A case of soft tissue mesenchymal chondrosarcoma metastatic to skin, clinically mimicking keratoacanthoma

Diagnostic approach to leukemia cutis : A differential diagnostic step-by-step algorithm

OBJECTIVES

Leukemia cutis is a conflicting term to describe neoplastic hematopoietic infiltrates in the skin. Cutaneous myeloid or lymphoid proliferations often present a serious differential diagnostic challenge for pathologists.

METHODS

This review aims to outline the confusion associated with the term leukemia cutis and discuss in detail the foremost common differential diagnoses in daily practice. The review is based on a summary of the relevant literature as well as on the authors' experience.

RESULTS

It addresses precursor cell myeloid and lymphoid tumors that are strictly considered true leukemia cutis but also more mature neoplasms, including some recently described mature extramedullary myeloid proliferations. Finally, a practical, comprehensive stepwise approach combining traditional immunohistochemical marker panels, novel lineage- or mutational-specific markers, and other ancillary tests is suggested to reach an entity-specific diagnosis.

CONCLUSION

The proper combination of ancillary techniques can help the pathologist to provide an accurate diagnosis of these challenging skin lesions.

Keratoacanthoma (KA): An update and review

Keratoacanthoma (KA) is a common but underreported tumor of the skin. Two striking features of KA are its clinical behavior with spontaneous regression after rapid growth and its nosological position on the border between benignity and malignancy. We review current knowledge on the clinical, histopathological, and dermoscopic features of KA to ensure a proper diagnosis and describe its variants, including different types of multiple KAs. We highlight current concepts of KA ethiopathogenesis with special emphasis on the genetic background of multiple familial KA, the role of Wnt signaling pathway, and induction of KA by BRAF inhibitors and procedures of esthetic dermatology. Finally, treatment strategies are presented with surgical excision as a first option, followed by other modalities, including intralesional chemotherapy, topical and systemic agents, lasers, cryotherapy, and photodynamic therapy.

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.

Clinical manifestations of cutaneous metastases: a review with special emphasis on cutaneous metastases mimicking keratoacanthoma

Approximately 5% of oncology patients develop cutaneous metastases, with only a small number of these patients (less than 1%) having metastatic skin lesions as the first sign of their visceral cancer. Metastases tend to occur on skin surfaces in the vicinity of the primary tumor. However, any site may be affected by cutaneous metastases. Skin metastases can present with several morphologies including, albeit rarely, keratoacanthoma-like lesions. Keratoacanthoma is a keratinous tumor that morphologically appears as a nodule with a central keratin-filled crater. This article reviews the characteristics of oncology patients whose cutaneous metastases mimicked a keratoacanthoma, including illustrations from our patient, a 53-year-old Caucasian man whose metastatic esophageal adenocarcinoma not only presented with a keratoacanthoma-like tumor on his upper lip but also a forehead macule and a scalp nodule. We also report keratoacanthoma-like presentations from literature cases of breast cancer, chondrosarcoma, and pulmonary malignancies. The lesions were discovered 3-24 months after diagnosis of visceral cancer and led to the discovery of unsuspected lung cancer in two patients. Most of the patients (60%) died within 2 months of discovery of the keratoacanthoma-like cutaneous metastases. We also reviewed the literature and discuss other morphologies of cutaneous metastases in patients whose primary tumors were in the breast, lung, and esophagus. In addition, we review from the literature other examples of tumors that present as metastatic nodules on the scalp. The possibility of cutaneous metastasis should be entertained and pathologic evaluation should be considered in an oncology patient with underlying visceral malignancy who develops a keratoacanthoma-like lesion.

Molecular approaches to sarcoma therapy

Soft tissue sarcomas comprise a heterogeneous group of aggressive tumors that have a relatively poor prognosis. Although conventional therapeutic regimens can effectively cytoreduce the overall tumor mass, they fail to consistently achieve a curative outcome. Alternative gene-based approaches that counteract the underlying neoplastic process by eliminating the clonal aberrations that potentiate malignant behavior have been proposed. As compared to the accumulation of gene alterations associated with epithelial carcinomas, sarcomas are frequently characterized by the unique presence of a single chromosomal translocation in each histological subtype. Similar to the Philadelphia chromosome associated with CML, these clonal abnormalities result in the fusion of two independent unrelated genes to generate a unique chimeric protein that displays aberrant activity believed to initiate cellular transformation. Secondary gene mutations may provide an additional growth advantage that further contributes to malignant progression. The recent clinical success of the tyrosine kinase inhibitor, STI571, suggests that therapeutic approaches specifically directed against essential survival factors in sarcoma cells may be effective. This review summarizes published approaches targeting a specific molecular mechanism associated with sarcomagenesis. The strategy and significance of published translational studies in six distinct areas are presented. These include: (1) the disruption of chimeric transcription factor activity; (2) inhibition of growth stimulatory post-translational modifications; (3) restoration of tumor suppressor function; (4) interference with angiogenesis; (5) induction of apoptotic pathways; and (6) introduction of toxic gene products. The potential for improving outcomes in sarcoma patients and the conceptual obstacles to be overcome are discussed.