Table 1. Clinical, histological and immunohistochemical features assessed in patients with LCT.
| Clinical |
|
|
| Age |
| Sex |
| Race/ethnicity |
| Age/stage at first histological documentation of LCT |
| Age of death/last follow-up |
| Number and sites of skin and extracutaneous tissue biopsied for lymphoma |
| Serum LDH prior to and at LCT |
| Absolute and percent eosinophils prior to and at LCT |
| Medication history (no., type, and response to therapy) |
|
|
| Histological |
|
|
| Presence or absence of LCT defined as lymphocytes >4× the size of ‘normal’ lymphocytes comprising ≥25% of the entire atypical infiltrate |
| % of all atypical lymphocytes showing large cell morphology |
| Density of infiltrate: estimated number of cells per HPF, assessed as low, moderate, or high |
| Location of infiltrate: specific involvement of epidermis, papillary dermis, reticular dermis, subcutis, follicular epithelium, or sweat gland epithelium |
| Presence/absence of fibrosis: defined by thickened or wiry collagen bundles in dermis |
| Presence/absence of ulceration: defined by full-thickness erosion of epidermis, including basement membrane |
| Epidermotropism: presence of atypical lymphocytes extending into the epidermis, out of proportion to any visible spongiosis |
| Pautrier microabscesses: aggregates of at least 3 atypical lymphocytes in the epidermis, sometimes visibly associated with Langerhans cells, in the absence of the vase-like shapes more typically seen in spongiotic dermatitis |
| Spongiosis: visible intercellular oedema |
| Epidermal hyperplasia: acanthosis/widening of epidermis beyond that expected for the specified region of the skin |
| Eosinophils: quantified by light microscopy, per 5 HPF |
| Neutrophils: present or absent |
| Langerhans cell hyperplasia: present or absent within the epidermis on H&E stain |
| Follicular mucin: intercellular mucin in follicular epithelium, seen on H&E stain, with or without ‘lake-like’ collections |
| Folliculotropism: presence of atypical lymphocytes extending into the follicular epithelium, out of proportion to spongiosis |
| Histopathological stage: tumour vs plaque vs patch (as previously described) |
| Mitotic rate: number of atypical lymphocytes observed to be in mitosis per 5 HPF |
|
|
| Immunohistochemical |
|
|
| CD3 |
| CD4 |
| CD8 |
| CD7 |
| CD4:CD8 |
| % CD30 of total infiltrate |
| Absolute CD30/5 HPF |
| Dermal vs epidermal predominance of CD30 |
| % Ki-67 |
HPF, high power field; LCT, large cell transformation; LDH, lactate dehydrogenase.