HANDOUT 3 RARITIES

CASE 10: DIAGNOSIS SYRINGOTROPIC CUTANEOUS T-CELL LYMPHOMA

CLINICAL Rare form of cutaneous lymphoma (only ~12 cases reported to date) Mostly males (10/12 cases) Single or multiple scaly patches of plaques Alopecia usual Hypoaesthesia & anhidrosis in some Historical cases of syringolymphoid hyperplasia probably the same thing

PATHOLOGY No epidermotropism Dense lymphocytic infiltrate Hyperplasia and infiltration of sweat duct epithelium Probably a variant of mycosis fungoides Sweat duct infiltration seen in some cases of follicular MF

FURTHER READING Tannous et al. J AM Acad Dermatol 1999; 41: 303 Zelger et al. Br J Dermatol 1994; 130: 765 Ah-Weng et al. Br J Dermatol 2003; 148: 349

CASE 11: ADDITIONAL FINDINGS IMMUNOPHENOTYPE CD3, CD5, CD7, CD8 positive CD2, CD4, CD30, CD45RO, CD56 negative PCR Monoclonal TCR-g re-arrangement

PRIMARY CUTANEOUS CD8-POSITIVE EPIDERMOTROPIC T-CELL LYMPHOMA DIAGNOSIS PRIMARY CUTANEOUS CD8-POSITIVE EPIDERMOTROPIC T-CELL LYMPHOMA

CD8 EXPRESSION IN PRIMARY CTCL Majority of CTCL CD3+CD4+CD8- phenotype CD8 expressed in proportion of cases of well defined entities more frequently CD4+: Pagetoid reticulosis 50% Mycosis fungoides rare CD30+ lymphoproliferations rare CD30- large T-cell lymphoma 12% CD30- small/medium pleomorphic CTCL 21% NO effect on prognosis except perhaps for CD30- small/medium pleomorphic CTCL and only if localised

CD8 TYPICALLY EXPRESSED IN: Subcutaneous panniculitis-like T-cell lymphoma Primary cutaneous CD8-positive epidermotropic cytotoxic T-cell lymphoma

PRIMARY CUTANEOUS CD8-POSITIVE EPIDERMOTROPIC T-CELL LYMPHOMA NO history of previous or concurrent MF Eruptive papules, nodules, tumours Central ulceration Aggressive clinical course Spread to other extranodal sites rather than lymph nodes Median survival 32 months in one recent series

PATHOLOGY Band-like or nodular infiltrates Prominent epidermotropism with follicular and sweat duct involvement Small, medium or large lymphocytes

IMMUNOPHENOTYPE CD3, CD8, TIA-1 positive CD7, CD56 ++/- CD2, CD5 --/+ CD4, CD45RO negative CD7 positive cases said to have poorer prognosis than CD7 negative cases

FURTHER READING Berti et al. Am J Pathol 1999; 155: 483 Agnarsson et al. J Am Acad Dermatol 1990; 22: 569

CASE 12: ADDITIONAL FINDINGS SPINDLE CELLS POSITIVE WITH ANTIBODIES TO: CD45, CD20, CD10, BCL-6 SPINDLE CELLS NEGATIVE WITH ANTIBODIES TO: Cytokeratin, S-100/melanA, CD23, CD35 Pan-actin, SMA, desmin CD34

DIAGNOSIS SPINDLE-CELL B-CELL LYMPHOMA

SPINDLE-CELL LYMPHOMA A pattern of growth NOT a distinct entity Variety of lymphoma subtypes in a variety of sites Often associated with dense fibrous tissue e.g. bone, mediastinum Very rare in absence of sclerosis In skin majority B-cell type and follicle centre cell origin

DIFFERENTIAL DIAGNOSIS Other cutaneous spindle cell tumours True sarcomas – primary or secondary Spindle cell squamous carcinoma Spindle cell melanoma Atypical fibroxanthoma RECOGNITION EASY WITH IMMUNO PROVIDED POSSIBILITY CONSIDERED

CD21 IMMUNOSTAINING Typically used as a marker for FDC (& FDC sarcoma) A normal B-cell differentiation antigen C3d receptor Said not to be detectable in routinely processed, paraffin embedded tissues CAN be detected with newer more sensitive antigen retrieval techniques

FURTHER READING Cerroni et al. Am J Dermatopathol 2000; 22: 299 Goodlad. Br J Dermatol 2001; 145: 313 Wang et al. Histopathology 2001; 39: 476