Primary osteosarcoma of the skin

Primary cutaneous extraskeletal osteosarcoma: a series of 16 cases

Extraskeletal osteosarcoma (EOS) is a high grade soft tissue tumour characterised by the production of malignant osteoid, without attachment/involvement of underlying bone/periosteum. Rarely, EOS presents as a cutaneous tumour. The clinical behaviour of primary cutaneous EOS (PC-EOS) remains incompletely characterised. Herein we present the largest case series of PC-EOS reported to date. Sixteen PC-EOS cases from the archives/consultation files were retrieved (male:female 1:1; age 31-96 years, mean age 66 years). The tumours measured 1-10 cm (mean 3.2 cm) and were located on the lower extremity (7), head (6), upper extremity (2), and trunk (1). They consisted of pleomorphic, spindled-to-epithelioid cells, with fascicular, nodular, or sheet-like growth patterns and foci of malignant osteoid. Immunohistochemistry did not reveal specific lines of differentiation, and there was no evidence of other tumour types. A literature review was conducted to identify all well characterised cases of PC-EOS. A combined analysis of present and past cases was performed to determine overall trends in clinical characteristics and outcomes. The mean follow-up period was 23.9 months, during which 67.5% of patients experienced progression-free survival and 18% of patients died of disease. Rates of local recurrence and metastasis were 10% and 25%, respectively, approximately double past estimates. These data suggest that the prognosis of PC-EOS is less favourable than previously thought. The differential diagnosis includes benign entities (e.g., ossifying pyogenic granuloma) and malignant neoplasms with heterologous osteosarcomatous differentiation (e.g., carcinosarcoma, transdifferentiated melanoma). Wide excision remains the standard of care, and the role of chemotherapy and radiation remains inconclusive. Recognition of this rare entity can facilitate prompt diagnosis and appropriate treatment.

Cutaneous Fibrous Histiocytomas, Ossifying-Variant with Osteoclast-like Giant Cells and Granular Cell-Variant: A Series of Two Unusual Cases with Emphasis on the Differential Diagnosis

The ossifying variant and the granular cell variant are rare subtypes of cutaneous fibrous histiocytoma (CFH), characterized by islands of mature metaplastic bone tissue rimmed by multinucleated osteoclast-like giant cells and by large-sized cells with granular cytoplasm and mildly hyperchromatic nuclei with inconspicuous nucleoli, respectively. We herein present two cases of these unusual CFH variants in a 37-year-old woman and in a 38-year-old man, respectively. The main differential diagnoses, including both benign and malignant lesions, are also discussed.

Cutaneous osteosarcoma arising from a burn scar

Tumors that develop in old burn scars are usually squamous cell carcinomas. Sarcomas have also been reported, albeit rarely. To our knowledge, there has been only one case report of an extraskeletal osteosarcoma arising in a prior burn scar reported in the English-language literature, mainly discussing the clinicopathological features. Herein, we present a case of cutaneous osteosarcoma visualized as a mineralized soft-tissue mass arising from the scar associated with a previous skin burn over the back. This seems to be the first report describing the imaging features of a cutaneous osteosarcoma from an old burn scar.

Cutaneous metastases from internal malignancies: a clinicopathologic and immunohistochemical review

Skin metastases occur in 0.6%-10.4% of all patients with cancer and represent 2% of all skin tumors. Skin metastases from visceral malignancies are important for dermatologists and dermatopathologists because of their variable clinical appearance and presentation, frequent delay and failure in their diagnosis, relative proportion of different internal malignancies metastasizing to the skin, and impact on morbidity, prognosis, and treatment. Another factor to take into account is that cutaneous metastasis may be the first sign of clinically silent visceral cancer. The relative frequencies of metastatic skin disease tend to correlate with the frequency of the different types of primary cancer in each sex. Thus, women with skin metastases have the following distribution in decreasing order of frequency of primary malignancies: breast, ovary, oral cavity, lung, and large intestine. In men, the distribution is as follows: lung, large intestine, oral cavity, kidney, breast, esophagus, pancreas, stomach, and liver. A wide morphologic spectrum of clinical appearances has been described in cutaneous metastases. This variable clinical morphology included nodules, papules, plaques, tumors, and ulcers. From a histopathologic point of view, there are 4 main morphologic patterns of cutaneous metastases involving the dermis, namely, nodular, infiltrative, diffuse, and intravascular. Generally, cutaneous metastases herald a poor prognosis. The average survival time of patients with skin metastases is a few months. In this article, we review the clinicopathologic and immunohistochemical characteristics of cutaneous metastases from internal malignancies, classify the most common cutaneous metastases, and identify studies that may assist in diagnosing the origin of a cutaneous metastasis.

Osteosarcoma of the skin

BACKGROUND

Osteosarcoma is a common malignancy, although skin metastasis is rare. We sought to review the incidence, epidemiology, risk factors, and prognosis of osteosarcoma with skin involvement.

METHODS

We conducted a retrospective chart review that covered 30 years and involved clinic patients younger than 18 years who had cutaneous metastases of osteosarcoma. The main outcome measure was histologic documentation of both primary tumor and metastatic lesion in the skin.

RESULTS

Two patients were found to have osteosarcoma with skin involvement. No unifying factors were identified.

CONCLUSIONS

Although osteosarcoma is a common malignancy with frequent metastases, involvement of the skin is rare. Further studies to identify risk factors and subsequent prognosis are necessary. Nevertheless, unidentifiable skin lesions in a patient with a history of osteosarcoma should be investigated to rule out tumor metastasis, regardless of cancer status.

Cutaneous metastasis of extraskeletal osteosarcoma arising in the mediastinum

Cutaneous metastases have been reported in 5%-10% of patients with internal malignancy. The most common clinical features are the sudden appearance of discrete, firm, and nontender nodules in a particular area of the body. The most frequent metastatic site of extraskeletal osteosarcoma (ESOS) is the lungs. Cutaneous metastasis of ESOS is rare. To our knowledge, only one case of ESOS has been reported with skin metastasis, histopathologically classified as the osteoblastic subtype. Here, we describe a case of chondroblastic ESOS arising in the mediastinum with metastasis to the skin. Our patient presented with a scalp nodule after diagnosis of primary ESOS at the mediastinum.

[Metastatic extraskeletal osteosarcoma revealed by an occipital mass]

BACKGROUND

Extraskeletal osteosarcoma is a rare mesenchymatous tumour occurring in adults aged over 50 years and is located mainly in the limbs or retroperitoneum. We report a case of metastatic extraskeletal osteosarcoma revealed by a cutaneous occipital tumour site.

CASE-REPORT

A 53-year-old woman was admitted for dyspnea and weight loss. An occipital tumour, noticed for one year by the patient, was discovered. It was freely movable on the bone, of hard consistency and responsible for alopecia. In addition to left-sided pleural effusion, a chest CAT revealed a large mass in the left lung, including areas of necrosis and calcifications with intracardiac extension. Histological examination of biopsies of the skin and of pulmonary and intracardiac lumps showed an osteosarcomatous proliferation. No primary osteosarcoma was found in the bones. A diagnosis was made of metastatic extraskeletal osteosarcoma. Intravenous chemotherapy was given followed by radiotherapy. After a six-month stabilization period, the disease progressed.

DISCUSSION

Extraskeletal cutaneous locations of osteosarcoma are extremely rare. They may comprise either the primary tumour or a metastatic lesion. In this patient, the immediately metastatic nature of the disease was a poor prognostic factor for this high-grade sarcoma.

Sarcomatoid Basal Cell Carcinoma—Predilection for Osteosarcomatous Differentiation

Primary cutaneous carcinomas rarely show heterologous malignant mesenchymal differentiation. We report 11 cases of sarcomatoid basal cell carcinoma (BCC) with osteosarcomatous differentiation. The patients (7 men and 4 women) ranged in age from 61 to 92 years (median 75 y). The tumors presented as exophytic nodules (0.3 to 7 cm) on the head (n=6), upper limb (n=3), and lower limb (n=2). All lesions were completely excised. Seven patients were alive without evidence of disease (follow-up interval 5 to 24 mo) and 1 patient died of unrelated causes at 7 months without evidence of disease. On histology, the tumors were dermal in location with 2 cases showing focal subcutaneous involvement. Ten tumors were well-circumscribed and 1 tumor showed focally infiltrative edges. Ten tumors revealed conventional BCC associated with varying proportions of osteosarcomatous and undifferentiated sarcomatous stroma. Transition from neoplastic epithelial to mesenchymal cells was seen in 8 cases. One case showed a purely osteoclastic giant cell rich malignant mesenchyme, interpreted as representing early stages of osteosarcomatous transformation. Previously unreported in sarcomatoid BCC, the mesenchymal component of another two cases displayed predominant malignant giant cell tumor like areas and 1 further case disclosed areas reminiscent of telangiectatic osteosarcoma. Pancytokeratins (AE1/3 and MNF116) and smooth muscle actin stained occasional undifferentiated sarcomatous cells in 2 and 3 tumors, respectively. MNF116 and EMA were focally positive in osteosarcomatous tumor cells of 1 case. Although the follow-up interval is short, our data suggest an excellent prognosis for polypoid and exophytic sarcomatoid BCC after complete surgical resection.

Primary cutaneous extraskeletal osteosarcoma under a previous electrodessicated actinic keratosis

Extraskeletal osteosarcoma represents approximately 1% of soft tissue sarcomas and approximately 4% of all osteosarcomas. It is therefore much rarer than osteosarcoma arising primarily in bone. Skin as a primary site has seldom been reported. This report describes an extraskeletal osteosarcoma of the skin under a previously electrodessicated actinic keratosis.

Cutaneous and Subcutaneous Fibrohistiocytic Tumors of Intermediate Malignancy

The fibrohistiocytic tumors of intermediate malignancy are uncommon mesenchymal tumors, which typically occur in the skin and subcutis and which may pose significant problems for the dermatopathologist. This article reviews the clinical, histopathologic, and genetic features of dermatofibrosarcoma protuberans, giant cell fibroblastoma, angiomatoid (malignant) fibrous histiocytoma, plexiform fibrous histiocytoma, and soft tissue giant cell tumor (of low malignant potential). The differential diagnosis of these tumors with a variety of benign and fully malignant cutaneous soft tissue neoplasms is discussed.

A case of extraskeletal osteosarcoma with metastasis to the skin

We present an 83-year-old woman with extraskeletal osteosarcoma (ESOS) of the breast who developed metastasis to the scalp. Skeletal osteosarcoma is the most common primary malignant neoplasm of the bone, predominantly occurring in the metaphysis of the long bones of adolescents and young adults. ESOS, in contrast, occurs primarily in the fifth and sixth decades of life, most commonly in the soft tissue of the thigh. Although the lung is overwhelmingly the most common site of metastasis for both skeletal osteosarcoma and ESOS, the skin is an uncommon metastatic site with only a few reported cases. Metastasis of ESOS to the skin is an exceedingly infrequent phenomenon, which may be a sign of widespread metastases foreboding a grim prognosis.

Primary metaplastic carcinoma (carcinosarcoma) of the skin. A clinicopathologic study of four cases and review of the literature

Metaplastic carcinoma (carcinosarcoma, sarcomatoid carcinoma, malignant mixed tumor) is a biphasic tumor comprising malignant epithelial and heterologous mesenchymal elements. Primary cutaneous cases are rare, with only seven cases documented in the English literature to date. We present four further cases, including three that developed in association with squamous cell carcinoma and one in an eccrine porocarcinoma. Heterologous malignant mesenchymal elements included malignant osteosarcoma, chondrosarcoma, leiomyosarcoma, and rhabdomyosarcomas. In contrast to metaplastic carcinomas arising in visceral sites, those primarily arising in the skin do not appear to behave in a very aggressive manner (Recurrence rate 22%, metastasis rate 22%, overall mortality 11%). However, the numbers involved are small and the follow-up period is short. In view of recent developments and progress in our understanding of the possible histogenesis of such tumors, we suggest that metaplastic carcinoma rather than carcinosarcoma is the most appropriate term with which to describe these very rare cutaneous neoplasms.