Recurrent Cutaneous Angiosarcoma of the Scalp With Aberrant Expression of S100: A Case Report

Intravascular Large B-Cell Lymphoma With Exclusively Cutaneous Involvement, Colonizing Pre-Existing Hemangiomas: A Rare Case With Aberrant HMB45 Expression

ABSTRACT

Intravascular large B-cell lymphoma (IVLBCL) is a rare and aggressive subtype of non-Hodgkin lymphoma. It is characterized by the presence of neoplastic lymphoid cells within blood vessels. We report a rare case of IVLBCL with exclusively cutaneous involvement colonization of hemangiomas. A 55-year-old man with a history of cutaneous angioma consulted dermatology because of the growth of some of the hemangiomas in recent months. Histologic examination revealed a dermal proliferation of small- and medium-sized vessels with lumina occupied by large pleomorphic cells with B immunophenotype and aberrant expression of HMB-45. Biopsy of a pre-existing hemangioma may be useful in the diagnosis of suspected cutaneous IVLBCL. The cutaneous variant has a better prognosis. It is also important to note that unexpected protein expression or loss of expression in malignant tumors may be a risk factor for misdiagnosis.

Primary Undifferentiated/Dedifferentiated Cutaneous Melanomas-A Review on Histological, Immunohistochemical, and Molecular Features with Emphasis on Prognosis and Treatment

Diagnosing cutaneous melanoma is usually straightforward based on these malignancies' histopathological and immunohistochemical features. Nevertheless, melanomas can imitate various other neoplasms, sometimes lacking the expression of conventional melanocytic markers and expressing non-melanocytic ones. Furthermore, divergent differentiation is more often encountered in metastatic melanomas and is still poorly described in primary cutaneous melanomas, and little is known about these patients' prognosis and therapeutic approach. Therefore, we reviewed the literature on undifferentiated/dedifferentiated cutaneous melanomas, and we discuss the histological, immunohistochemical, and molecular profiles of undifferentiated/dedifferentiated cutaneous melanomas to understand these peculiar lesions better and improve their diagnostic algorithm. In addition to this, we also discuss how different genetic mutations may influence prognosis and become potential therapeutic targets.

Kaposi Sarcoma and Cutaneous Angiosarcoma: Guidelines for Diagnosis and Treatment

Kaposi sarcoma is a vascular sarcoma with 4 clinical variants: classic Kaposi sarcoma, which mainly affect the extremities of elderly patients and follows a chronic, generally indolent course; African Kaposi sarcoma; immunosuppression-associated Kaposi sarcoma; and AIDS-associated Kaposi sarcoma. Type8 human herpesvirus is the etiologic agent in all 4variants. Cutaneous angiosarcoma is a cutaneous neoplasm with a very poor prognosis. It carries a high probability of local relapse and has a 10% to 15% survival rate at 5years. There are 3 main variants of cutaneous angiosarcoma: idiopathic angiosarcoma of the face and scalp; Stewart-Treves syndrome; and postradiation angiosarcoma. The only potentially curative treatment is surgery with or without radiotherapy. However, its indistinct borders and multicentric nature mean that treatment is often palliative with chemotherapy, radiotherapy, or both.