Contributed by Anthony J. Demetris, M.D.
PATIENT HISTORY:
Per referral report, the patient is a 40-year-old male with an infected left great toenail, lesion right leg. R/O Kaposi's sarcoma. Review of outside material.

Final Diagnosis (Case 1)

ADDENDUM:
The blocks were requested from the right leg lesion (part B) to search for evidence of Human Herpes virus 8 DNA(by PCR), which has been etiologically associated with Kaposi's sarcoma in some studies, but the evidence is not conclusive at this time, particularly when based on PCR alone. This additional study was done on an experimental basis in an effort to provide further information on this difficult case in which the differential diagnosis between stasis dermatitis and a patch stage of Kaposi's sarcoma on histology alone is difficult.

Although we found the tissue from Part B to be positive for Human Herpes virus 8, even in retrospect, we still favor a histopathological diagnosis of stasis changes. However, close clinical follow-up is recommended.

PART A.
ULCER, LEFT GREAT NAIL BED, INCISIONAL BIOPSY -

  1. EXUBERANT GRANULATION TISSUE WITH FOCAL ULCERATION AND SEVERE ACUTE AND CHRONIC INFLAMMATION.

    PART B:
    RIGHT LEG LESION, BIOPSY -

    1. CHANGES MOST CONSISTENT WITH STASIS DERMATITIS (see microscopic description and diagnostic comment).

    Comment:
    The differential diagnosis between stasis dermatitis and the patch stage of Kaposi's sarcoma is a difficult one. At present, we favor the diagnosis of stasis dermatitis, because of the histopathological findings(see microscopic description) and the clinical history of long standing stasis changes in the lower extremities(as per Dr. Ragni). Additional information which may be helpful in distinguishing between these two possibilities include the detection of the Kaposi's sarcoma virus. If these studies can be carried out on formalin-fixed paraffin-embedded tissue, an addendum report will follow. Dr. Randall Lee also reviewed this case and concurs with the interpretation.

    Previous Biopsies on this Patient:
    None

    TPIS Related Resources:
    None.

    Gross Description - Case 1

    The specimen consists of five (5) consult slides 97 with an accompanying surgical pathology report.

    Microscopic Description - Case 1

    Slide A consists of skin with an acanthotic epidermis showing focal ulceration with underlying granulation tissue containing a severe acute and chronic inflammatory infiltrate, which consists predominantly of mature plasma cells. No definite viral inclusions or definite cytologic atypia is appreciated. The overlying epithelium shows pseudoepitheliomatous hyperplasia and hyperkeratosis with parakeratosis.

    Section B also shows a section of skin with mildly acanthotic epithelium and some flattening of the rete ridges. However, the most striking changes are in the dermis where there is collagenization of the dermal connective tissue. This is intermixed with abundant deposition of pigment, which is apparently hemosiderin. Also present are small lobules of blood vessels which show Factor VIII positivity. Very little inflammatory cell infiltrate is seen. No definite insinuation of endothelial cells between collagen bundles are seen, and no clusters of spindled cells can be appreciated. Moreover, we do not see the characteristic pattern of larger dilated vessels and surrounding, smaller proliferating vessels. Instead, the increase in vascularity seems to be arranged in lobular aggregates, and there is abundant hemosiderin deposition. Based on these findings, a diagnosis of stasis dermatitis is favored over the patch stage of Kaposi's sarcoma at this time.

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