a 'pressure' sensation behind her right eye, but no pain, vision changes, or other associated symptoms. Ocular examination was normal. Magnetic resonance imaging (MRI) showed a well-circumscribed medial mass in the right orbit. The tumour was excised.

RESULTS

The tumour was a cellular spindle-cell neoplasm with a storiform pattern. The tumour cells were spindle-shaped with bland nuclei and rare mitoses. Immunostaining was positive for vimentin and CD34, but negative for cytokeratin (AE1-AE3), EMA, desmin, smooth muscle actin, S-100, CD31, CD45 and bcl-2.

CONCLUSION

SFT can infrequently involve the orbit. The tumour must be removed entirely to avoid recurrences. Careful and continued follow-up is important because orbital recurrence may occur several years after the excision of the primary tumour.

Fibromatosis of the mesoappendix

Mesenchymal tumors of the appendix are very rare. Mesenteric fibromatosis is the most common diagnosis in the case of isolated proliferative fibroblastic lesion found in this region. However, the differential diagnosis between fibromatosis and well-differentiated fibrosarcoma (Grade I) can be difficult in some borderline cases. A rare case of proliferative fibroblastic lesion involving the appendix and mesoappendix is presented, and its origin, diagnosis and differential diagnosis are discussed.