Pleomorphic sclerotic fibroma: a case report and literature review.

Pleomorphic sclerotic fibroma is a benign neoplasm exhibiting features of sclerotic fibroma and pleomorphic fibroma. We report another such case. The tumor presented as a firm, 0.5-cm, flesh-colored papule on the forehead of a 72-year-old white man for an unknown duration. Histologic examination revealed a neoplasm in which the superficial portion showed features of a pleomorphic fibroma, the deeper portion showed features of a sclerotic fibroma, and a transitional area was present in between. We propose that pleomorphic fibroma, sclerotic fibroma, and pleomorphic sclerotic fibroma form a spectrum. Pleomorphic sclerotic fibroma may be used as a broad diagnostic term to encompass the spectrum.     

Pleomorphic fibroma of the skin with MDM2 immunoreactivity: A potential diagnostic pitfall

Pleomorphic fibroma is a rare benign cutaneous neoplasm characterized by spindle‐shaped cells and multinucleated giant cells scattered throughout collagenous stroma. These morphologic features can lead to diagnostic confusion, including atypical lipomatous tumor as one consideration. In contrast to atypical lipomatous tumor, previous studies have found pleomorphic fibroma to be negative for MDM2 immunohistochemical staining and MDM2 gene amplification. Here, we present a case of pleomorphic fibroma of skin with nuclear MDM2 immunoreactivity in the absence of MDM2 gene amplification, underscoring the superiority of fluorescence in situ hybridization as a diagnostic test in this differential diagnosis. The RB1 locus is also explored for differential diagnosis with pleomorphic/spindle cell lipoma and related entities.     

Giant cell collagenoma: case report and review of the literature

BACKGROUND: Giant cell collagenoma (GCC) is a recently described cutaneous fibrous neoplasm that usually affects young to middle-aged adults. Despite its similar histological appearance with circumscribed storiform collagenoma, no association of GCC with Cowden's syndrome has been described so far. To the best of our knowledge only five cases of this rare fibrous tumor have been reported so far. METHODS: We report a case of a 79-year-old male patient presenting with a slow growing flesh-colored dome-shaped lesion in his left forearm, with a clinical diagnosis of fibroma. No stigma of Cowden's syndrome was depicted. RESULTS: The histological analysis showed a symmetrical and well-circumscribed flat-dome-shaped lesion covered by an atrophic overlying epidermis. The neoplasm was composed of hyalinized collagen bundles disposed in a whorled storiform pattern. Admixed with the collagen matrix, there were two distinct cell populations, one composed by spindle-shaped mononuclear cells, and the other composed by bizarre multinucleated giant cells. Immunohistochemical analysis showed positivity for vimentin and actin HHF35 in the mononucleated. The multinucleated cells only immunoexpressed vimentin. CONCLUSION: GCC is an unusual cutaneous fibrous tumor that should be differentiated from circumscribed storiform collagenoma, pleomorphic fibroma, regressive forms of dermatofibroma, and solitary myofibroma based on its histological features.     

Fibroepithelioma of pinkus with tumor giant cells

A case of fibroepithelioma of Pinkus with pleomorphic epithelial giant cells is reported. The lesion was an ovoid polypoid nodule measuring 4 mm x 3 mm x 2 mm and was located close to the right axilla in an 86-year-old woman. The immunohistochemical features of the epithelial giant cells indicate that most of these cells are not cycling. We suggest that these cellular changes may represent a senescent event. Giant cells showed a mean nuclear major diameter more than twice that of small cells. Flow cytometric study of the tumor showed a hypodiploid DNA content and an intermediate grade S-phase fraction of the aneuploid component. To the best of our knowledge, a pleomorphic variant of Pinkus fibroepithelioma has not been reported to date. In fibroepithelioma of Pinkus, the correct diagnosis depends primarily on the architectural pattern of the tumor rather than on its cytologic features.     

HMB-45 (gp103) and MART-1 expression within giant cells in an atypical fibroxanthoma: a case report

BACKGROUND: Atypical fibroxanthoma (AFX) is a cutaneous tumor that primarily occurs in the sun-damaged skin of the head and neck of adults. It is often a rapidly growing, solitary lesion that may clinically resemble squamous cell carcinoma, malignant melanoma, or lobular hemangioma. The histologic differential diagnosis primarily includes spindle cell squamous carcinoma and spindle cell melanoma, and immunohistochemical studies are often needed to establish the diagnosis. CASE REPORT: We report an unusual case of an AFX with aberrant HMB-45 and MART-1 (melanoma antigen recognized by T cells-1) immunohistochemical expression. Clinical information was obtained. Histologic examination and immunohistochemical studies were performed. RESULTS: A 54-year-old woman presented with a 1.5 cm posterior scalp lesion, which was excised. Microscopic examination revealed a dermal tumor composed of pleomorphic and spindled cells with numerous giant cells. The tumor cells expressed CD68 but did not express either keratin or S-100. In addition, there was focal gp100 (with HMB-45) and MART-1 expression limited to the large, multinucleated cells with vacuolated cytoplasm. A diagnosis of AFX was subsequently made. CONCLUSIONS: This is the first reported case of an AFX with HMB-45 and MART-1 reactivity.     

甲下无色素性黑素瘤远端淋巴结转移

报告1例甲下无色素性黑素瘤远端淋巴结转移.患者女,28岁.左拇指甲下淡红色肿物1年半.结合病史、皮损特点、实验室检查、皮损及肿大淋巴结组织病理改变、免疫组化检查结果,确诊为该病.     

Coexistence of tumor of the follicular infundibulum with an unusual trichilemmal tumor

Tumor of the follicular infundibulum (TFI) is a rare epithelial tumor, and its histogenesis is still somewhat debatable. The diagnosis of TFI cannot currently be made before biopsy, and it is most often misdiagnosed as basal cell carcinoma (BCC). A 78-year-old woman presented to the dermatology clinic with a slightly erythematous nodule surrounded by fine telangiectasia on her right temple. Histopathologic examination of the lesion revealed an epithelial tumor with a plate-like growth pattern as is typical of TFI. In the same specimen, an unusual trichilemmal tumor with multiple epidermal connections was observed adjacent to the foci of TFI. The lobular tumor was composed of a large mass of keratinocytes with pale cytoplasm arranged as sheets and interconnecting ribbons. Several cells with hyperchromatic nuclei and small foci of compact cornification were also noted within the bulk of the tumor. The histopathologic features of the unusual tumor were reminiscent of BCC with trichilemmal differentiation or desmoplastic trichilemmoma.     

Trichoepithelioma with giant and multinucleated neoplastic epithelial cells

We report an unusual example of trichoepithelioma containing giant and multinucleated cells in the epithelial compartment. The patient was a 52-year-old woman who presented with a solitary nodule on the scalp measuring 2 cm of apparently long duration. The biopsy revealed a typical trichoepithelioma. The unusual feature was the presence in some epithelial nodules of large epithelial cells with hyperchromatic nuclei and no visible nucleoli that exceed 3 to 5 times the adjacent follicular germinative cells. Often, multinucleated cells were seen. Rare nodules were almost entirely composed of giant/multinucleated cells. The majority of the nodules containing giant cells were situated in the deeper portion of the neoplasm. No mitoses were seen in these giant cells. No enlarged or multinucleated cells were seen in the stroma. The neoplastic epithelial cells were diffusely reactive for bcl-2, including the giant and multinucleated cells. The proliferating rate was low; Ki-67 stained some giant cells. CD34 stained the stroma. We believe that the focal presence of pleomorphic giant cells in trichoepithelioma has no clinical or prognostic implications and does not denote its "malignant transformation".     

Subungual chondroblastoma in a 9-year-old girl

Chondroblastoma is an uncommon primary bone tumor, mainly found in the epiphyses of long bones. We describe a 9-year-old girl who presented with a chondroblastoma as a subungual mass in the fifth toe. Radiographs showed an expansive, calcified tumor of the distal phalanx. Histologic examination after excision revealed chondroid differentiation, active mitosis, multinucleated giant cells, calcification, and necrosis. There was no recurrence of the lesion after surgical excision. The purpose of this report is to document this unusual event that occurred in such a short bone as the distal phalanx of the fifth toe, mimicking a dermatologic entity.     

Myxoinflammatory fibroblastic sarcoma of the face

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare low-grade tumor of modified fibroblasts, with tendency to local recurrence. This unusual entity typically presents as a slow-growing painless mass in the distal extremities of middle-aged subjects. A 48-year-old woman presented to our clinic with a painless subcutaneous mass in the right temporal region. Excisional biopsy made the rare diagnosis of MIFS. Histologic examination showed the unique features that characterize this lesion: a myxoid component with a superimposed inflammatory infiltrate and the presence of distinctive, large, and bizarre Reed-Stemberg-like cells. A second wide tumor bed resection was performed, achieving clear margins. No adjuvant therapy was administered, and the patient is free of disease at 18 months postoperatively. To the best of our knowledge, this is the first reported case of MIFS presenting in the face. This adds another possibility for differential diagnoses of soft tissue tumors of the face.     

Acinic cell carcinoma on the lower lip resembling a mucocele

A 64-year-old woman presented with a 2-week history of an asymptomatic mass involving the lower lip. Histopathological examination showed a well-circumscribed tumour composed of many lobules separated by thin, fibrous connective tissue. Individual lobules were composed of round or polyhedral tumour cells, which had a characteristic finely granular and vacuolated cytoplasm and eccentric hyperchromatic nuclei. Positive staining was observed with Periodic acid-Shiff, and immunohistochemistry for cytokeratin, alpha-1 antitrypsin, and S-100 protein resulting in a final diagnosis of acinic cell carcinoma. Acinic cell carcinoma represents a well-established, although uncommon, entity in the classification of neoplasms of salivary gland origin. The parotid salivary gland is the most frequent site of acinic cell carcinoma, whereas the lip is a particularly unusual site. The unusual presentation of this tumour may lead to confusion with a mucocele. Given these findings, we suggest that acinic cell carcinoma should be considered in the differential diagnosis of any mucocele-like mass on the lower lip.     

Dermal pleomorphic liposarcoma resembling pleomorphic fibroma: report of a case and review of the literature

Pleomorphic liposarcoma (PLPS) is a rare, high‐grade sarcoma defined by the presence of pleomorphic lipoblasts. Constituting 5% of all liposarcomas, PLPS usually arises in deep soft tissues of the extremities, with rare occurrences in the dermis and subcutis. We describe a unique case of an 85‐year‐old Caucasian gentleman with a 1 year history of a pedunculated, pink, non‐tender papule on the dorsum of his left arm, measuring 1.0 cm in maximum dimension. Biopsy revealed a dermal collection of atypical epithelioid and spindle cells superimposed on a sclerotic background, resembling a pleomorphic fibroma on low power. On high power, a central focus of discrete adipocytic differentiation with pleomorphic lipoblasts was present. Tumor cells were positive for S‐100 and negative for desmin, actin, CD68, keratin, MART‐1 and CD34. Clinicopathologic findings were consistent with PLPS and the diagnosis was made. PLPS is rarely localized to the dermis and one with low power features resembling a pleomorphic fibroma has not been previously described in the literature.     

甲周纤维瘤继发甲脱落一例

患者,女,57岁.半年前无明显诱因右手中指甲右侧缘出现肿物,指甲逐渐开裂.肿物组织病理示:(右手中指肿物)损害中央伴有成纤维细胞和胶原纤维束,呈垂直走向;(右手中指双层甲)甲板平整,甲下大量角化物,表皮角化过度、灶性角化不全.诊断为甲周纤维瘤继发甲脱落.予以外科手术切除甲周疣状肿物及上层甲板.     

Atypical fibroxanthoma-like amelanotic malignant melanoma: A case report and literature review

Atypical fibroxanthoma (AFX)-like malignant melanoma is very rare. Here, we report a case of amelanotic AFX-like melanoma in a 72-year-old Taiwanese woman presenting with two separate, asymptomatic, enlarging erythematous nodules within a large hypopigmented patch on her left cheek. Histologically, both lesions showed cellular nodules in the reticular dermis separated from the overlying flattened epidermis by a zone of solar elastosis or fibrosis. The tumor consisted of sheets of atypical epithelioid cells arranged in a vague nesting pattern, as well as many atypical large or gigantic cells with one or more, large hyperchromatic, vesicular, or pleomorphic nuclei with prominent nucleoli, and moderate-to-abundant eosinophilic or foamy cytoplasm. Focal intraepidermal proliferation of atypical melanocytes with a pagetoid pattern was found only in the periphery of the main tumor. The tumor cells were moderately to strongly positive for S-100, Melan-A, and HMB-45. The pleomorphic giant cells were focally CD68-positive but CD163-negative. The patient underwent tumor excision followed by radiotherapy due to the narrow surgical margins. A sentinel lymph node biopsy revealed no metastasis of the melanoma. This case illustrates the importance of scrutinizing any subtle proliferation of atypical melanocytes in the epidermis in an AFX-like tumor in order to avoid misdiagnosis.     

Solitary sclerotic fibroma of the skin: morphological characterization of the 'plywood-like pattern'

Sclerotic fibroma is an uncommon skin tumor. Rapini and Golitz reported 11 cases of solitary sclerotic fibromas in patients without Cowden's disease in 1989. We report a case of sclerotic fibroma that presented as an asymptomatic nodule in a 34-year-old Japanese man. Histopathological examination revealed typical features of sclerotic fibroma of the skin. Ultrastructural examination showed that spindle cells with myoid features had proliferated around the vasculature. They had segregated from the perivascular area by leaving the surrounding basal lamina, resulting in their phenotypical change to produce collagen accumulating in a concentrically lamellar fashion. We suggest a possible role of abnormal blood vessels and surrounding specific cells in the development of sclerotic fibroma.     

Symplastisches Hämangiom

BACKGROUND AND OBJECTIVE: Endothelial nuclear atypia is the hallmark of malignant vascular tumors. Pleomorphic nuclei of the muscular vessel wall and the adventitia are manifestations of degenerative phenomena and should not be misinterpreted as signs of malignancy. PATIENTS/METHODS: Three long-standing solitary superficial vascular tumors (61-year-old woman, 48- and 63-year-old men) were removed by primary excision. Sections were stained according to standard histologic and immunohistologic protocols. RESULTS: Symplastic hemangiomas show the silhouette of a small superficial angioleiomyoma or capillary hemangioma. Characteristic features are multinucleate cells of the muscular vessel wall and the adventitia with pleomorphic nuclei, broad hyalinized vessel walls, and the distinctive lack of endothelial nuclear atypia. Recurrences or metastases were not reported (follow-up of 9, 45 and 90 months). CONCLUSIONS: Symplastic hemangioma is a benign superficial hemangioma with histological features of a pseudomalignancy. The distinctive lack of endothelial nuclear atypia allows distinction from malignant vascular tumors.     

Malignant hair matrix tumor ("malignant trichoepithelioma") arising in the setting of multiple hereditary trichoepithelioma

An unusual adnexal tumor on the scalp of a 59-year-old woman with hereditary trichoepithelioma is reported. After the initial removal, the tumor recurred twice during a 4-year period. Mohs micrographic surgery resulted in full excision of the lesion. Two years later there was no evidence of recurrence. Histologic examination of the tumor showed it to merge with adjacent areas of classic trichoepithelioma. The tumor showed cytologic atypia, mitotic figures, necrosis, deep infiltration, and features of pilar differentiation including clear cells, reminiscent of cells of the follicular outer root sheath, and focal shadow-cell formation. The differential diagnosis of this malignant follicular neoplasm included pilomatrix carcinoma and basal-cell carcinoma with matrical differentiation. The unique clinicopathologic features, however, raised consideration of a "malignant trichoepithelioma."     

Osteogenic Sarcoma Arising in an Old Burn Scar

An osteogenic sarcoma arising in an old burn scar on the right thigh of a 70-year-old woman is described. Salient features of this rare cutaneous tumor were: a large pinkish exophytic mass, spindle and oval cells, multiple foci of osteoid formation, atypical osteoblasts and multinucleated giant cells.     

Malignant granular cell tumor.

A malignant granular cell tumor (MGCT) appeared on the subungual tissue of the right index finger of a 51-year-old woman. Two years after resection of the tumor, it recurred, and the finger finally had to be amputated. Six months later, she noticed multiple cutaneous nodules on her trunk. Despite chemotherapy and X-ray irradiation, the patient died 18 months after the second operation. Histology of the specimen revealed a proliferation of both polygonal and spindle-shaped cells with large hyperchromatic nuclei and an eosinophilic granular cytoplasm. Peripheral nerves were encompassed by the tumor cells. Immunohistochemically, the tumor cells were positive for S-100 protein and Leu 7 (myelin-associated glycoprotein). These findings support the hypothesis that MGCT cells are of Schwann cell origin.