6. MICROSCOPIC EXAMINATION
Sections studied shows
• epidermis with hyperkeratosis, focal acanthosis,
elongation of rete pegs and follicular keratotic plugging.
• the papillary dermis shows dense perivascular and
periadnexal lymphocytic infiltration along with focal
collection of histiocytes and macrophages seen around
degenerated collagen.
• the inflammation is extending upto reticular dermis and
subcutaneous plane.
9. Granuloma annulare
• A benign inflammatory, self-limiting granulomatous
dermatoses that is seen in both adults and children
• Females are more commonly affected than males.
• The lesions involves skin and/or subcutaneous tissue.
10. Granuloma annulare
• The etiology of granuloma annulare is unknown.
• Lesions could be related to insect bites, sun exposure, viral
infections, diabetes, thyroiditis, immunoglobulin-mediated
vasculitis, and certain medications such as antibiotics,
antiinflammatory agents and oral contraceptives.
• Cases have also been reported in patients with AIDS,
sarcoidosis, hepatitis C infection, Hodgkin's and non Hodgkin's
lymphoma, metastatic adenocarcinoma and granulomatous
mycosis fungoides.
11. Histopathology
Histological patterns in Granuloma Annulare:
1. Necrobiotic granuloma.
2. Interstitial or 'incomplete' form - Most common.
3. Granuloma of sarcoidal or tuberculoid type with epithelioid
histiocytes or a type of giant cell - Rare
15. Necrobiosis Lipoidica
• Predominantly involves the dermis.
• Abundant mucin is distinctly
uncommon.
• Multilayered necrobiosis (stacks of
plates) with open ends.
• Thickened collagen bundles within
palisaded granuloma.
• Shows extensive deposits of lipids or
nodular lymphocytic infiltrates in
the deep dermis or subcutis.
• Numerous deep dermal plasma
cells.
16. Rheumatoid Nodule
• Sharp irregular areas of necrobiosis (huge
deposits of fibrin).
• Located in the subcutis and deep reticular
dermis.
• Surrounded by a palisade of elongated
histiocytes.
• Stroma surrounding the nodules show
perivascular lymphocytic infiltrate
including plasma cells.
• Some neutrophils and nuclear dusts of
neutrophils may be present.
• Acute or chronic thrombotic endoarteritis
is observed in some cases around
rheumatoid nodules.
• Old lesions show dense fibrosis, clefts and
cystic degeneration.
17. Special Stains
• Mucin stains such as colloidal iron and alcian blue may be
used to highlight the increased connective tissue mucins.
• Histiocytes gives positivity to vimentin and CD68.