Monday, 6 December 2010

Lymphocytoma cutis

Lymphocytoma cutis is a benign lymphocyte hyperplasia (B-cell reaction to an antigen such as a red tattoo, Borrelia burgdorferi, injected drug, vaccine) that prefers the head and neck region,and can be associated with sunlight sensitivity. It presents as red or violaceous nodules or plaques and is commoner in females.

It can remain stable or regress over time. Lymphocytoma cutis can be complicated by the development of primary cutaneous B cell lymphoma. Whether the initial diagnosis in such circumstances should have been primary B-cell lymphoma and was missed, or not is uncertain. Lymphocytoma cutis has been classified as a “pseudolymphoma” but there is no need to use the term "pseudolymphoma" whenever specific diagnosis can be made.

The lymphocyte infiltrate affects the reticular dermis rather than the subcutaneous fat (In primary B-cell lymphoma the subcutaneous fat may be infiltrated); it spares the papillary dermis forming a grenz zone. It can be wedge shaped, apex of which is directed at the subcutaneous fat but it does not involve it. However, in
reactions at the site of vaccination, the subcutis is predominantly
affected with little dermal involvement. The infiltrate is considered to be bottom heavy if compared to epidermotropism of mycosis fungoides where there is no grenz zone. Some have sub-typed the lymphocytoma cutis into B-cell or T-cell, according to which lymphoid cell pattern is present on the biopsy. Further divisions within these groups are largely by its cause, if any is identified but many won't follow this classification as it will include distinct conditions under the umbrella term of pseudolymphoma which should be avoided whenever a specific diagnosis can be made. Appendages and blood vessels are spared. The infiltrate is polymorphous (lymphocytes, starry sky macrophages (with tingible/stained bodies), eosinophils and plasma cells). The infiltrate shows a mixture of kappa and lambda light chain positive B cells (polyclonal) by immunohistochemical analysis. Normally, B cells undergo gene rearrangement of one of their immunoglobulin heavy chain genes at an early stage in B-cell development. In lymphocytoma cutis, immunoglobulin heavy chain gene rearrangement polymerase chain reaction or southern blot analysis shows polyclonal rearrangement. CD1a+ dendritic cells (originally observed in the infiltrates of cutaneous T-cell lymphoma) are usually abundant by immunohistochemical analysis. It can contain lymphoid follicles (with germinal centres)[in classic cases] resembling the appearance of lymph node. Differentiation from primary B-cell lymphoma (particularly marginal zone lymphoma “MZL”) can be difficult clinically and histopathologically (presence of atypical lymphoid cells would suggest a primary cutaneous MZL).

A spectrum of B-cell neoplasia ranging from polyclonal lymphocytoma cutis (benign) via oligoclonal and monoclonal lymphocytoma cutis into primary cutaneous B-cell lymphoma (malignant) is possible.

Jessner’s benign lymphocytic infiltration (T-cell infiltrate,  predominantly in the lower dermis and concentrated tightly around blood vessels and within the lymphocytic infiltrate there is no evidence of follicle formation), tumid discoid lupus erythematosus (basal cell liquefaction degeneration with positive direct immunofluorescence), polymorphic light eruption and insect bites reactions are also among the differential diagnoses.

Treatment modalities (no treatment of proven value unless a cause is found and even then elimination of the cause does not necessarily cures the disease, sunscreens are used if there is sunlight sensitivity) include: intralesional steroid injection, topical steroids, oral hydroxycloroquine, intralesional interferon-alpha-2A, and topical tacrolimus. Observation with careful follow-up is a reasonable option.

This page was last updated in September 2014

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Main Works of Reference List (The first eight are my top favourites)

  • British National Formulary
  • British National Formulary for Children
  • Guidelines (BAD - BASHH - BHIVA - Uroweb)
  • Oxford Handbook of Genitourinary Medicine, HIV, and Sexual Health
  • Oxford Handbook of Medical Dermatology
  • Rook's Textbook of Dermatology
  • Simple Skin Surgery
  • Weedon's Skin Pathology
  • A Concise Atlas of Dermatopathology (P Mckee)
  • Andrews' Diseases of the Skin
  • Andrology (Nieschlag E FRCP, Behre M and Nieschlag S)
  • Bailey and Love's Short Practice of Surgery
  • Davidson's Essentials of Medicine
  • Davidson's Principles and Practice of Medicine
  • Fitzpatrick's Colour Atlas and Synopsis of Clinical Dermatology (Klaus Wolff FRCP and Richard Allen Johnson)
  • Fitzpatrick’s Dermatology in General Medicine
  • Ganong's Review of Medical Physiology
  • Gray's Anatomy
  • Hamilton Bailey's Demonstrations of Physical Signs in Clinical Surgery
  • Hutchison's Clinical Methods
  • Lever's Histopathology of the Skin
  • Lever's Histopathology of the Skin (Atlas and Synopsis)
  • Macleod's Clinical Examination
  • Martindale: The Complete Drug Reference
  • Oxford Handbook of Clinical Examination and Practical Skills
  • Oxford Textbook of Medicine
  • Practical Dermatopathology (R Rapini)
  • Sexually Transmitted Diseases (Holmes K et al)
  • Statistics in Clinical Practice (D Coggon FRCP)
  • Stockley's Drug Interactions
  • Treatment of Skin Disease: Comprehensive Therapeutic Strategies
  • Yen & Jaffe's Reproductive Endocrinology