Case 163. Tuberculosis of skin (13 y-o M)
    Biopsy from the neck skin, accompanying scarring fistula and nodal enlargement    
Key words : Mycobacterium tuberculosis, scrofuloderma, lupus vulgaris
Fibrosing epithelioid granuloma extends into the subcutaneous tissue. The cytoplasm of the epithelioid cells appears to be foamy (HE). Necrosis is only focally seen.   A few acid-fast bacilli are identified within the lesion (Ziehl-Neelsen). "Scrofuloderma" is a form of skin tuberculosis showing secondary fistulous extension from the lymph node or bone.
Reference case 163A
Lupus vulgaris on the face of an 88 y-o female (gross findings). The facial skin is the most common site of reinfection tuberculosis of this form.
  Reference case 163A
Histologic features of lupus vulgaris (HE). Caseous granuloma is observed in the dermis in the biopsy specimen. Caseation is a relatively rare event and bacilli are usually sparse.