Kaposi's sarcoma after T-cell costimulation blockade with abatacept in rheumatoid arthritis: a case report.

WHAT IS KNOWN AND OBJECTIVE: Kaposi's sarcoma (KS) is a malignant neoplasm caused by HHV-8, a pathogen that leads to endothelial cell transformation when host defences are weakened. CASE DESCRIPTION: Here we report the first case of KS during treatment with abatacept, a biologic agent targeting T-cell costimulation. The patient was a 64-year-old female with rheumatoid arthritis who developed multiple firm, purple-reddish nodules on the dorsal aspect of the right hand. Histological examination confirmed KS. WHAT IS NEW AND CONCLUSION: Although a direct causal relationship between KS development and abatacept treatment cannot be proved, we hypothesize a role for costimulation blockade.

Pleomorphic hyalinizing angiectatic tumor of the male breast: a heretofore unreported occurrence.

Pleomorphic hyalinizing angiectatic tumor (PHAT) is considered an unusual mesenchymal tumor of intermediate malignant potential that is distinguished by a prominent angiectatic vasculature with clusters of thin-walled, fibrin-lined vessels surrounded by sheets of spindled and pleomorphic cells. This lesion occurs mostly in the subcutaneous soft tissues of the lower extremities. In this paper, the authors report the first case of PHAT involving the breast parenchyma of a 75-year-old man. The patient was referred to the hospital with a history of a painless left breast mass that had been growing for several years. The lesion did not recur after surgery. The tumor exhibited histopathologic and immunohistochemical features identical to those of a PHAT of other sites. The purpose of this report is to add a rare tumor to the differential diagnosis of mammary spindle cell neoplasms.

Ossifying fibromyxoid tumor with atypical histological features: a case report.

Ossifying fibromyxoid tumor of soft tissues (OFMT) is considered a rare mesenchymal neoplasm. Its main histological features are sheets and ill-defined lobules of rounded bland cells within a fibromyxoid background and a thick collagenous capsule with an incomplete rim of lamellar bone. This lesion occurs mostly in the soft tissues of the lower extremities and limb girdles. In this paper, we describe a mesenchymal tumor removed from the right thigh of a 41 year-old-woman. The neoplasm differed histologically from typical forms of OFMT for areas of moderate cellularity and atypia, nuclear enlargement and small nucleoli. Focally, stromal tongues of osteoid were centrally and irregularly located within the lesion with evident spindling of tumor cells around them. The mitotic activity was low (up to 19 per 50 HPF) and atypical figures were rarely seen. The tumor was positive to S-100 protein, vimentin, CD10, CD56, CD99, ASMA, calponin and collagen IV. Rare elements were positive for cytokeratin AE1/AE3. To the best of our knowledge, this is the first case of atypical OFMT reported to be positive for calponin. The patient is currently alive and well with no evidence of disease at 96 months following surgery. In spite of low-grade histology, OFMT has high local recurrence rate and low metastatic potential, primarily in the lungs, even several years after surgical removal. The recognition of this entity is important. In this report the authors address differential diagnosis and enigmatic histogenesis of this neoplasm.

[Cutaneous angiolipoleiomyoma: a case report and literature review]. / Angiolipoleiomioma cutaneo: segnalazione di un caso e revisione della letteratura.

The Authors describe a rare case of cutaneous angiolipoleiomyoma in an acral location together with a brief literature review. A 62-year-old male presented with a slow-growing asymptomatic nodule, 2.2 cm in diameter, located in the subcutaneous tissue of the left calf. Ten months after surgical excision, the patient is alive and free of disease. Histologically, the lesion was well-circumscribed and contained three components: areas of mature fat tissue were intermingled with cellular areas of spindle eosinophilic cells, reminiscent of smooth muscle cells, and a complex mixture of vessels of different types and sizes. Immunohistochemically, the cellular spindle component was positive for vimentin and smooth muscle actin, and negative for S-100, HMB-45, MART-1 and oestrogen and progesterone receptors. The Authors discuss differential diagnosis with other benign lesions such as angioleiomyoma and subcutaneous angiomyolipoma.

[Myopericytoma-type perivascular myoma located in the soft tissue of the foot: a case report and review of the literature]. / Mioma perivascolare di tipo miopericitoma dei tessuti molli del piede: descrizione di un caso e revisione della letteratura.

We describe a rare case of myopericytoma-type perivascular myoma (MTPM) which arose in acral location and the literature on this field is briefly reviewed. The patient, a 68-year-old man, presented with an enlarging painful nodule, 1.4 cm across, located in the subcutaneous tissue of the right foot. The patient is alive and well 17 months after surgical excision of the nodule. Microscopically, the lesion was well-circumscribed and characterized by a biphasic pattern with a concentric perivascular spindle and ovoid cell proliferation and an extensive hemangiopericytomatous growth component. Immunohistochemically, the neoplastic cells were positive for vimentin, smooth muscle actin, desmin and calponin, negative for S-100 protein, CD34, CD31 and cytokeratins (AE1/AE3, Cam 5.2). Electron microscopy showed electrondense cell bodies suggestive for myopericytic differentiation. The clinico-pathological features of the present case are similar to those previously reported in the literature and we also discuss herein the main histological criteria for the differential diagnosis with other spindle cell and vascular lesions of soft tissues.

[Ganglioneuroma of parapharyngeal space: case report and review of the literature]. / Ganglioneuroma dello spazio parafaringeo: descrizione di un caso e revisione della letteratura.

A case of ganglioneuroma of parapharyngeal space is described and the literature on this field is briefly reviewed. The patient, a 7-year-old female, presented with a left parapharyngeal space mass causing medial displacement of the left lateral pharyngeal wall. The lesion sized 4.4 cm in the largest diameter. Histologically, the tumour showed the coexistence of two distinct cells types--ganglion cells and Schwann cells--within a loose stroma. Immunohistochemically, both cell types were immunoreactive for S-100 protein and negative for cytokeratins.