Intraventricular solitary fibrous tumor: an unusual tumor with radiological, ultrastructural, and immunohistochemical evaluation: case report

OBJECTIVE AND IMPORTANCE

Intracranial solitary fibrous tumors have been described previously, but intraventricular solitary fibrous tumors are extremely rare. We present what is, to our knowledge, the first reported case of solitary fibrous tumor in the third ventricle.

CLINICAL PRESENTATION

A 63-year-old man presented with weakness of his lower extremities and headaches. Computed tomography and magnetic resonance imaging of the brain revealed an enhancing mass in the posterior part of the third ventricle.

INTERVENTION

The tumor originated from the wall of the left internal cerebral vein and extended to the posterior part of the third ventricle. Nearly total excision was performed via an infratentorial-supracerebellar approach.

CONCLUSION

The differential diagnosis of intracranial solitary fibrous tumors includes fibroblastic meningioma, meningeal hemangiopericytoma, neurofibroma, and schwannoma. The differential diagnosis in the present case was greatly helped by the immunohistochemical and ultrastructural findings, along with a disease-free 3.5-year follow-up. These findings are presented with reference to previous reports.

Transforming growth factor-α and oral fibroma: immunohistochemical and in situ hybridization study

PURPOSE

Transforming growth factor-alpha (TGF-alpha) is usually expressed in cell lines derived from sarcomas. It is known as a mitogen for fibroblasts. The aim of this study was to determine whether there were any differences in the expression pattern of TGF-alpha between normal oral mucosa and oral fibroma.

PATIENTS AND METHODS

Fourteen pathologic specimens (6 males and 8 females; 37.2 +/- 23.2 years) and 10 normal oral mucosal specimens (5 females and 5 males; 43.8 +/- 17.7 years) were used for this study. Identification of TGF-alpha was sought by using immunohistochemistry and in situ hybridization.

RESULTS

The samples from normal oral mucosa did not express TGF-alpha. One sample from oral fibroma did not express TGF-alpha (7.1%). Five samples from oral fibroma expressed TGF-alpha sparsely (35.7%). Eight samples showed diffuse expression of TGF-alpha (57.1%). The immunopositive reaction to TGF-alpha in oral fibroma was localized in the basal layer and the fibroblasts that resided beneath the epithelium. This pattern was also shown in the in situ hybridization study as well.

CONCLUSION

TGF-alpha is expressed in oral fibromas. It suggested that TGF-alpha might play a role in fibroblast proliferation in oral fibromas.

Androgen-dependent atypical fibromas spontaneously arising in the skin of Djungarian hamsters (Phodopus sungorus)

Spontaneous atypical fibromas that arose in the thoracoabdominal skin of one aged female and 31 aged male Djungarian hamsters (Phodopus sungorus) were examined histologically, immunohistochemically, and ultrastructurally. The normal skin from both sexes obtained at various intervals until the age of 12 months was examined, as were the tumors. These tumors were composed of ganglion cell-like (GL) cells that had one or two ovoid nuclei, basophilic foamy cytoplasm, and various amount of collagen fibers between the cells. The tumor cells had positive reaction to vimentin and androgen receptor (AR); the stromal collagen fibers reacted positively with the antibody against collagen type I or III. Ultrastructurally, the tumor cells had abundant rough endoplasmic reticulum in the cytoplasm. On the other hand, small nests of the cells mimicking tumor GL cells were present in the dermal layer to the panniculus of the normal thoracoabdominal skin of adult males, but were seldom found in adult females. The morphologic and immunohistochemical features of these tumor GL cells were basically similar to those of normal skin GL cells, although the former had a certain degree of atypia. These results suggest that atypical skin fibroma in the Djungarian hamster is an androgen-dependent tumor and originates from skin GL cells.

Subungual pleomorphic fibroma

BACKGROUND

Pleomorphic fibroma is a benign fibroblastic tumor characterized by pleomorphic, hyperchromatic cells or giant multinucleated cells embedded in a collagenous stroma. These cytologic features may lead to an incorrect diagnosis of malignancy. Most cases reported in the literature are located on trunk or extremities; the presentation as a subungual mass is rare.

METHODS

We report an unusual case of a subungual pleomorphic fibroma in 66-year-old woman. Clinical information was obtained. Histologic examination and immunohistochemical studies were performed.

RESULTS

A 66-year-old woman presented with a longstanding (40 years), subungual mass that deformed the nail of the left middle finger. Microscopic examination revealed a paucicellular tumor composed of hyperchromatic spindled, pleomorphic, floret-like giant cells embedded in haphazardly arranged collagen bundles in the dermis. No mitotic figures were seen. The tumor cells were vimentin-positive but did not stain with antibodies to S-100, cytokeratin, smooth muscle actin, factor XIIIa or CD34 negative. The diagnosis of a pleomorphic fibroma was made. Follow-up shows no evidence of tumor, 36 months after excision.

CONCLUSION

Pleomorphic fibroma of the subungual region is an unusual cutaneous tumor with histologic features that may cause confusion with true sarcomas. This is only the second case reported of a subungual pleomorphic fibroma. Pleomorphic fibroma should be considered in the differential diagnosis of pleomorphic subungual tumors.

Ossifying fibromyxoid tumour of soft parts, with focus on unusual clinicopathological features

AIMS

Ossifying fibromyxoid tumour is a rare lesion that generally occurs in the soft tissues of proximal limbs/girdle, or head and neck. Histologically, it usually consists of bland, mitotically inactive, S100+ cells in a fibromyxoid matrix with a characteristic peripheral ossification. However, we present two cases that deviated from this pattern.

MATERIAL AND METHODS

One tumour, which was removed from the axilla of a 55-year-old female, was unusual in its large size (120 mm in diameter) and in its restriction of bone formation to its central zones. The other tumour, which occurred in a 62-year-old female, was remarkable in its acral location on the hand and high mitotic activity (four mitoses per high-power field). These features caused concern and follow-up of the patients was recommended. So far there have been no recurrences (25 and 18 months after surgery, respectively). An additional previously undescribed feature was the presence of fibronexus-like structures by electron microscopy in the second case. However, a myofibroblastic phenotype was not supported by the immunohistochemical findings.

CONCLUSION

Though a distinct entity, ossifying fibromyxoid tumour may exhibit a wider clinicopathological spectrum than generally recognized.

Juvenile hyaline fibromatosis: a case report

Juvenile hyaline fibromatosis (JHF) is a rare disease with autosomal recessive inheritance. It is characterized by papulonodular skin lesions which are painless but cosmetically unacceptable, and often disturb normal joint function. The nose, chin, ears, scalp, back, and knees are the most common affected sites. In some cases, gingival hypertrophy, flexion contractures of the large joints, osteolytic bone lesions, and stunted growth may be associated with skin lesions. We report a 9-year-old girl presented with a soft, painless, slow growing, tumoral mass on the supratip of her nose. The lesion was totally excised with open rhinoplasty approach and histopathological diagnosis was JHF.

Basic FGF and Ki-67 proteins useful for immunohistological diagnostic evaluations in malignant solitary fibrous tumor

Solitary fibrous tumor (SFT) is an uncommon soft tissue tumor initially reported in the pleura but recently described in other sites in the body. Morphological distinction between benign and malignant SFT is often difficult. An immunohistochemical study was performed in pleural and extrapleural sites. The aim of this study was to determine if an immunohistochemical method is helpful in distinguishing benign SFT from malignant SFT, and providing valid information to predict the prognosis associated with malignant SFT. Twenty-four cases of benign (14 patients) and malignant (10 patients) SFT in the pleura, pelvic space, prostate and other sites of soft tissue were analyzed. Tumors from 10 patients were diagnosed as malignant on the basis of markedly increased cellularity, mitotic activity (>4/10 high-power fields), nuclear pleomorphism and areas of necrosis. Immunohistochemically, we found a mean basic fibroblast growth factor (bFGF) labeling index of 48.67% (48.67 +/- 8.52%) for benign SFT and 74.5% (74.5 +/- 6.92%) for malignant SFT (P < 0.05). We also found a mean Ki-67 labeling index of 1.9% (1.9 +/- 0.43%) for benign SFT and 6.11% (6.11 +/- 1.05%) for malignant SFT (P < 0.05). Our results suggest that bFGF and Ki-67 are diagnostically relevant to the evaluation of malignant SFT and these proteins are thought to be potentially useful markers for prognosis of SFT.

In vitro and in vivo expression of somatostatin receptors in intermediate and malignant soft tissue tumors

BACKGROUND

Previous studies showed that the subtype 2 of somatostatin receptors (sstr2) is generally expressed by soft tissue sarcomas.

MATERIALS AND METHODS

Using reverse transcription-polymerase chain reaction (RT-PCR), the present study evaluated the expression of sstr mRNA in 31 human intermediate and malignant soft tissue tumors. In 8 patients somatostatin receptor scintigraphy was performed to detect soft tissue tumor sites and visualize in vivo sstr expression.

RESULTS

Somatostatin receptors were identified in 84% of the tumors analyzed by RT-PCR analysis. sstr1 and sstr2 were the receptors most frequently detected. Somatostatin receptor scintigraphy was able to identify primary and/or metastatic sites in 7 out of 8 patients, with an overall sensitivity per site of 87%. Concordant results were found between in vitro and in vivo techniques.

CONCLUSION

The wide expression of sstrs in soft tissue tumors suggest a relevant role for these receptors in diagnosis and may have therapeutic applications.

Elastofibromatous polyp of the sigmoid colon--a case report and review of gastrointestinal elastofibromas

Elastofibromatous change in the gastrointestinal tract is a rarely reported, usually polypoid lesion of unknown etiology with submucosal stromal change that may mimic amyloid deposition. The constituent amorphous material of the polyp stroma has distinctive features that permit an accurate assessment and diagnosis including: distribution of the material predominantly in the submucosa; distinctive fibrillar and granular appearance of the deposits; thick, irregular, haphazardly arranged bundles of elastic fibres positive for Verhoeff's elastic stain; ultrastructural fibres with an electron dense curvilinear or beaded appearance; lack of amyloid type vascular wall deposits; and lack of amyloid congophilia or crystal violet metachromasia. The clinical, light microscopic, histochemical and ultrastructural characteristics of this deposited material are reviewed in detail in the present report of a patient who presented with an asymptomatic polypoid lesion of the sigmoid colon. Other reported cases are summarized, and their clinical and pathological features are compared with the current case.

Calcospherules associated with juvenile hyaline fibromatosis

Juvenile hyaline fibromatosis is a rare autosomal recessive genodermatosis that manifests with 1 to 5 cm skin tumors, gingival hyperplasia, osteolytic bone lesions, and joint contractures. The skin tumors are most often located on the head and periarticular extremities. A case of juvenile hyaline fibromatosis with typical skin tumors that on biopsy exhibited basophilic calcospherules is presented. Although noted in a single case, these structures may be a novel, yet helpful, diagnostic marker.

July 2002: 66-year-old female with a one-year history of progressive left proptosis

The July 2002 Case of the Month (COM). This 66-year-old Caucasian female presented with gradually increasing protrusion of her left eye over a one-year period. She complained of increased tearing and foreign body sensation. The physical examination revealed a visual acuity of 20/20, normal color testing, full vision field with motility of her left eye limited in lateral gaze. Pupils were round, symmetric, with no afferent pupillary defect noted. On external examination, her left eye was grossly proptotic with resistance to retropulsion. She had 4 mm proptosis of the left eye. Computed tomography and MR imaging demonstrated a left retro-orbital mass with gadolinium enhancement and focal remodeling of orbital bones. She underwent surgical resection of tumor with a diagnosis of solitary fibrous tumor, and postoperatively she was symptom free. The histopathological differential diagnoses of spindle cell neoplasms of the orbit are discussed. Five months after surgery, no evidence of tumor recurrence was seen on neuroimaging and her vision was 20/20.

Immunohistochemical comparison of gastrointestinal stromal tumor and solitary fibrous tumor

CONTEXT

The differential diagnosis of gastrointestinal stromal tumors (GIST) and solitary fibrous tumors (SFT) may be a diagnostic challenging because of overlapping clinicopathologic features. Many studies have shown consistent immunoreactivity for CD117 (c-Kit) in GIST. However, only a few studies have evaluated CD117 expression in SFT, and these studies have used an antibody from Santa Cruz Biotechnology. In non-GIST lesions, reactivity with this antibody has been shown to differ from that with a CD117 antibody from Dako Corporation. The immunoreactivity of SFT with the Dako CD117 antibody has not been reported. Conversely, CD99 is a marker for SFT, and its expression in GIST has not been evaluated.

OBJECTIVE

To study the immunohistochemical profiles of GIST and SFT to evaluate their diagnostic overlap.

DESIGN

We studied the immunoreactivity of 27 unequivocal GIST and 19 unequivocal extra-abdominal SFT for CD117, CD34, CD99, alpha-smooth muscle actin, vimentin, CD31, S100 protein, and muscle-specific actin. All antibodies, including CD117, were from Dako Corporation.

RESULTS

We found positive immunoreactivity for CD117 in 100% of GIST and none of SFT; for CD34 in 89% of GIST, and 100% of SFT; for CD99 in 89% of GIST and 100% of SFT; for alpha-smooth muscle actin in 48% of GIST and 31% of SFT; for vimentin in 89% of GIST and 90% of SFT; and for muscle-specific actin in 22% of GIST and none of SFT. None of the GIST or SFT showed immunoreactivity for CD31 and S100 protein.

CONCLUSIONS

The major difference between GIST and SFT was strong CD117 immunoexpression in all GIST and an absence of this expression in all SFT. With the exception of muscle-specific actin, the prevalence of immunoreactivity for the markers studied did not differ substantially between these 2 tumors. We conclude that GIST and SFT show distinctly divergent immunoprofiles with respect to CD117 and muscle-specific actin.

The gene for juvenile hyaline fibromatosis maps to chromosome 4q21

Juvenile hyaline fibromatosis (JHF) is an autosomal recessive condition characterized by multiple subcutaneous nodular tumors, gingival fibromatosis, flexion contractures of the joints, and an accumulation of hyaline in the dermis. We performed a genomewide linkage search in two families with JHF from the same region of the Indian state of Gujarat and identified a region of homozygosity on chromosome 4q21. Dense microsatellite analyses within this interval in five families with JHF who were from diverse origins demonstrate that all are compatible with linkage to chromosome 4q21 (multipoint LOD score 5.5). Meiotic recombinants place the gene for JHF within a 7-cM interval bounded by D4S2393 and D4S395.

Beta-catenin immunohistochemistry separates mesenteric fibromatosis from gastrointestinal stromal tumor and sclerosing mesenteritis

Although separating gastrointestinal stromal tumor (GIST) from mesenteric fibromatosis and sclerosing mesenteritis is clinically important, this distinction sometimes poses problems for practicing pathologists. In the STI571 (Gleevec, Imatinib) era, the problem may be further compounded when protocol-driven staining for CD117 (c-kit) is performed on spindle cell proliferations presenting in the bowel wall and mesentery using an antibody known to react with the majority of mesenteric fibromatoses when other antibodies are more specific. Because most mesenteric fibromatoses have mutations in the pathway and hence have abnormal nuclear accumulation of beta-catenin protein, we studied beta-catenin expression among a panel of other immunohistochemical stains to distinguish mesenteric fibromatosis, GIST, and sclerosing mesenteritis. Examples of gastrointestinal stromal tumors (GIST, 11), sclerosing mesenteritis (5), and mesenteric fibromatosis (10) were retrieved from the archives of our institutions. Cases were studied with an immunohistochemical panel consisting of CD117, beta-catenin, CD34, smooth muscle actin, desmin, keratin, and S-100 protein. Cases were scored as "negative," "focally positive," or "diffusely positive." In evaluating beta-catenin, nuclear accumulation was required. GIST all had CD117 (11 of 11, diffuse) and CD34 (11 of 11, diffuse) with variable actin (5 of 11, focal) and negative desmin, keratin, S-100 protein. All GIST lacked beta-catenin (0 of 11). Mesenteric fibromatosis had CD117 (6 of 10, 3 focal, 3 diffuse), typically expressed more weakly than in GIST, actin (5 of 9, focal), and desmin (3 of 8, focal) in keeping with myofibroblastic differentiation but lacked CD34, S-100, and keratin. CD117 staining was not eliminated by use of a non-avidin-biotin technique. Nuclear beta-catenin was detected in 9 of 10 fibromatoses, including one case associated with familial adenomatous polyposis. Two of five sclerosing mesenteritis cases focally expressed CD117. None of the sclerosing mesenteritis cases had nuclear beta-catenin. Sclerosing mesenteritis cases were otherwise fibroblastic and myofibroblastic with focal actin in 5 of 5 and negative desmin, keratin, and S-100 protein but one had CD34 (1 of 5, focal). With increasing protocol-driven interest in evaluating bowel wall and mesenteric spindle cell lesions using CD117 (c-kit) antibodies, it is important for practicing pathologists to be aware that lesions other than GISTs are likely to express this antigen using certain antibodies. beta-Catenin staining identifies lesions that are, instead, mesenteric fibromatoses.

Expression of collagen type II, S100B, S100A2 and osteocalcin in chondroblastoma and chondromyxoid fibroma

Chondroblastoma and chondromyxoid fibroma (CMF) has been investigated in numerous histological studies, but its biological nature and histogenetic origin are still a matter of debate. We evaluated the expression of type II collagen, S100A2, S100B, and osteocalcin to study the matrix biochemistry and phenotype of the neoplastic cells in these tumors. Immunohistochemically, the expression of type II collagen was diffuse in 15 cases (75%) among total 20 chondroblastomas and 12 (85.7%) among total 14 CMFs. The expression of S100B was also diffuse in all cases (100%) of chondroblastomas and 12 cases (85.7%) of CMFs. We were able to obtain the expression of S100A2, focally. The expression of osteocalcin was focally noted in 18 cases (90%) of chondroblastomas and 8 cases (57.1%) of CMFs. In conclusion, our data support that chondroblastoma and CMF are a distinct tumor entity with the basic expression of chondroid markers. But these tumors also show histologic diversity with focal co-expression of osteoid markers.

Expression of ALK1 and p80 in inflammatory myofibroblastic tumor and its mesenchymal mimics: a study of 135 cases

Abnormalities of chromosome 2p23 with expression of ALK1 and p80 occur in both inflammatory myofibroblastic tumor (IMT) and anaplastic large cell lymphoma. This immunohistochemical study investigates whether the ALK family of neoplasms includes fibroblastic-myofibroblastic, myogenic, and spindle cell tumors. Formalin-fixed paraffin-embedded archival tissues from 10 IMTs and 125 other soft tissue tumors were stained for ALK1 and p80 with standard immunohistochemistry. ALK1 and/or p80 reactivity was observed in a cytoplasmic pattern in IMT (4/10; 40%), malignant peripheral nerve sheath tumor (4/10; 40%), rhabdomyosarcoma (6/31; 19%), leiomyosarcoma (1/10; 10%), and malignant fibrous histiocytoma (1/11; 9%). No staining was observed in nodular fasciitis, desmoid, infantile myofibromatosis, infantile fibrosarcoma, synovial sarcoma, leiomyoma, or myofibrosarcoma. Alveolar rhabdomyosarcomas (4/16; 25%) displayed a distinctive dot-like cytoplasmic positivity. No cases displayed nuclear reactivity. Fluorescent in situ hybridization on 12 of the positive cases revealed a combination of abnormalities including ALK break-apart signals, nucleophosmin (NPM)/ALK fusions, or extra copies of 2p23. This study demonstrates that in addition to IMT, abnormalities of ALK1 and p80 expression with a variety of structural chromosomal changes are found in several sarcomas, especially rhabdomyosarcoma and malignant peripheral nerve sheath tumor. Although immunoreactivity in non-IMTs cannot distinguish between structural abnormalities involving 2p23 or additional copies of 2p23, it supports the concept of ALK involvement in a larger group of neoplasms, some of which have other documented clonal abnormalities. In IMT, immunohistochemistry for ALK1 and p80 is useful as an indicator of a 2p23 abnormality, but it must be interpreted in the context of histologic and other clinicopathologic data if used as an adjunct to differential diagnosis.

Stromal sarcoma of the breast with leiomyosarcomatous pattern

We report an unusual case of stromal sarcoma of the breast with leiomyosarcomatous pattern, which recurred locally and was finally treated by radical mastectomy. The tumor was composed of pleomorphic and hyperchromatic spindle-shaped cells arranged in an interdigitating fascicle. The nuclei were of moderate to severe atypia. An average of 10 mitoses per 10 high-power fields was seen. Immunohistochemically, the stromal cells were positive for vimentin and alpha-smooth muscle actin, but negative for S-100 protein, cytokeratin and desmin. The average Ki-67 (MIB1) labeling index in the stromal cells was 34%. Electron microscopic evaluation revealed further evidence of smooth muscle differentiation; stromal cells had frequently indented nuclei, well-developed rough endoplasmic reticulum, thin basal lamina and dense patch-like structures within the cytoplasm. Analysis of previous literature on 17 cases reveals mitotic activity of the tumor seemingly of little prognostic value. This case indicated difficulty in diagnosing leiomyosarcoma. The risk of local recurrence remains even if the surgical margin is free of tumor cells.

Ultrastructural and immunohistochemical characterization of the so-called giant multinucleate cells in cutaneous collagenomas

AIMS

This study was undertaken to compare the histopathological, immunohistochemical and ultrastructural features of the so-called giant multi nucleate cells in cutaneous collagenomas: giant-cell collagenoma and solitary sclerotic fibroma.

METHODS AND RESULTS

We studied four collagenomas: one giant-cell collagenoma and three solitary sclerotic fibromas. All the cases showed an indolent clinical presentation and were histologically constituted by a well-demarcated dome-shaped proliferation of coarse collagen bundles with a varying number of interspersed giant multinucleate cells and stellate mononuclear cells. The immunohistochemical study on paraffin sections revealed that neoplastic cells in both collagenomas were vimentin and CD34-positive, whereas FXIIIa was only expressed in solitary sclerotic fibromas. In regard to the so-called giant multinucleate cells, we have ultrastructurally found that these cells were 'real' multinucleate cells in giant-cell collagenoma, whereas in solitary sclerotic fibromas they consisted of closely packed aggregates of individual stellate mononuclear cells. Moreover, perinuclear cisternae focally containing finely textured material of moderate density were unexpectedly found in giant cells of giant-cell collagenoma, a finding which was not observed in solitary sclerotic fibromas. Additionally, a characteristic cell-cell interaction between tumour cells and mast cells was encountered in all collagenomas.

CONCLUSIONS

This study supports a distinctive immunohistochemical and overall ultrastructural profile of giant multinucleate cells in giant-cell collagenoma and solitary sclerotic fibroma, which suggests a different pattern of differentiation for these two related cutaneous lesions.

h-Caldesmon as a specific marker of smooth muscle cell differentiation in some soft tissue tumors of the skin

BACKGROUND

An existing problem in contemporary pathology is the classification and distinction of spindle cell soft tissue tumors of the skin. Markers such as alpha-smooth muscle actin (alpha-SMA) and desmin, considered specific for smooth muscle cell (SMC), have been shown to be expressed in a variety of fibroblastic and myofibroblastic processes. High-molecular-weight caldesmon (h-caldesmon), one of two isoforms, is reported to be expressed exclusively by SMC and has recently been shown to be a specific marker of SMC tumors.

METHODS

Tumors were obtained from 11 patients taken from the surgical pathology archives of the University of South Florida and cases were coded as smooth muscle hamartoma, myofibroma, and dermatomyofibroma.

RESULTS

The case of smooth muscle hamartoma had greater than 90% of tumor cells labeling with anti-h-caldesmon antibodies. Three of three cases of myofibroma had focal areas of positivity representing less than 10% of total tumor cells. Seven of seven dermatomyofibromas showed no apparent labeling with anti-h-caldesmon antibody. Dense reactivity was noted in vascular wall smooth muscle, indicating internal controls.

CONCLUSIONS

We can conclude that h-caldesmon is a specific marker of fully differentiated smooth muscle and that it can serve to differentiate spindled SMC soft tissue tumors of the skin from tumors of myofibroblastic and/or fibroblastic origin.

Orbital solitary fibrous tumor with aggressive behaviorThree cases and review of the literature

BACKGROUND

Solitary fibrous tumor (SFT) is a rare spindle cell tumor that arises most often in the visceral pleura; however, a review of the literature shows at least 31 cases occurring in the orbit.

METHODS

A retrospective case series of three patients with orbital SFT: a 50-year-old man, observed in 1997, with an angioma-like lesion in the upper half of the orbit causing osteolysis of the orbital roof; a 24-year-old man, observed in 1992, with a superotemporal mass in the right orbit occupying the lacrimal gland region, firstly diagnosed as schwannoma, recurring 4 years after dacryoadenectomy; a 70-year-old man, with a retrobulbar mass diagnosed on a biopsy as hemangiopericytoma, recurring and infiltrating the orbital roof 4 years after surgery.

RESULTS

A review of the literature and presentation of three cases of SFT which showed infiltration of the orbital roof and/or recurrence.

CONCLUSIONS

Our cases provide evidence of how orbital SFT can behave aggressively and mimic other orbital tumors, thus making mandatory the consideration of this relatively new entity in common clinical practice as well as careful follow-up. Their aggressive growth is unusual, described in only 6 of the 31 cases so far reported in the literature. Immunohistochemistry is of importance for the diagnosis, since CD34 immunoreactivity is peculiar to SFT.

Calcifying fibrous 'pseudotumor': clinicopathologic study of 15 cases and analysis of its relationship to inflammatory myofibroblastic tumor

Calcifying fibrous pseudotumor (CFP) has been postulated to be a "late" stage of inflammatory myofibroblastic tumor (IMT). We analyzed 15 cases (8 females and 7 males; aged 1 to 65 years). The anatomic distribution was wide, including 3 cases each in neck, mesentery/omentum, and GI tract and 2 cases each in mediastinum and paratesticular sites. Follow-up information was available in 10 patients (range 4 to 228 months). Local recurrence occurred in 3 patients and was repeated in 2. Tumor size ranged from 0.6 to 25 cm. Lesions were well-circumscribed hypocellular spindle cell proliferations with dense stromal collagen, a lymphoplasmacytic infiltrate, and stromal calcifications. Features of conventional IMT were not seen. Immunostaining showed CD34 positivity in most cases as well as rare cells positive for smooth muscle actin and desmin, and consistent negativity for ALK-1 and S-100 protein. These findings suggest that CFP is a distinctive benign mesenchymal neoplasm with a low risk for recurrence and, therefore, best labelled as "calcifying fibrous tumor." There is no convincing evidence to support an association between CFP and IMT.

Participation of alpha-smooth muscle actin-positive cells in renomedullary interstitial cell tumors

Renomedullary interstitial cell tumors are benign lesions which are generally discovered in specimens nephrectomized for other malignant tumors or by autopsy. We examined the histologic features of eight tumors from four patients and investigated the appearance of alpha-smooth muscle actin (ASMA)-positive cells in these tumors using immunohistochemistry. We considered that five tumors are cellular type and the remaining three as fibrous. Characteristic hyalinization was observed in two of the three fibrous tumors. All the tumors except for one fibrous type contained entrapped tubular cells. CD35-positive cells (dendritic cells) and ASMA-positive cells were observed in all the tumors, with a more frequent occurrence in the cellular type than the fibrous type. CD35-negative spindle cells were considered as fibroblasts or activated fibroblasts (myofibroblasts). The number of CD35-positive cells was higher than that of ASMA-positive cells. Additionally, the entrapped tubular cells showed the transition to spindle cells and some of them expressed for ASMA. With double immunohistochemical staining, there were some cells showing positive reactions for both CD35 and ASMA. Furthermore, an ultrastructural examination confirmed the presence of ASMA-positive filaments in the dendritic cells and myofibroblasts. The expression of TGF-beta 1 was observed not only in the tumor cells and the collecting ducts surrounding the tumor but also in the entrapped tubular cells. In addition, the intensity of TGF-beta 1 was stronger in/around the tumor than in the areas distant from the tumor. The positive cells were more numerous in the cellular type than in the fibrous type. In conclusion, ASMA-positive cells appear in renomedullary interstitial cell tumors and some of the cells may originate in dendritic interstitial cells, fibroblasts including myofibroblasts, and entrapped tubular cells. Furthermore, TGF-beta 1 may contribute to the formation of fibrosis in the tumors.

Two cases of supernumerary ovary: one with large fibroma with Meig's syndrome and the other with endometriosis and cystic change

Reports of supernumerary ovaries are rare. We describe two such cases, one with fibroma and the other with endometriosis and cystic change. A large fibroma measuring 17.4 x 12.0 x 7.5 cm in size was found in the supernumerary ovary of the omentum in the first case of a 47-year-old married woman with Meig's syndrome. The second case was associated with endometriosis and cystic change, measuring 11 x 5 x 3 cm in size and located in the upper abdominal cavity. It was attached to the uterus of a 28-year-old pregnant woman who had neither fibroma nor Meig's syndrome. Histologically, corpus albicans and a few primordial germ cells were demonstrated, respectively. A fibroma showing a storiform pattern was found in the first case. The second case had endometriosis and a thin-walled cyst with bleeding and necrosis caused by torsion. Immunohistochemically, desmin, alpha-smooth muscle actin, c-kit, CA125, Na+/K+ATPase, overexpression of p53, myc and ras were all negative in the fibroma cells of the first case, and in the endometriosis and cyst wall of the second case. The fibroma cells were positive for vimentin and estrogen receptor, and the proliferating cell nuclear antigen was sporadically demonstrated in their nuclei. The mutation of the p53 gene at exons 5-8 was not detected by sequence analysis. Using RT-PCR, bax, bcl-2 and p16 were not detected either. Clinically, the two cases presented here did not show abnormal hormonal symptoms. They were diagnosed as abdominal tumors or masses. Based on these considerations, one might assume that supernumerary ovaries are probably more frequent than reported at present.

Juvenile hyaline fibromatosis: morphologic, immunohistochemical, and ultrastructural study of three siblings

Juvenile hyaline fibromatosis (JHF) is a rare hereditary disease characterized by the deposition of hyaline ground substance, which is described as fibrillogranular material on electron microscopy. Approximately 65 cases have been reported to date in the English language literature. We add 3 new cases of children presenting with multiple subcutaneous nodules. We have described the light microscopic, electron microscopic, and immunohistochemical features of these nodules. The characteristic chondroid appearance on light microscopy is imparted by large peripheral vesicles in the stromal cell cytoplasm. Ultrastructurally, the fibroblasts have shown evidence of defective synthesis of collagen, which is then deposited as fibrillogranular material in the matrix. Immunohistochemical studies have shown CD68+ macrophages and multinucleated histiocytic giant cells in all five specimens from our 3 cases. As far as we know, the presence of giant cells has not been reported in the literature. The main purposes of this report are to highlight the presence of macrophages as a constant constituent of the stromal cells in JHF and to review the literature on this subject.