Metastasizing dermatofibroma

Perineural Invasion as a Clue to Malignant Behavior in a Dermatofibroma

Dermatofibroma (DF) represents one of the most common mesenchymal proliferations of the skin. Their recurrence rate, even when incompletely excised, is very low, whereas the atypical, aneurysmal, and cellular variants have recurrence rates of up to 20% each. Extraordinary rare malignant lesions with metastases to lymph nodes and/or lung have been described. We report a 64-year-old woman with a long history (years) of a skin lesion on her right arm that became painful during the last months. Histologically, it consisted of a conventional cellular DF in which perineural invasion was present. Subsequently, the lesion showed a clinically aggressive course with recurrences, sarcomatous transformation, and pulmonary metastases. Given that no predictive morphological features have been identified to separate classical benign DF from rare metastasizing forms, perineural invasion in an otherwise conventional DF could be a histopathologic clue for an adverse prognosis and should provoke a closer clinical follow-up.

Dermatofibroma—A Critical Evaluation

Dermatofibromas are common cutaneous lesions. In most cases, they can be readily identified clinically and show a typical histology. In a small percentage of cases they show unusual clinical and more often histologic features that may cause differential diagnostic problems. In addition there are reactive fibrous lesions with neural or smooth muscle features that we speculate may represent dermatofibroma variants.

Malignant dermatofibroma: clinicopathological, immunohistochemical, and molecular analysis of seven cases

Dermatofibroma (cutaneous fibrous histiocytoma) represents a common benign mesenchymal tumor, and numerous morphological variants have been described. Some variants of dermatofibroma are characterized by an increased risk of local recurrences, and there are a few reported metastasizing cases. Unfortunately, an aggressive behavior cannot be predicted reliably by morphology at the moment, and we evaluated the value of array-comparative genomic hybridization (CGH) in this setting. Seven cases of clinically aggressive dermatofibromas were identified, and pathological and molecular features were evaluated. The neoplasms occurred in four female and in three male patients (mean age was 33 years, range 2-65 years), and arose on the shoulder, buttock, temple, lateral neck, thigh, ankle, and cheek. The size of the neoplasms ranged from 1 to 9 cm (mean: 3 cm). An infiltration of the subcutis was seen in five cases. Two neoplasms were completely excised, whereas an incomplete or marginal excision was reported in the remaining cases. Local recurrences were seen in six cases (time to the first recurrence ranged from 8 months to 9 years). Metastases were noted between 3 months and 8 years after diagnosis in six patients. Two patients died of disease, and two patients are alive with disease. Histologically, the primary tumors showed features of cellular dermatofibroma (four cases), cellular/aneurysmal dermatofibroma (one case), atypical/cellular dermatofibroma (one case), and classical dermatofibroma (one case). Mitotic figures ranged from 3 to 25 per 10 high-power fields, and focal necrosis was present in five cases. Interestingly, malignant transformation from cellular dermatofibroma to an obvious spindle cell/pleomorphic sarcoma was seen in one primary and in one recurrent neoplasm. Five neoplasms showed chromosomal aberrations by array-CGH, suggesting that these changes may represent an additional diagnostic tool in the recognition of cases of dermatofibroma with a metastatic potential.

Cystic fibrohistiocytic tumor of the lung presenting as a solitary lesion

Cystic fibrohistiocytic tumor of the lung is a rare neoplasm. In many cases it represents a metastasis from a benign or low-grade fibrohistiocytic tumor of the skin, but occasionally it may be primary. Radiologically it usually occurs as a cystic change of multiple pulmonary nodules, and pneumothorax is the most frequent presenting symptom. We present here a 16-year-old man with recurrent right pneumothorax. The patient had no history of cutaneous fibrohistiocytic lesions. He underwent videothoracoscopic right apical segmentectomy, right lower lobe nodulectomy, and pleuroabrasion. Microscopy of the apical segmentectomy showed a cystic fibrohistiocytic tumor, whereas the nodule of the lower lobe was an intraparenchymal lymph node. The patient is alive with no tumor recurrence. The differential diagnosis includes Langerhans cell histiocytosis, lymphangioleiomyomatosis, pleuropulmonary blastoma, and metastatic endometrial stromal sarcoma. This disease usually occurs with multiple pulmonary cysts and cavitation. This case is the first reported presenting as a single lesion.

Cutaneous fibrohistiocytic tumours - an update

The term 'fibrohistiocytic' tumour is a descriptive designation without histogenetic connotation for a group of heterogeneous lesions that share morphological features of histiocytes and fibroblasts on light microscopy. However, over the years it has become apparent that many so-called 'fibrohistiocytic' tumours are largely composed of relatively undifferentiated mesenchymal cells, but can also show areas of myofibroblastic differentiation. This review focuses on the clinical and histological features as well as differential diagnosis of so-called fibrohistiocytic tumours. Special emphasis is given to more recently described histological variants of fibrous histiocytoma, e.g. cellular, epithelioid, aneurysmal and atypical fibrous histiocytoma, to angiomatous and plexiform fibrous histocytoma (plexiform fibrohistiocytic tumour), lesions that are not true variants of fibrous histiocytomas but have erroneously been designated such, and to atypical fibroxanthoma. The literature on metastasizing fibrous histiocytoma is also reviewed.

Deep "benign" fibrous histiocytoma: clinicopathologic analysis of 69 cases of a rare tumor indicating occasional metastatic potential

Benign fibrous histiocytoma (FH) is one of the most common mesenchymal neoplasms of the skin. Several histologic variants of cutaneous FH have been described, some of which also have distinct clinical features including a propensity for local recurrence. Deep benign FH is an uncommon and poorly recognized clinical subtype that arises in subcutaneous or deep soft tissue. Only a single small series of these neoplasms has been published, and their clinical behavior is not well characterized. In this study, we report the clinicopathologic features of 69 deep FH retrieved from our consultation files. The patients included 41 males and 28 females, ranging in age from 6 to 84 years (median, 37 y). The most common anatomic location was the extremities (58%); the remainder arose on the head and neck (22%), trunk (11%), and in the deep soft tissue of the retroperitoneum, mediastinum, or pelvis (9%). All lesions arising in nonvisceral soft tissue were subcutaneous. The tumors ranged from 0.5 to 25 cm in size (median, 3.0 cm) and were well circumscribed grossly and microscopically. All tumors were composed of bland ovoid to spindle cells arranged in a storiform pattern with admixed lymphocytes. Multinucleate giant cells, osteoclastic giant cells, and/or foam cells were present in 59% of cases, whereas the other 41% were cytologically monomorphic, often resembling cellular FH. Other common findings included a hemangiopericytomalike vascular pattern (42%) and stromal hyalinization (39%). Four cases were classified as atypical deep FH due to the presence of scattered markedly pleomorphic spindle cells within an otherwise histologically typical lesion. The median mitotic rate was 3/10 HPF; 10 cases (14%) had >10 mitoses/10 HPF. Necrosis (2 cases) and lymphovascular invasion (1 case) were rare. Immunohistochemistry revealed expression of CD34 in 20/50 cases (40%), smooth muscle actin in 15/40 (38%), and focal desmin in 1/12 (8%). Of the 37 patients for whom clinical follow-up was available (median, 40 mo), 8 (22%) had a local recurrence; in all 8 cases, the tumor had been marginally or incompletely excised. Metastases occurred in 2 patients (5%), both of whom ultimately died of disease; however, this number is likely exaggerated due to consultation bias. The metastasizing tumors were large (6 and 9 cm) and 1 had tumor necrosis but they were otherwise histologically identical to the nonmetastasizing lesions. In summary, deep FH has many histologic features in common with cutaneous cellular FH; however, it usually has a more diffusely storiform pattern than the latter, is well circumscribed, and may have striking hemangiopericytomalike vessels. Similar to the cellular, aneurysmal, and atypical variants of FH, deep FH recurs in approximately 20% of cases and may rarely metastasize.

“Benign” metastatic meningioma: clinico-pathological analysis of one case metastasising to the lung and overview on the concepts of either primitive or metastatic meningiomas of the lung

Lung "metastases" of benign meningiomas are rarely described events of biological and clinical interest. We, here, report of a 70-year-old healthy woman found by CT scan to have multiple lesions, the two largest in the right lung on routine examination. Anamnesis revealed that the patient underwent a surgical resection of cerebral meningioma 12 years before. The larger lung lesion was a 3-cm node located in the right lung and was removed by wedge resection. Macroscopically, it showed well-defined borders, whitish colour and firm consistency; histologically, it was uniformly composed by spindle meningothelial cells arranged in fascicules including psammoma bodies. The morphological and immunohistochemical features of this lesion, together with the similarity with the original cerebral tumour and its indolent evolution, led to a final diagnosis of "benign" meningioma metastatic to the lung. Lung metastatic meningiomas may be a diagnostic challenge because of their unusual site of presentation and the possible confusion with primitive lung meningiomas or primary mesenchymal lung lesions. They represent a typical example of "benign" tumours that may implant to the lung similar to other tumours, definitely considered benign but reported to rarely present unusual secondary localization.

Metastasizing dermatofibroma in lung

Benign dermatofibroma is very common skin tumor and can very rarely metastasize. We report a case of metastasizing dermatofibroma on a 36-year-old woman who presented multiple bilateral lung nodules. She underwent incisional biopsy for cellular dermatofibroma of the right shoulder 7 years ago. Chest computed tomographic scanning shows multiple nodules in both lung fields. Segmental and wedge resections were done. Grossly, the masses were hemorrhagic cysts. Microscopically, there were dilated cystic airspaces. The airspaces were lined by respiratory and metaplastic squamous epithelium with underlying layers of fibrohistiocytic spindle cells with storiform and fascicular pattern. The tumor cells stained for CD68 and CD10. The lung mass shows same histologic features with skin lesion.

Imaging of macrophage-related lung diseases

Macrophage-related pulmonary diseases are a heterogeneous group of disorders characterized by macrophage accumulation, activation or dysfunction. These conditions include smoking-related interstitial lung diseases, metabolic disorders such as Niemann-Pick or Gaucher disease, and rare primary lung tumors. High-resolution computed tomography abnormalities include pulmonary ground-glass opacification secondary to infiltration by macrophages, centrilobular nodules or interlobular septal thickening reflecting peribronchiolar or septal macrophage accumulation, respectively, emphysema caused by macrophage dysfunction, and honeycombing following macrophage-related lung matrix remodeling.

Cystic fibrohistiocytic tumours presenting in the lung: primary or metastatic disease?

AIMS

Cystic fibrohistiocytic tumour of the lung is a rare proliferative process. Its histogenesis is uncertain, but evidence suggests that some cases represent metastatic disease from apparently indolent skin lesions, namely cellular fibrous histiocytomas. This study presents four cases and reviews the literature concerning this pattern of disease and its aetiology.

METHODS AND RESULTS

All patients were male (age range 35-54 years). Two presented with recurrent haemoptysis. Two cases had histories of cutaneous fibrohistiocytic lesions in the chest wall, excised 10 and 23 years prior to presentation with lung disease. Imaging data showed multiple bilateral cystic lung lesions in all four patients with nodular cavitating opacities seen on high-resolution computed tomography scans. Microscopy showed variably dilated thin-walled cystic airspaces lined by cuboidal epithelium and an underlying layer of mildly pleomorphic spindle cells with slightly wavy morphology and storiform architecture, admixed with inflammatory cells. Tumour cells stained for CD68 in three of four cases. All cases were negative for CD34. All patients were alive with disease, although one required pneumonectomy for intractable haemoptysis.

CONCLUSION

This study and a review of published cases show that the majority of cystic fibrohistiocytic tumours of the lung probably represent metastases from cellular fibrous histiocytomas. However, rare cases may be either primary in origin or the primary site remains occult; the term cystic fibrohistiocytic tumour remains appropriate for such cases.

Atypical fibrous histiocytoma of the skin: clinicopathologic analysis of 59 cases with evidence of infrequent metastasis

Atypical fibrous histiocytoma is an uncommon, poorly documented variant of cutaneous fibrous histiocytoma. We studied 59 cases of atypical fibrous histiocytoma to better characterize the clinicopathologic spectrum. There were 33 males and 26 females (median age 38 years; range 5-79 years) with solitary lesions arising on lower (25 cases) and upper (17 cases) extremities, trunk (6 cases), head and neck (4 cases), and vulva (1 case); anatomic location was not stated in six cases. Lesions measured 0.4-8 cm in diameter (median 1.5 cm) and clinically were nodules (40 cases), polypoid tumors (18 cases), or a slightly elevated plaque (1 case). Histologically, the lesions were primarily dermal with superficial involvement of the subcutis in one third of the cases. Salient features included a proliferation of pleomorphic, plump, spindle, and/or polyhedral cells with mainly large, hyperchromatic, irregular, or bizarre nuclei, set in a background of classic features of fibrous histiocytoma, including spindle cell areas showing a storiform pattern and entrapped thickened, hyaline collagen bundles, especially at the periphery. Multinucleated giant cells, often with bizarre nuclei and foamy, sometimes hemosiderin-rich, cytoplasm were also variably present. The degree of pleomorphism varied from only focal and minimal (14 cases) or moderate (24 cases) to marked (21 cases). Mitotic activity was observed in 55 lesions, and the number of mitotic figures ranged from 1 to 15 per 10 high power fields. Atypical mitoses were noted in 20 lesions. Furthermore, some cases of atypical fibrous histiocytoma displayed other worrisome features less often observed in ordinary FH, including unusually large size (diameter >2 cm, 8 cases), involvement of the superficial subcutis (19 cases), and geographic necrosis (7 cases). Immunohistochemical studies performed in 42 cases showed only focal smooth muscle actin (10 cases) and CD34 (4 cases) positivity, whereas CD68, S-100 protein, desmin, pan-keratin, and epithelial membrane antigen were negative. Clinical follow-up data available in 21 patients (mean duration of follow-up 50.6 months, median 43 months) revealed local recurrences in three patients (one repeated); two patients developed distant metastases, one of whom died after 96 months. These two cases were not histologically distinct from the group as a whole. We conclude that atypical fibrous histiocytoma has a broader clinicopathologic spectrum than previously realized. Lesions with floridly atypical features represent potential pitfalls for overinterpretation as pleomorphic sarcoma, which would appear to be inappropriate in most cases. Provided that atypical fibrous histiocytoma is treated by complete excision, a benign outcome is to be expected in most cases. However, similar to the cellular and aneurysmal variants of fibrous histiocytoma, atypical fibrous histiocytoma shows a higher tendency to recur locally than ordinary fibrous histiocytoma and may rarely metastasize.

Metastasizing fibrous histiocytoma of the skin: a clinicopathologic and immunohistochemical analysis of three cases

The clinicopathologic and immunohistochemical features of three metastasizing fibrous histiocytomas of the skin are presented. The first patient had a 1.3-cm nodule in the right thigh, with right inguinal lymph node metastases 19 years later. The second patient, who had a 3-cm nodule excised from his left thigh and inguinal lymph node metastasis after 4 months, had a favorable outcome 14 years after local radiotherapy and chemotherapy. The third had a 2-cm nodule in his neck, which recurred 16 months later. Four months later, cervical lymph node metastases were found. The patient was alive and well 26 months after initial surgery. All three primary skin tumors involved the dermis and subcutis, appeared well-delineated but nonencapsulated, were associated with some degree of epidermal hyperplasia, and showed features of aneurysmal/atypical or cellular fibrous histiocytoma. The number of mitoses ranged from 6 to 11 per 10 high-power fields. Recurrences and metastases showed morphologic features similar to primary lesions. Tumor cells were positive, at least focally, for CD 68, Ki-M1p, and Factor XIIIa, and occasionally for smooth muscle actin. Desmin, CD 34, S-100 protein, and cytokeratin stainings were negative. Primary neoplasms, recurrences, and metastases showed a Mib-1 labeling index of 10% or less. Cellular, aneurysmal, and atypical (pseudosarcomatous) fibrous histiocytomas of the skin can metastasize, yet they often show a protracted clinical course. Risk factors for metastatic dissemination include large size, high cellularity, aneurysmal changes, marked cellular pleomorphism, high mitotic activity, tumor necrosis, and repeated local recurrences.