Primary cutaneous diffuse leiomyosarcoma with desmoplasia

Leiomyosarcoma of the skin: review of the literature with an emphasis on prognosis and management

Leiomyosarcoma (LMS) of the skin is rare, and no management guideline currently exists. Although LMS is historically classified as either dermal (cutaneous) or subcutaneous, definition for its classfication is inconsistent in the literature. Studies on the managenent of LMS are scarce, and there is no consensus on the appropriate surgical margin for the treatment of LMS. While a 1 cm margin may be sufficient in cutaneous LMS, wider margins may be required for subcutaneous tumors. Mohs micrographic surgery is a promising surgical modality for the treatment of cutaneous LMS. In this review, current knowledge on LMS is summarized and a practical approach to the management of this rare neoplasm is proposed.

Rapid growing superficial cutaneous leiomyosarcoma of the face

Leiomyosarcomas are uncommon malignant smooth muscle tumors, mainly derived from vessels or viscera. Superficial leiomyosarcomas are a rare soft tissue sarcoma arising from the dermis or subcutaneous tissue in the skin. According to tumor origin and location, they are divided into cutaneous and subcutaneous leiomyosarcoma. They have distinctly different histologic and prognostic features from each other. Superficial leiomyosarcomas show a predilection for the proximal extremities and tend to be slow growing. We report one rare case of superficial cutaneous leiomyosarcoma on the right temporal area of face, which showed an extremely rapid growing mass within 3 months.

Primary desmoplastic cutaneous leiomyosarcoma associated with high MIB-1 labeling index: a teaching case giving rise to diagnostic difficulties on a small biopsy specimen

A case of primary desmoplastic cutaneous leiomyosarcoma is reported. A flat and elevated tan plaque, measuring 30 mm × 20 mm, was noticed in the left back of a 74-year-old Japanese male 6 months before the resection. The biopsy specimen showed an overgrowth of desmoplastic fibrocollagenous stroma, focally admixed with a less cellular proliferation of spindle cells having mildly pleomorphic nuclei, but no mitotic figures, arranged in small clusters or appearing as individual cells. Based on these features, we interpreted it as a benign keloid-like lesion. A local resection was done, and gross examination revealed a poorly demarcated grayish tumor lesion, replacing the entire dermis and extending into the subcutis. Microscopic findings demonstrated a sparsely cellular proliferation of atypical spindle cells having cigar-shaped or multi-nucleated pleomorphic nuclei and abundant eosinophilic cytoplasm with few mitotic hot spots, arranged in interlacing bundles, alternating with scattered tumor cells within an abundant desmoplastic stroma. Immunohistochemically, these atypical cells were positive for α-smooth muscle actin, HHF-35, desmin, and caldesmon, and MIB-1 labeling index was greater than 10%. Therefore, we finally made a diagnosis of desmoplastic leiomyosarcoma as a very rare variant of cutaneous leiomyosarcoma. We should be aware that owing to its characteristic features, pathologists might misinterpret it as benign when examining only small or inadequate specimens. It is thus suggested that a large panel of antibodies including smooth muscle cell markers and MIB-1 in immunohistochemistry are useful and adjunctive diagnostic aids for recognizing malignancy, especially in diagnostically difficult cases such as ours.

Dermal Epstein Barr virus--associated leiomyosarcoma: tocsin of acquired immunodeficiency syndrome in two children

Although rare in childhood, a relatively high incidence of smooth muscle tumors are recognized in patients with AIDS, mainly in association with Epstein Barr virus (EBV) infection. Although EBV-associated smooth muscle tumors have been documented rarely in the subcutis of AIDS patients, dermal involvement has not been described to date. This report describes dermal EBV-associated leiomyosarcomas (EBV-LMS) with a nodular but superficial plaque-like appearance on the lower limbs of 2 males, 9 and 12 years old. Histopathological assessment of the excised lesions demonstrated hypercellular mitotically active dermal tumors with hyperchromatic spindle and round cells, arranged in short fascicles and sheets, with microfoci of necrosis. A smooth muscle immunophenotype, including prominent desmin immunopositivity, and positive EBV-encoded RNA in situ hybridization investigation confirmed a diagnosis of EBV-LMS. Subsequent HIV seropositivity and AIDS were confirmed in both patients. Both patients also had pulmonary tuberculosis and received antituberculous therapy. Patient 1 had a 3 cm re-excision of the prior tumor site. He received highly active antiretroviral therapy, completed 6 months of antituberculous therapy, achieved immune reconstitution and viral suppression and is tumor-free 2 years after tumor excision. Patient 2 died before further therapy. The immune status, presence, and appropriate therapy of co-existent systemic infection and highly active antiretroviral therapy in AIDS patients with EBV-LMS are crucial to a favorable outcome.

Desmoplasia: not always a bad thing

Desmoplasia describes a histological pattern characterized by a hyalinized stroma and a minimal cellular infiltrate. In non-cutaneous neoplasms, this pattern of stromal response is classically associated with malignancy, whereas in cutaneous pathology, desmoplasia is observed in malignant as well as benign neoplasms. Given this, the obvious question is whether desmoplasia associated with a benign neoplasm is any different from that associated with malignant tumours. Is the stromal response a mere epiphenomenon, or does it actually contribute to the biological behaviour of the neoplasm? What happens at the tumour-host interface? Which molecules are involved in mediating the desmoplastic reaction pattern? This review is an attempt to answer these questions. Examples of benign and malignant cutaneous neoplasms associated with the desmoplastic reaction pattern will be included.

Primary leiomyosarcoma of the nipple-areola complex: report of a case and review of literature

Primary leiomyosarcoma of the nipple-areola complex is extremely rare. Less than ten such cases have been reported in English literature so far. Herein we describe a 52-year-old female presenting with a 1.5 cmx1.1 cmx0.7 cm nodular lesion over her left nipple, and leiomyosarcoma was proved by pathological examination of the excised specimen. Positron emitted tomogram (PET) revealed no abnormal signal other than the primary site. Microscopically, this poorly circumscribed tumor was composed of interlacing bundles of smooth muscle cells with bizarre and pleomorphic nuclei, as well as prominent nucleoli. Its mitotic count was up to 7 mitoses per 10 high power fields (HPF). Immunohistochemical study of tumor cells revealed positive stain for alpha-smooth muscle actin and vimentin; and negative for cytokeratin, CD34 and S-100. Left simple mastectomy was undertaken and no residual mass lesion was noted on the resected specimen. Related literatures about the diagnosis and treatment for breast leiomyosarcoma will be presented here.