Calcifying aponeurotic fibroma: a case report and review of literature

Calcifying aponeurotic fibroma is a rare soft tissue tumor that primarily occurs in children and adolescents and has a strong predilection for the distal portion of the extremities, especially the hands and feet. This paper presents a case report of calcifying aponeurotic fibroma.     

Childhood fibrous tumor with psammoma bodies. Clinicopathologic features in two cases

A fibrous tumor with psammomatous calcifications and lymphoplasmacytic cell infiltrate occurred in two children. It could represent a distinctive lesion or late stages of calcifying aponeurotic fibroma, or inflammatory pseudotumor.     

Fibrous hamartoma of infancy: a clinical pathological analysis of seventeen cases

To discuss the clinical and pathological features, differential diagnosis and prognosis of fibrous hamartoma of infancy (FHI), seventeen FHI specimens were analyzed with H&E staining and strepavidin peroxidase (SP) immunohistochemistry to detect distinguishing tissue markers. The long-term outcomes of select cases were also obtained. Among the 17 patients (13 males, 4 females, average age 16 months), FHI manifested as a subcutaneous painless mass, primarily on the back of the neck, the upper arms and buttocks. One recurrence was noted among six follow-up cases. The tumors consisted of three main components: fibrous connective tissue; mature fat; and undifferentiated mesenchymal tissue. Immunohistochemistry revealed that fibrous connective tissue was positive for SMA and actin, mature fat tissue was positive for S-100 protein, and undifferentiated mesenchymal tissue was positive for CD34 and was partially positive for actin and SMA. The tumors were negative for desmin, NSE, bcl-2, β-catenin and Ki-67. In brief, FHI is a benign, fibroblastic/myofibroblastic proliferative lesion. Defined histologic features of FHI as presented here would distinguish FHI from similar invasive tumors including infant fibromatosis, calcifying aponeurotic fibroma, fibrous fatty tumor and embryonal rhabdomyosarcoma. Once clearly identified, FHI is curable with complete resection.     

钙化性纤维性肿瘤4例临床病理学分析

目的 探讨钙化性纤维性肿瘤(calcifying fibrous tumor,CFT)的病理形态学特点、免疫组化表达及鉴别诊断.方法 对4例CFT进行免疫组化检测并文献复习.结果 本组患者年龄19～33岁,发病部位分别为胃、纵膈、大网膜及肠系膜根部.镜下可见在大量胶原化的纤维组织内伴有钙化或砂砾体形成,淋巴细胞、浆细胞散在浸润.免疫组化标记瘤细胞表达vimentin,而CD117、CD34、CD99、desmin、S-100蛋白、SMA、actin、NFP、ALK1、ER、PR、CK、BCL-2及Ki-67均阴性.结论 CFT是一种极少见的良性纤维性肿瘤,其诊断需要结合年龄、组织学形态及免疫组化等特点,还需与钙化性腱膜纤维瘤、钙化性肉芽肿、纤维瘤病、胃肠道间质瘤、炎性肌纤维母细胞瘤、结节性筋膜炎和淀粉样瘤等相鉴别.     

The fibromatoses. An ultrastructural study of 31 cases

During a five year period, thirty one cases of fibromatoses were studied with electron microscopy. A special survey was performed in relation with the proliferating cell, the extracellular space and the morphologic features of some peculiar entities as: juvenile aponeurotic fibroma, nasopharyngeal angiofibroma, recurring digital fibroma of infancy and the group of proliferative fasciitis-myositis. The main conclusions drawn of this study are: the myofibroblast is the proliferating cell of these lesions; those cells are actively synthesizing native and fibrous long spacing collagen; there are frequent intracytoplasmic inclusions of fibrous long spacing collagen; the cytoplasmic inclusions of recurring digital fibroma of infancy correspond to modifications of the cytoskeleton; and, the ganglion-like cells of proliferative fasciitis-myositis are modified myofibroblasts.     

Calcifying fibrous tumor: an unrecognized IgG4—related disease?

Calcifying fibrous tumor is a rare benign mass lesion characterized by bland spindle cells embedded in abundant collagenous matrix, interspersed dystrophic or psammomatous calcifications, and lymphoplasmacytic infiltrate. It shares several clinical and morphologic features with IgG4‐related disease, a newly recognized fibroinflammatory disorder. Characteristic histologic features of IgG4‐related lesions include dense fibrosis and abundant lymphoplasmacytic infiltrate, similar to calcifying fibrous tumor. They contain high numbers of IgG4‐positive plasma cells in the tissue. Patients also often have elevated serum IgG4 levels. We report the case of a patient with an ileal calcifying fibrous tumor that contained 69 IgG4‐positive plasma cells per high‐power field and an IgG4‐to‐IgG ratio of 56% in lesional plasma cells. The patient's serum IgG4 level was 185 mg/dL, more than double the normal value. Altogether, these features suggest that calcifying fibrous tumor could be an unrecognized lesion of IgG4‐related disease.     

Benign pulmonary lesions that may be misdiagnosed as malignant

Five benign pulmonary lesions that may be misdiagnosed as malignant tumors are reviewed. In three lesions, diagnostic problems arise when a spindle cell component is dominant and obscures other characteristic histologic features. In the inflammatory pseudotumor, correct diagnosis relies on recognition of the benign cytology of the spindle cells and identifying a typical admixture of plasma cell-rich inflammatory cells. For spindle cell carcinoids, useful diagnostic features are the organoid pattern, benign cytology, and neuroendocrine differentiation features of the spindle cells. Localized pleural mesothelioma (fibroma) is composed of benign spindle cells in a fibrocollagenous background; mesothelial differentiation is not present by ultrastructural or immunocytochemical analysis. In sclerosing hemangioma, a complex histology may suggest a number of malignancies. Observation of solid and papillary areas of benign tumor cells, as well as sclerosis of vessel walls and intervening areas, will allow correct diagnosis. Pseudolymphoma, a nodular benign lymphoid infiltrate, is distinguished by its polymorphous and polyclonal composition and numerous germinal centers.     

牙源性钙化囊性瘤临床病理研究

目的探讨牙源性钙化囊性瘤(calcifying cystic odontogenic tumor,CCOT)的临床病理分型对治疗预后的影响。方法对39例CCOT的临床表现、X线影象、病理特征及治疗随访资料等进行回顾性分析。结果 39例中男性26例,女性13例,平均年龄29.6岁;病变位于下颌骨21例,上颌骨18例;临床多以颜面部肿胀就诊。X线主要表现为颌骨内界限清楚的放射透光区,单房或多房,其中伴有钙化斑点或团块。镜下均可见到特征性的影细胞,可分为4种类型:单纯囊肿型(17例)、CCOT伴牙瘤型(12例)、CCOT伴成釉细胞瘤增生型(7例)、CCOT伴其他良性牙源性肿瘤型(3例:伴成釉细胞纤维瘤2例,伴成釉细胞纤维牙瘤1例)。治疗均采用囊肿摘除术或刮治术,获得随访33例,复发6例,其中3例复发者均为CCOT伴成釉细胞瘤增生型且有囊壁内浸润(1例复发为牙源性影细胞瘤,1例20年后复发恶变为牙源性影细胞癌)。结论 CCOT伴成釉细胞瘤增生且有囊壁内浸润型行单纯囊肿摘除术或刮治术容易复发,可形成牙源性影细胞瘤或恶变成牙源性影细胞癌,此型肿瘤的手术范围应适当扩大并进行长期随访。     

A calcifying fibroma of the meninges report of a case and review of the literature

We report an unusual tumor related to the meninges designated as a calcifying fibroma of the meninges. Our patient was a 44-year-old man.The tumor was located in the right frontotemporoparietal region and was excised totally via a right frontotemporoparietal craniotomy. The patient had recovered completely, and no recurrence was observed in a follow-up period of three years. Histopathologically, we noted scattered spindle cells among the hyalinized collagenous stroma, dystrophicpsammomatous calcifications, abundant perivascular hyalinization and cartilagenous metaplasia. Immunohistochemically, the tumor cells showed actin, smooth muscle and vimentin immunreactivities. Ultrastructurally, spindle cells showed fibroblastic features. The lesion is a true tumor and it should be kept in mind in the differential diagnoss of meningeal calcifying lesions.     

Odontogenic fibroma

The odontogenic fibroma is a rare tumor that has generated controversy, perhaps disproportionately to its importance in the family of odontogenic tumors. The clinical and radiographic features are well documented but the histologic aspects have generated controversy. The behavior is benign, and published accounts indicate a low recurrence rate following treatment by curettage. The tumor recognized by the World Health Organization (WHO) is the legitimate odontogenic fibroma. Histologic variants include the granular cell type and the hybrid odontogenic fibroma giant cell-like tumor. Although the extraosseous "peripheral" odontogenic fibroma presents as a gingival enlargement clinically indistinguishable from other gingival lesions, its histomorphology is similar to the central tumor. A normal dental follicle around the crown of an unerupted tooth may histologically mimic the odontogenic fibroma and other odontogenic tumors.     

Juvenile aponeurotic fibroma: an ultrastructural study

The light and electron microscopic findings in a case of juvenile aponeurotic fibroma are described. The tumor was composed of fibromatosislike areas and cartilagelike islands with characteristic calcification. The ultrastructural study verified the cartilaginous nature of this tumor. The cartilagelike islands were made up of chondrocytic cells embedded in an abundant intercellular matrix containing fine fibrils, spherical granules, and pleomorphic membrane-bound vesicles. The chondrocytic cells had many microvilli, a well-developed granular endoplasmic reticulum, and a prominent Golgi complex. In the periphery of each cartilagelike island was a perichondriumlike structure exhibiting transitional features from fibroblastic cells to chondrocytic cells. The fibromatosislike areas consisted of spindle-shaped fibroblastic cells and occasional myofibroblasts. The morphologic pattern of the tumor somewhat mimics embryonal chondrogenesis, and the fibromatosislike areas may represent an overgrowth of the fibrous layer of the perichondrium. It is possible to regard this tumor as an organoid tumor having a capacity for bidirectional differentiation into cartilage and fibrous tissue.     

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.     

Pigmented ameloblastic fibrodentinoma: a novel melanin-pigmented intraosseous odontogenic lesion

This paper reports about an ameloblastic fibrodentinoma with macroscopically visible pigmentation, resulting in the clinical appearance of a melanotic lesion in a 21-year-old Japanese male. In addition to the characteristic histopathologic features of ameloblastic fibrodentinoma, various-formed and -sized cells, which were considered to be melanophages containing numerous aggregates of melanin pigment in their cytoplasm, were densely distributed throughout the mesenchymal component. In addition, melanin pigment was deposited in dentin. Some of the pigmented cells showed dendritic form and were regarded as melanocytes. Furthermore, pigmented cells were frequently distributed in the epithelial component, and melanin pigment was seen in some epithelial cells. Perusal of the English language literature revealed 30 cases of pigmented odontogenic tumors: 18 were calcifying odontogenic cysts, three were ameloblastic fibro-odontomas, three were adenomatoid odontogenic tumors, two were odontomas, one was an ameloblastic fibroma and one was an odontogenic fibroma. However, all of these reported lesions did not show macroscopically visible pigmentation. The possible histogenesis of melanocytes in the odontogenic lesions is discussed, although no firm conclusion could be drawn. Received: 13 January 2000 / Accepted: 27 March 2000     

Desmoplastic fibroma of the rib: two case reports

Desmoplastic fibroma is a very rare primary tumor of bone, closely related to aggressive fibromatosis of soft tissue. Although considered a benign lesion, it can be very aggressive locally and has a high rate of local recurrence after incomplete surgical excision. Radiologically, the lesion shows no distinctive features, often simulating osteosarcoma, fibrous dysplasia, or fibrosarcoma. Rib involvement by desmoplastic fibroma is extremely rare. We present two cases of desmoplastic fibroma involving this unusual location with lytic costal lesion and chest wall extension. Histological examination after surgical resection revealed that the tumor consisted of spindle cells with small, elongated nuclei in a background of numerous collagen fibers and infiltrating lamellar bone. There was no evidence of nuclear atypia, mitotic activity, or necrosis. We also discuss histological differential diagnosis as well as clinical features and the radiological and pathologic findings of this rare disease. Recognition of this entity is important to ensure proper surgical treatment.     

Desmoplastic fibroma of bone with extensive cartilaginous metaplasia

Desmoplastic fibroma of bone is a rare tumor demonstrating the same histologic and biologic features of its soft tissue counterpart, aggressive fibromatosis. We report the second case of desmoplastic fibroma of bone with extensive chondroid metaplasia. The tumor arose in the left ischium of a 51-year-old male, with extension into adjacent musculature as a pseudoencapsulated mass. The infiltrating growth and quality of the fibrous component are characteristic of desmoplastic fibroma, and in addition, abrupt transitions into bland hyalin cartilage were frequent. Discriminating features of this lesion from other bone tumors capable of biphasic expression of fibrous and chondroid elements are discussed.     

Chondromyxoid fibroma: a tumor showing myofibroblastic, myochondroblastic, and chondrocytic differentiation.

Chondromyxoid fibroma (CMF) is a rare primary benign tumor of bone that demonstrates variable histologic features and is often confused with chondrosarcoma. Although the chondroid elements in CMF have been reported to be S-100 protein positive and to have chondrocytic features ultrastructurally, the immunohistochemical and ultrastructural profile of CMF, especially with respect to the peripheral nonchondroid elements, has not been extensively studied. Formalin-fixed, paraffin-embedded tissue from 10 CMFs were stained immunohistochemically with antibodies to vimentin, desmin, muscle actin, smooth muscle actin, S-100 protein, and CD34. Six tumors were also examined ultrastructurally. The chondroid areas showed variable staining for S-100 protein but did not stain for muscle actin or smooth muscle actin. The peripheral areas surrounding the chondroid areas stained diffusely for smooth muscle actin and muscle actin but did not stain for S-100 protein. CD34 highlighted the extensive vascularity that was especially prominent in the peripheral areas; no tumor cells stained for CD34. There was no staining for desmin. Ultrastructural examination showed three different cell types. Some cells showed the classic features of chondrocytes, other cells had the features of myofibroblasts, and the third cell type had the features of both chondrocytes and myofibroblasts ("myochondroblasts"). These findings support the conclusion that CMF is a tumor showing myofibroblastic, myochondroblastic, and chondrocytic differentiation.     

Fibroma of tendon sheath.

A series of nine cases of fibroma of tendon sheath is described including details of the ultrastructural features of two cases. The series was composed of lesions from six males and three females with a mean age of 38 yr. The most common site of involvement was the hand (including fingers) and the mean greater diameter was 19 mm. Typically the tumours were lobulated and microscopically there was a collagenous stroma with spindle and stellate cells in a moderate degree of cellularity. One recurrence was noted in the series. The lesion was distinguished from circumscribed fibromatosis, nodular fasciitis, neurofibroma, leiomyoma, scar tissue, giant cell tumour of tendon sheath (localised nodular tenosynovitis) and fibrous histiocytoma. Ultrastructural studies revealed that the large majority of cells present in the two cases studied were myofibroblasts and fibroma of tendon sheath is therefore the third instance of a benign tumour containing these cells (the other two being dermatofibroma and giant cell fibroma of the oral mucosa).     

Immunohistochemical expression of amelogenins in odontogenic epithelial tumours and cysts

Summary Amelogenins, enamel proteins in odontogenic tumours, were detected immunohistochemically using a monoclonal antibody. They were strongly expressed in amyloid-like material, ghost cells, and the cells surrounding ghost cells of calcifying epithelial odontogenic tumours and cysts, whereas calcified bodies within the tumours and cysts showed negative staining. The expression of amelogenins was also positive in tumour cells of ameloblastoma, adenomatoid odontogenic tumour, squamous odontogenic tumour and ameloblastic fibroma. Peripheral tumour cells of the follicular ameloblastoma were positive with relatively intense staining. Undifferentiated or flattened tumour cells of adenomatoid odontogenic tumour and non-keratinized tumour cells of the squamous odontogenic tumour showed marked staining. Reduced ameloblasts in the odontoma displayed the strongest staining for amelogenins. The study suggests that biosynthesis of amelogenins may occur in the homogeneous materials of calcifying epithelial odontogenic tumours and cysts.     

Desmoplastic spitz nevus: report of a case and review of the literature

Desmoplastic spitz nevus (DSN) is an uncommon melanocytic lesion. The histologic features of this benign tumour may mimic those of certain benign (dermatofibroma and desmoplastic cellular blue nevus) or malignant (metastatic carcinoma and malignant melanoma) neoplasms. We report the case of a male with a DSN, and also review the clinical characteristics, histologic features and differential diagnosis of this extremely rare lesion. The lesion is identified as an asymptomatic reddish-brown dome-shaped papule on the forearm. Microscopic examination showed a symmetric lesion in the dermis. The neoplastic cells were large and epithelioid-shaped, and were either isolated as individual cells or arranged in small nests in a paucicellular hyalinized stroma. Nuclei were large and vesicular with small nucleoli and no mitoses. Diffuse expression of S100 and the absence of staining with antibodies to melan-A and HMB45 was observed. A diagnosis of DSN with free margins was made. The histologic presentation of this benign lesion mimics both benign and malignant neoplasms. The immunohistochemical profile (S100 positive, HMB-45 negative and cytokeratin negative) may be helpful to differentiate it from other lesions.     

Odontogenic cysts, odontogenic tumors, fibroosseous, and giant cell lesions of the jaws.

Odontogenic cysts that can be problematic because of recurrence and/or aggressive growth include odontogenic keratocyst (OKC), calcifying odontogenic cyst, and the recently described glandular odontogenic cyst. The OKC has significant growth capacity and recurrence potential and is occasionally indicative of the nevoid basal cell carcinoma syndrome. There is also an orthokeratinized variant, the orthokeratinized odontogenic cyst, which is less aggressive and is not syndrome associated. Ghost cell keratinization, which typifies the calcifying odontogenic cyst, can be seen in solid lesions that have now been designated odontogenic ghost cell tumor. The glandular odontogenic cyst contains mucous cells and ductlike structures that may mimic central mucoepidermoid carcinoma. Several odontogenic tumors may provide diagnostic challenges, particularly the cystic ameloblastoma. Identification of this frequently underdiagnosed cystic tumor often comes after one or more recurrences and a destructive course. Other difficult lesions include malignant ameloblastomas, calcifying epithelial odontogenic tumor, squamous odontogenic tumor, and clear-cell odontogenic tumor. Histologic identification of myxofibrous lesions of the jaws (odontogenic myxoma, odontogenic fibroma, desmoplastic fibroma) is necessary to avoid the diagnostic pitfall of overdiagnosis of similar-appearing follicular sacs and dental pulps. Fibroosseous lesions of the jaws show considerable microscopic overlap and include fibrous dysplasia, ossifying fibroma, periapical cementoosseous dysplasia, and low-grade chronic osteomyelitis. The term fibrous dysplasia is probably overused in general practice and should be reserved for the rare lesion that presents as a large, expansile, diffuse opacity of children and young adults. The need to use clinicopathologic correlation in assessing these lesions is of particular importance. Central giant cell granuloma is a relatively common jaw lesion of young adults that has an unpredictable behavior. Microscopic diagnosis is relatively straightforward; however, this lesion continues to be somewhat controversial because of its disputed classification (reactive versus neoplastic) and because of its management (surgical versus. medical). Its relationship to giant cell tumor of long bone remains undetermined.