Primary cutaneous angioplasmocellular hyperplasia

Expression of Peripheral Node Addressins by Plasmacytic Plaque of Children, APACHE, TRAPP, and Primary Cutaneous Angioplasmacellular Hyperplasia

High-endothelial venules are a common feature of 3 types of cutaneous pseudolymphomas: pretibial lymphoplasmacytic plaque (PLP) of children, acral pseudolymphomatous angiokeratoma of children (APACHE), and T-cell rich angiomatoid polypoid pseudolymphoma (TRAPP). In addition, primary cutaneous angioplasmacellular hyperplasia (PCAH) overlaps with these other 3 conditions. We intend to study the expression of peripheral node addressins in PLP, APACHE, TRAPP, and PCAH. We studied 1 case of PLP, 2 cases of APACHE, 2 cases of TRAPP, and 2 cases of PCAH. Immunostainings for MECA-79 and WT-1 were obtained in all cases. All cases showed a dense lymphohistiocytic dermal inflammatory infiltrate with abundant plasma cells. In addition, HEV were prominent in all cases. Cases of PLP, APACHE, and TRAPP expressed MECA-1. Cases of PCAH did not express MECA-1. Although PLP, APACHE, and TRAPP seem to fall under the same morphologic spectrum with different clinical representations, PCAH seems to be a different entity, with histopathologic peculiarities and a different immunophenotype.

Cutaneous Pseudolymphomas

The term cutaneous pseudolymphoma refers to benign reactive lymphoid proliferations in the skin that simulate cutaneous lymphomas. It is a purely descriptive term that encompasses various reactive conditions with a varied etiology, pathogenesis, clinical presentation, histology, and behavior. We present a review of the different types of cutaneous pseudolymphoma. To reach a correct diagnosis, it is necessary to contrast clinical, histologic, immunophenotypic, and molecular findings. Even with these data, in some cases only the clinical course will confirm the diagnosis, making follow-up essential.

Angioplasmacellular hyperplasia - a new histopathologic clue for anogenital herpes simplex recidivans in immunocompromised patients?

Chronic herpes infections in immunocompromised patients exhibit uncommon features both on clinical and histopathologic levels, which can make correct diagnosis challenging. Better defining histopathologic criteria to identify chronic herpes infection in immunocompromised patients would be of great diagnostic value. In a single-center study, clinical and pathological data of herpes infections confirmed by biopsy was collected. We identified 42 cases overall, of which 21 were from immunocompromised patients and performed a detailed histopathologic pattern analysis of all lesions. In immunocompromised patients, vasculitis was seen in 2/21 cases (9.5%). Involvement of the sweat duct epithelium and/or sebaceous glands was observed in none of the HIV-infected patients but in 5/11 (45.4%) transplant patients with herpes infection. This feature was solely found in patients with acute herpetic lesions (5/5). In the process of histopathologic review, we identified a previously unrecognized morphological pattern of herpes simplex virus infection in immunocompromised patients. The individual clinical history and morphological pattern identified is described for multiple affected patients. In summary, in immunocompromised patients, histopathologic diagnosis of herpes infection can be challenging, in particular in chronic lesions, which lack the presentation of typical herpetic keratinocytes. In our study, we identify angioplasmacellular hyperplasia as a new histopathologic clue, which may be helpful in recognizing chronic herpes infection in immunocompromised patients. Further studies are warranted to implement this clue into routine diagnostics.

Plasma cell granuloma of the oral mucosa with angiokeratomatous features: a possible analogue of cutaneous angioplasmocellular hyperplasia

We report a plasma cell granuloma arising in the movable mucosa of the oral cavity of a 50-year-old man. Histologically, the lesion was characterized by a dense nodular infiltrate of mature plasma cells. Immunostaining for kappa and lambda light chains confirmed a polyclonal plasma cell population. Elongated rete ridges of the overlying epithelium formed collarettes around dilated blood and lymph vessels in focal areas. Based on the overall histologic architecture, we hypothesize that these peculiar changes are secondary to local blood flow alteration with congestive vasodilation caused by a dense plasma cell infiltrate. We believe that the plasma cell population may represent the oral counterpart of the cutaneous angioplasmocellular hyperplasia.