Granular cell atypical fibroxanthoma: report of two cases

Two cases of an uncommon histopathological variant of atypical fibroxanthoma (AFX) are described. Even though both lesions presented as clinically conventional atypical fibroxanthoma, histopathology disclosed a neoplasm composed of cells with granular change that was negative for S100 staining, and showed prominent pleomorphism, severe nuclear atypia, and a high mitotic index. Degenerative change may explain the granular phenotype in these two cases of AFX. The differential diagnosis with primitive nonneural granular cell tumor is discussed.     

Clear-cell atypical fibroxanthoma: an uncommon histopathologic variant of atypical fibroxanthoma

Atypical fibroxanthoma is a superficial variant of pleomorphic malignant fibrous histiocytoma. Histopathologically, it is characterized by a dermal nodule composed of bizarre cells arranged in a haphazard-to-fascicular pattern. These cells are spindle or rounded, pleomorphic and with numerous atypical mitotic figures. Some cells appear polygonal with ample and foamy cytoplasm. We recently encountered two elderly patients with atypical fibroxanthoma on their face. Histopathologically, one of the lesions was composed, almost entirely, of clear cells, whereas in the other one aggregations of clear cells constituted a half of the neoplasm. Atypical multinucleated cells with a Touton-like appearance were present. In addition to clear cells, areas of more conventional atypical spindle cells arranged in fascicles were seen, supporting the diagnosis of atypical fibroxanthoma. PAS staining failed to demonstrate glycogen in neoplastic cells. Immunohistochemistry revealed that neoplastic cells expressed positivity for vimentin, muscle-specific actin, and alpha smooth muscle actin, whereas cytokeratin, S-100 protein, EMA, CEA, and clesmin were negative. Ultrastructural studies showed that neoplastic cells contained abundant rough endoplasmic reticulum, mitochondria, and numerous lipid vacuoles within the cytoplasm. Clear-cell atypical fibroxanthoma is a rare variant of atypical fibroxanthoma that should be differentiated from other clear-cell neoplasms of the skin.     

The atypical fibroxanthoma

A 84-year-old female patient suffering from atypical fibroxanthoma is presented. A diagnosis of malignant melanoma or a cutaneous metastasis from an unknown primary tumor was suspected. The final diagnosis was established by immunohistological studies showing a strongly positive reaction to vimentin and a negative reaction to S-100 protein and cytokeratin.     

Granular cell atypical fibroxanthoma

We report on two patients with granular cell atypical fibroxanthoma. Both neoplasms were solitary, light-tan, dome-shaped papules on sun-exposed areas of the head in two elderly white men. Microscopically, these neoplasms showed a dermal proliferation of pleomorphic granular cells with irregular hyperchromatic nuclei, multinucleated cells, and scattered mitoses. Immunohistochemical stains were positive for CD68 and vimentin and negative for Melan-A or human melanoma black (HMB)-45, S-100 protein, pancytokeratin, and actin, consistent with atypical fibroxanthoma. The differential diagnosis of granular cells in neoplasms containing cytological pleomorphism is challenging in view of the many different neoplasms that may present with granular cytoplasm. These include the conventional granular cell tumor and its malignant form, leiomyoma, leiomyosarcoma, dermatofibroma, dermatofibrosarcoma protuberans, and angiosarcoma.     

Melanoma simulating atypical fibroxanthoma

Melanoma may present with a wide variety of clinicopathological presentations, among those very rarely lesions imitating atypical fibroxanthoma (AFX). While AFX usually is cured by complete excision, melanoma simulating AFX has a much more serious prognosis, and thus is important to be recognized correctly. The present series describes 4 cases of such melanomas in 3 patients whose exact diagnosis was (markedly) delayed due to unusual clinicopathological presentations including negative immunohistochemistry for melanocytic markers (S100 protein, MelanA/MART1, HMB45).     

皮肤非典型性纤维黄色瘤

自Helwig(1963)首先命名本病以来,近年来已引起国内外的高度重视(1-8).本病形态上具有高度恶性的组织象,但其临床生物学行为往往为良性.少数病例术后易复发,转移病例甚少(4-6)鉴于本病国内报道很少,兹将我院所见3例报告于下.     

非典型纤维黄瘤一例

患者男,44岁,发现右食指包块6个月。约6个月前发现右食指米粒大小结节,伴轻微疼痛,未治疗。以后肿块逐渐增大,疼痛加剧,轻微瘙痒,有时渗出淡血性液体……     

Keloidal atypical fibroxanthoma: a case series

Background:  Keloidal atypical fibroxanthoma (AFX) is a rare variant of AFX with thick bands of hyalinized collagen. The identification of keloidal collagen associated with fibrohistiocytic cells may erroneously lead to the diagnosis of keloidal dermatofibroma. Although AFX is a pleomorphic cutaneous tumor typically associated with a good prognosis, occasional reports of metastatic AFX highlight the importance of accurate identification.
Methods:  A total of nine cases of an unusual variant of AFX with keloidal tumoral sclerosis were collected and examined. The cases were stained with antibodies directed against S100, cytokeratin, CD68 and CD31.
Results:  Histopathological examination revealed pleomorphic cells trapped within hyalinized keloidal collagen bands. In several cases, the keloidal collagen also formed ring-shaped structures surrounding CD31-positive vascular structures. Pleomorphic cells were negative for S100 protein and keratin, but consistently labeled with antibodies directed against CD68.
Conclusions:  The diagnosis of keloidal AFX requires the exclusion of other malignant and benign lesions with keloidal or sclerotic collagen. Awareness of the rare variant of keloidal AFX may avoid a diagnostic pitfall leading to an erroneous diagnosis, particularly in small biopsies. The finding of sclerotic collagen preferentially deposited around vessels is an interesting and poorly understood phenomenon.     

Myxoid atypical fibroxanthoma: a previously undescribed variant

Background: Atypical fibroxanthomas (AFX) are dermal-based cutaneous tumors typically found in sun-damaged skin of the elderly. Histologic variants include spindle cell, clear cell, osteoid, osteoclastic, chondroid, pigmented, and granular cell. To date, myxoid change in AFX, has not been described.
Methods: Four cases were retrieved from the consultation and surgical pathology files of Knoxville Dermatopathology Laboratory, Knoxville, Tennessee during a 4-year period. The clinical and histologic findings were reviewed and Alcian blue/periodic acid-Schiff (PAS) stain and panel of immunohistochemical stains was obtained.
Results: All 4 lesions occurred as solitary lesions in elderly males on the head and neck (2 cases) and upper extremity (2 cases). Histologically all tumors demonstrated a well-circumscribed, cellular lesion centered in the dermis and composed of a mix of atypical pleomorphic and spindle cells in a prominent myxomatous background. A junctional component was absent and the tumors did not arise from the epidermis or adnexal structures. Subcutaneous involvement was absent in all cases. Tumor cells were negative for melanocytic and epithelial markers. Positive staining was noted with CD10 (3/4 cases) and vimentin (4/4 cases).
Conclusion: Myxoid change in AFX is rare and previously undescribed in the English literature. Myxoid change may be a prominent finding in benign and malignant cutaneous tumors and awareness of this variant of AFX will avoid misdiagnosis.     

Aneuploidy in atypical fibroxanthoma: DNA content quantification of 10 cases by image analysis

It has recently been reported that atypical fibroxanthoma (AFX) is a predominantly diploid lesion in contrast to malignant fibrous hystiocytoma (MFH) which is usually aneuploid. To test this hypothesis, DNA content quantification was undertaken on Feulgen-stained cytology and tissue section preparations from 10 cases of AFX by image analysis. The large-atypical cells which characterize AFX were aneuploid in each case. Smaller spindle-shaped cells found in this lesion were diploid. The results suggest that AFX is indistinguishable from MFH by DNA content estimation and highlight an advantage of image analysis over (low cytometry.     

Clear cell atypical fibroxanthoma:a clinicopathologic study

INTRODUCTION: The atypical fibroxanthoma (AFX) is considered by most authorities to represent a superficial or minimally invasive variant of malignant fibrous histiocytoma that most often presents as a solitary nodule on the sun-exposed skin of the elderly. Among the rarest variants is the clear cell AFX, a lesion which raises consideration to a differential diagnosis encompassing a variety of neoplastic and non-neoplastic clear cell proliferations. METHODS: We describe three cases of a distinctive cutaneous neoplasm arising in the sun-exposed skin of elderly patients. In all cases, formalin-fixed, paraffin-embedded tissue was available for analysis. The histology in concert with the immunophenotype was held to be diagnostic of the clear cell variant of AFX. RESULTS: All tumors comprised sheets of large cells with foamy cytoplasms and hyperchromatic, polyploid nuclei manifesting frequent and atypical mitoses. The critical cells in our cases expressed CD68 but none of CD3, CD20, CD34, S-100 protein, muscle-specific actin, factor XIIIa, Melan-A, carcinoembryonic antigen, or cytokeratin. CONCLUSION: Although typical examples of AFX provoke diagnostic consideration of spindle cell cancers of the skin (most often spindle cell melanoma, spindle cell squamous cell carcinoma, and leiomyosarcoma), the clear cell variant raises other differential diagnostic considerations instead. These include balloon cell melanoma, sebaceous carcinoma, pleomorphic liposarcoma, chordoma, parachordoma, tricholemmal carcinoma and clear cell squamous cell carcinoma. A diagnosis of AFX is one of exclusion; one must employ immunohistochemical markers to rule out the aforementioned differential diagnostic considerations. By reporting the fifth, sixth and seventh cases of clear cell AFX, we hope to alert dermatopathologists to this distinctive and unusual neoplasm, recognition of which is essential to avoid under- or over-diagnosis and inappropriate therapy.     

Adult-onset Still''s disease with atypical cutaneous features

INTRODUCTION: The diagnosis of adult-onset Still's disease (AOSD) can be very difficult. There are no specific tests and reliance is usually placed on a symptom complex and the well described typical rash seen in most patients. In recent years, however, other cutaneous manifestations of AOSD have been reported but these are not so well known. OBSERVATIONS: We report a patient with urticaria and fixed plaques and review the other 'atypical' cutaneous findings associated with AOSD. CONCLUSIONS: The diagnosis of AOSD can be made in the absence of the typical Still's rash but in the presence of other atypical cutaneous features.     

An unusual presentation of atypical fibroxanthoma

Atypical fibroxanthoma (AFX) is a rare cutaneous spindle-cell neoplasm. The tumor occurs most commonly in sun-damaged skin of the head and neck in elderly patients. A small subset of patients (approximately one in five cases) is middle-aged and presents with AFX of the trunk or extremities in areas without evidence of actinic damage. We report an unusual case of AFX of the lower leg in an 81-year-old woman with extensive actinic damage.     

Recurrent atypical fibroxanthoma with satellite metastasis

Atypical fibroxanthoma (AFX) is a cutaneous neoplasm of uncertain etiology that develops on sun‐exposed regions of elderly males. It is widely considered to act indolently, despite its highly malignant cytologic features. Reports of metastatic AFX are very rare, and recurrence is uncommon. We report a case of recurrent AFX exhibiting a pattern of satellite metastasis followed by evidence of regional lymph node metastasis. A 76‐year‐old male with prior occupational and therapeutic radiation exposure and numerous squamous cell carcinomas had AFX of the left vertex scalp limited to the dermis completely removed by micrographic surgery. Twenty months later, multiple lesions appeared at the site of previous surgery. Imaging revealed no metastases or calvarial involvement. Wide local excision showed multiple well‐defined nodules involving dermis and subcutis. The primary and recurrent neoplasms were similar and composed of pleomorphic epithelioid and spindled cells with marked nuclear atypia, hyperchromasia and mitotic activity. Immunohistochemistry was positive for CD10, procollagen1 and vimentin and negative for cytokeratins AE1/AE3, cytokeratins 5/6, 34βE12, MNF116, p63 CD31, Mart1, smooth muscle actin, desmin, S100 and CD34. Forty‐eight months after removal of the primary, left intraparotid and posterior triangle lymph nodes are suspected to be involved by metastasis using clinical and positron emission tomography/ computed tomography examinations.     

CD117 immunoreactivity in atypical fibroxanthoma

Atypical fibroxanthoma (AFX) is a spindle cell neoplasm of the skin seen typically on sun-damaged skin of the elderly. Though described as a benign entity, local recurrence and distant metastasis have been reported. This study aims to investigate the potential pathogenic role of CD117, the c-kit receptor in AFX. CD117 was detected in 15 of the 16 cases (94%). The percentage of positive cells for CD117 expression among all tumors was approximately 30%. CD117 proved to be a very sensitive marker of AFX. This antibody may be a useful diagnostic adjunct in AFX.     

Dermatoscopic features of extrafacial lentigo maligna

The dermatoscopic features of classic lentigo maligna (LM) are well described; however, there is little literature available on extrafacial LM, which is a less frequently reported condition. The skin architecture is especially rich in adnexae on sun‐exposed areas such as the face, relative to other parts of the body, thus it is possible that the dermatoscopic findings of extrafacial LM will differ from the usual findings of LM. We carried out a dermatoscopic study on three patients with extrafacial LM. The dermatoscopic patterns reflected the underlying histological features of the disease, with increased melanocytes seen along the rete ridges and around follicular ostia, which result in a unique pigment network architecture.