H&E staining of the specimen revealed non-necrotizing, noncaseating granulomatous inflammatory structures comprised of epithelioid cells
and Langhans giant cells with lymphocytic infiltration within reticular dermis, consistent with sarcoidosis (Figure 2).
Histologically, it is characterized by solid sheets or nests of epithelioid cells
with cellular pleomorphism, increased mitotic activity, eosinophilic cytoplasm, vesicular nuclei, and prominent nucleoli.
Upper dermis shows tuberculoid granulomas consisting of epithelioid cells
and multinucle- ated giant cells mainly of Langhans type with sparse or no central caseation within the tuber- cle9 along with abundant lymphocytic infiltra- tion.
At a few places there were sheets of epithelioid cells
. Atypical rounded cells with central nucleus were seen proliferating in the connective tissue mass (Figure 3(a)).
Histological examination showed poorly formed granulomas of epithelioid cells
, Langhans giant cells and lymphocytes within the gallbladder wall.
A lymph node biopsy showed granulomatous lymphadenitis with stellate abscesses surrounded by palisading epithelioid cells
. Serologic testing by indirect IF was positive for C.
Microscopic examination reveals an infiltrative lesion composed of cords, strands, and nests of epithelioid cells
with glassy eosinophilic cytoplasm set in a myxohyaline or sclerotic stroma.
Most cases of MS are benign though 10% of them are malignant with metastasis that is characterized by epithelioid cells
with variably sized nuclei and marked accumulation of melanin in neoplastic cells and melanophages [2, 5].
Activated macrophages transform into epithelioid cells
. Few of the epithelioid cells
fuse to form Langhans giant cells.
Nowadays, GISTs may be defined as morphologically spindle cells, epithelioid cells
, or occasional pleomorphic mesenchymal tumors originating from interstitial cells of Cajal or related stem cell expressing CD-117/C-kit protein in 95% of the cases regardless of the site of origin, histological appearance, and biological behavior.
The skin biopsy in both the cases showed non-caseating perivascular and periappendageal granulomas composed of epithelioid cells
and lymphocytes in the superficial and mid-dermis [Figure 2(a)].
3.: Epithelioid cells
with well-formed vascular lumens, consistent with an epithelioid hemangioma.