A Rare Case Report of T-Cell Rich Angiomatoid Pseudolymphoma.

Abstract

Dear Editor, Cutaneous pseudolymphoma (PSL) is a reactive lymphoproliferation that histopathologically and/or clinically imitates cutaneous lymphomas. It can be either B-cell or T-cell predominant, and they are further divided into four main categories. Our case falls under the category of T-cell rich angiomatoid PSL.[1] An 86-year-old male presented with multiple, itchy skin lesions over his face, forearms, back, and legs for the past eight months. He was a known case of type 2 diabetes mellitus and right radical nephrectomy was done for Grade II right clear cell renal cell carcinoma six years ago. Cutaneous examination revealed multiple, erythematous infiltrated papules and plaques over the forehead [Figure 1] and lateral aspect of the face. A few hyperpigmented papules with central crusting were seen over bilateral legs and lower back. Angiolymphoid hyperplasia with eosinophilia (ALHE) and Jessner lymphocytic infiltrate of the skin were considered as differential diagnoses. Histopathology of an erythematous infiltrated papule over the forehead revealed a grenz zone and a fairly defined lesion in the dermis [Figure 2]. Many vascular channels lined by hyperplastic endothelial cells were seen in the lesion. Perifollicular mixed inflammatory cell infiltrates comprising histiocytes, lymphocytes, and a few neutrophils were also seen [Figure 3]. IHC showed lymphocytes with strong membranous staining for CD 3 [Figure 4a], and a few showed CD 20 staining [Figure 4b]. A diagnosis of T-cell-rich angiomatoid PSL was made based on histopathology and IHC.Figure 1: Multiple erythematous, few hyperpigmented infiltrated papules, and plaques seen over foreheadFigure 2: Grenz zone (black arrow) and a fairly defined lesion is seen in the dermis (H and E, 10×)Figure 3: The lesion in the dermis shows many vascular channels lined by hyperplastic endothelial cells (red stars). Perifollicular mixed inflammatory cell infiltrates comprising histiocytes, lymphocytes, and few neutrophils were also seen in the lesion (H and E, 100×)Figure 4: (a) Strong membranous staining of the lymphocytes for CD3. (b) Few lymphocytes show CD 20 staining (IHC)Cutaneous PSL is restricted to cases that histopathologically simulate cutaneous lymphomas but do not fit into any other diagnosis after clinical correlation. Some of the etiological factors of PSL include infections caused by bacteria, viruses, parasites, drugs such as anticonvulsants and antihypertensives, foreign agents such as tattoo dyes, injectable vaccinations, insect bites, and ultraviolet radiation. Cutaneous PSL is divided into four main groups based on histopathologic features and clinical data, which include nodular PSLs, PSLs as simulators of Mycosis fungoides (“pseudo-MF”) and of other CTCLs, other PSLs, and intravascular PSLs. Our case clinically and histopathologically fits into the other PSLs group, which comprises T-cell rich angiomatoid PSL and cutaneous plasmacytosis. Acral Pseudolymphomatous Angiokeratoma of Childhood (APACHE), T-cell-Rich Angiomatoid Polypoid Pseudolymphoma (TRAPP), primary cutaneous angioplasmocellular hyperplasia, and lymphoplasmacytoid plaque (LPP) are all forms of T-cell rich angiomatoid PSL.[1] Our case did not show any eosinophils in the inflammatory infiltrate which are characteristically observed in ALHE and the histopathological features observed in our case does not correlate with Jessner lymphocytic infiltrate of the skin. Histopathologically, APACHE and TRAPP were considered as differential diagnoses, but features were more suggestive of TRAPP. Microscopically, TRAPP shows numerous vessels with plump endothelia, a grenz zone, and a dense dermal infiltrate of lymphocytes with a predominance of CD3 over CD20 cells, as seen in our case. TRAPP usually presents as a solitary polypoidal lesion, but in our case it presented atypically as multiple grouped erythematous papules.[2,3] Review of a series of 19 cases showed that a variety of names have been suggested such as APACHE, TRAPP, angiolymphoid hyperplasia with high endothelial venules (ALH-HEV), etc., for lesions sharing similar features such as vascular proliferation with a dense lymphoid infiltrate. They constitute a spectrum of vascular lesions with considerable histopathological and clinical overlap.[4] A case of PSL of the liver in association with renal cell carcinoma occurring 14 months after right radical nephrectomy has been reported.[5] However, our patient developed PSL of the skin post-nephrectomy. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.