Canine Epidermotropic Lymphoproliferative Disease Resembling Pagetoid Reticulosis in Man

Abstract

Abstract. Gross lesions in a dog with cutaneous lymphoproliferative disease involved oral mucosa, and footpad and nasal epithelia. The lesions were vesicles, ulcers, erythematous papules, and plaques. The distinctive histologic feature was the predominantly intraepithelial proliferation of a monomorphous population of atypical mononuclear cells, many with bizarre convoluted nuclei. Ultrastructurally the mononuclear cells had few cytoplasmic organelles and resembled lymphocytes. These features distinguish the lesion from the usual canine cutaneous lymphosarcoma and from the canine equivalent of mycosis fungoides. The histology resembles that of pagetoid reticulosis in man.An unusual form of cutaneous lymphoproliferative disease, resembling mycosis fungoides in man, has been described in the dog [ 14, 16,221. Mycosis fungoides is a tumor of thymus-derived lymphocytes that arises in the skin [ 10,11,17,18]. It is slowly progressive, spreading to lymph nodes and internal organs late in the course of the disease [4,17].Mycosis fungoides has three characteristic histologic features [ 1 1, 171. Firstly, the cutaneous cell infiltrate is pleomorphic, with plasma cells, eosinophils and histiocytes accompanying the neoplastic T lymphocytes. Secondly, many of the neoplastic T lymphocytes have hyperchromatic and convoluted nuclei. The cells have been named mycosis cells [17], although they also occur in inflammatory skin conditions [13]. The third feature, considered almost pathognomonic for mycosis fungoides, is the presence of Pautrier's microabscesses, small intraepithelial clusters of the proliferating tumor cells [17, 181. Pagetoid reticulosis, also known as Woringer-Kolopp disease or epidermotropic reticulosis, is a rare skin tumor in man, considered by many to be another manifestation of cutaneous T-cell lymphoma [2,3,5,9,16,25], perhaps a variant of mycosis fungoides [7, 161. The histiocyte and Merkel cell have been proposed as alternate progenitors [6,20], but recently the tumor cells were shown to have T-lymphocyte membrane properties [3]. Clinically, the disease may be localized or generalized [3, 487 488Johnson and Patterson 251. Histologically, both forms are characterized by the proclivity of the tumor cells to multiply within the confines of the surface epithelium [2,3,5,9,16,251. Case HistoryA 9-year-old female Scottish Terrier had a protracted disease affecting mainly footpad and oral epithelia. The lesions had not responded to intermittent treatment with corticosteroids and antibiotics during the preceding I2 months. Clinical examination showed irregular smooth papules aggregated into plaques on the buccal and pharyngeal mucosa. Over the epiglottis the lesions were vesicular. Well-demarcated irregular plaques on the dorsum of the tongue had a rough grey-white central area with a smooth erythematous periphery. The epithelium on the volar surface of the front and to a lesser extent the rear footpads was irregularly eroded and hemorrhagic. Adjacent areas were covered with thick grey crust. An area of alopeci...

Oral-Cutaneous CD4-Positive T-cell Lymphoma: A Study of Two Patients

“…Interestingly, a pagetoid reticulosis-like process in canines has been described in the veterinary literature, with one case report featuring disease involvement of oropharyngeal mucosa and footpad. 7 The World Health Organization classification of hematopoietic tumors includes ''peripheral T-cell lymphoma (PTCL), unspecified'' as a diagnostic category for mature T-cell neoplasms that do not have unique clinical or molecular features. Although this group primarily incorporates clinically aggressive nodal tumors that frequently infiltrate the skin, the range of clinical behavior is broad and unpredictable.…”

Characterization of a canine long-term T cell line (DLC 01) established from a dog with Sézary syndrome and producing retroviral particles

“…Examination of obvious skin disorders revealed a diffuse cutaneous erythema, scales, crusts and ulceration of the mucous membranes, and of all the mucocutaneous junctions. The complete blood count showed leukocytosis (59 000/mm 3 ) due to lymphocytosis (15 300/mm 3 ) and neutrophilia (39 530/mm 3 ), with a normal distribution of other leukocytes. Examination of cells from biopsy of the mucocutaneous junctions, the skin and the lymph node revealed malignant convoluted T cells.…”

“…Diseases related to MF and SS have been described in dogs. [1][2][3][4][5][6] However, the immunophenotype of the epitheliotropic T cells in canine CTCL are TCR ␥␦ CD8 [7][8][9][10] whereas in human MF and SS, they are TCR ␣␤ CD4 + in the vast majority of cases. [11][12][13][14] Occasional reports of human CD8 + CTCL have also been described, essentially in Pagetoid reticulosis, a rare form of CTCL characterized by a strong epidermotropic lymphoid infiltrate.…”

Canine cutaneous epitheliotropic T‐cell lymphoma with vesiculobullous lesions resembling human bullous mycosis fungoides

“…Another variant of cutaneous epitheliotropic lymphoma in dogs, called pagetoid reticulosis, is described as an exfoliative erythroderma with alopecia, erosions and ulcers without obvious neoplastic masses. Mucocutaneous junctions and footpads are often affected while generalized skin lesions are a common accompanying feature 3,10 …”