Primary cutaneous interdigitating dendritic cell sarcoma (IDCS): Report of a new case and literature review.

Interdigitating dendritic cell sarcoma is a very rare entity in the spectrum of histiocytic and dendritic cell neoplasms that mostly occurs in lymph nodes, generally presenting as solitary lymphadenopathy, but may affect every organ. Among extra nodal sites, cutaneous interdigitating dendritic cell sarcoma is exceedingly rare; to date, only 9 cases have been described in English literature. The mean age at diagnosis was 60 years, with a male-female ratio of 1,5 to 1; clinically, two different modalities of skin presentation have been reported: solitary, represented by a single red-brownish nodular lesion, or diffuse, characterized by multiple nodular lesions in one or more body districts. The extreme rarity of this sarcoma and its morphological similarity to other poorly differentiated tumors may lead to a delay in diagnosis; in particular, cutaneous localization may be difficult to differentiate from follicular dendritic cell sarcoma, Langerhans cell sarcoma, poorly differentiated squamous cell carcinoma and more generally sarcomatoid carcinoma, atypical fibroxanthoma, malignant melanoma and several sarcomas. Immunohistochemistry plays an important role in identifying this rare entity and formulating a correct histological diagnosis, fundamental requirement for choosing the best therapeutic approach. We report herein a further case of an 81-year-old Caucasian woman who presented to the Dermatology Department to remove an asymptomatic skin papule in the left temporal region, clinically diagnosed as dermatofibroma. The overall pathological and immunohistochemical features supported the diagnosis of a malignant dendritic cell tumor, consistent of interdigitating dendritic cell sarcoma.

The endogenous cannabinoid system in the gut of patients with inflammatory bowel disease.

Activation of cannabinoid receptors (CBs) by endocannabinoids impacts on a number of gastrointestinal functions. Recent data indicate that CB1 agonists improve 2,4-dinitrobenzene sulfonic acid-induced colitis in mice, thus suggesting a role for the endocannabinoid agonist anandamide (AEA) in protecting the gut against inflammation. We here examined the gut endocannabinoid system in inflammatory bowel disease (IBD) patients, and investigated the ex vivo and in vitro effects of the non-hydrolysable AEA analog methanandamide (MAEA) on the mucosal proinflammatory response. The content of AEA, but not of 2-arachidonoyl-glycerol and N-palmitoylethanolamine, was significantly lower in inflamed than uninflamed IBD mucosa, and this was paralleled by lower activity of the AEA-synthesizing enzyme N-acyl-phosphatidylethanolamine-specific phospholipase D and higher activity of the AEA-degrading enzyme fatty acid amide hydrolase. MAEA significantly downregulated interferon-γ and tumor necrosis factor-α secretion by both organ culture biopsies and lamina propria mononuclear cells. Although these results are promising, further studies are needed to determine the role of cannabinoid pathways in gut inflammation.

Evidence for the intracellular accumulation of anandamide in adiposomes.

Anandamide is a lipid messenger that carries out a wide variety of biological functions. It has been suggested that anandamide accumulation involves binding to a saturable cellular component. To identify the structure(s) involved in this process, we analyzed the intracellular distribution of both biotinylated and radiolabeled anandamide, providing direct evidence that lipid droplets, also known as adiposomes, constitute a dynamic reservoir for the sequestration of anandamide. In addition, confocal microscopy and biochemical studies revealed that the anandamide-hydrolase is also spatially associated with lipid droplets, and that cells with a larger adiposome compartment have an enhanced catabolism of anandamide. Overall, these findings suggest that adiposomes may have a critical role in accumulating anandamide, possibly by connecting plasma membrane to internal organelles along the metabolic route of this endocannabinoid.

["Proximal type" epithelioid sarcoma of the vulva: differential diagnosis with other extrarenal rhabdoid tumors]. / Sarcoma epitelioide di tipo prossimale della vulva: diagnosi differenziale con altri tumori rabdoidi extrarenali.

Proximal type epithelioid sarcoma is a rare neoplasia in which morphological findings are characterized by nodular proliferation of epithelioid cells with focal rhabdoid features. It shares some histological features with other neoplasias and this gives an account of several differential diagnosis with other extrarenal rhabdoid tumors. Immunohistochemical and ultrastructural analysis are important in defining this entity: vimentin, cytokeratin, EMA and often CD34 expression of tumoral cells, moreover ultrastructurally evidence of large paranuclear whorls of intermediate filaments, are requested for diagnosis. A correct diagnostic framing is necessary because of the aggressive clinical behaviour of this tumor, that has a tendency to early spreading. We describe a case of vulvar proximal type epithelioid sarcoma in a 34 years old woman.

Metastasis of breast carcinoma to intracranial meningioma.

A patient who had been treated for bilateral breast carcinoma subsequently developed a metastatic breast lesion in a meningioma. Although it is not uncommon for more than one tumor to occur in the same patient, metastases from one tumor into another tumor are rare (''tumor to tumor'' phenomenon). Meningiomas are the most common primary, intracranial tumors to harbor metastases, the majority of which arise from breast and lung carcinomas. Patients with a history of breast cancer and a solitary, intracranial mass with radiological features consistent of meningioma should be evaluated surgically. The lesion may be a primary cerebral malignancy, a metastatic lesion, or a meningioma with or without a metastatic lesion.

Low-resolution structure of the proteolytic fragments of the Rapana venosa hemocyanin in solution.

Rapana venosa hemocyanin (Hc) is a giant oxygen-binding protein consisting of different subunits assembled in a hollow cylinder. The polypeptide chain of each subunit is believed to be folded in several oxygen-binding functional units of molecular mass 50 kDa, each containing a binuclear copper active site. Limited proteolysis with alpha-chymotrypsin of native R. venosa hemocyanin allows the separation of three functional proteolytic fragments with molecular masses of approximately 150, 100, and 50 kDa. The functional fragments, purified by combining gel filtration chromatography and ion-exchange FPLC, were analyzed by means of small-angle X-ray scattering (SAXS). The gyration radius of the 50-kDa Rapana Hc fraction (2.4 nm) agrees well with that calculated on the basis of the dimensions determined by X-ray crystallography for one functional unit of Octopus Hc (2.1 nm). Independent shape determination of the 50- and 100-kDa proteolytic fragments yields consistent low-resolution models. Simultaneous fitting of the SAXS data from these fragments provides a higher-resolution model of the 100-kDa species made of two functional units tilted with respect to each other. The model of the 150-kDa proteolytic fragment consistent with the SAXS data displays a linear chain-like aggregation of the 50-kDa functional units. These observations provide valuable information for the reconstruction of the three-dimensional structure of the minimal functional subunit of gastropod hemocyanin in solution. Furthermore, the spatial relationships among the different functional units within the subunit will help in elucidation of the overall quaternary structure of the oligomeric native protein.