A case of congenital self-healing histiocytosis was studied with S-100 antibody and electron microscopy. Many tumor cells were positive for S-100 protein and a few contained Birbeck´s grandles and dense bodies. A pathlogic fracture was first noticed on the seventh day. The lesions involuted spontaneously by the end of a weeks
Histiocytosis* ; Microscopy, Electron ; S100 Proteins

BACKGROUND: MART-1(melanoma antigen recognized by T cell) is a well-known marker for malignant melanoma. Its immunoreactivity is also expressed in other melanocytic lineage. OBJECTIVE: Our purpose is to evaluate the usefulness of MART-1 in the diagnosis of malignant melanoma. METHODS: MART-1 immunostaining was performed in 26 cases of malignant melanoma and 12 cases of benign melanocytic nevi. HMB-45 immunostaining was performed in 26 cases of malignant melanoma. RESULTS: 1. Eighteen of 26 melanomas(69%) and 10 of 12 benign melanocytic nevi(83%) showed reactivity with MART-1. 2. HMB-45 showed a higher sensitivity(85%) than that of MART-1 in the staining of malignant melanoma. 3. Two of 5 HMB-45-negative melanomas were immunoreactive with MART-1, and 2 of 7 MART-1-negative melanomas were reactive with HMB-45. CONCLUSION:MART-1 immunostaining is not helpful to differentiate malignant melanoma from benign melanocytic nevi. MART-1 was immunoreactive to some cases of HMB-45 negative malignant melanoma. MART-1, together with S-100 protein and HMB-45, is another useful marker of malignant melanoma.
Diagnosis ; Melanoma* ; Nevus, Pigmented* ; S100 Proteins

A schwannoma is a benign neoplasm that is composed of a relative pure proliferation of Schwann cell and constitutes 1% of orbital tumors. Most series report patient age between 20 and 50 year. There was no case report with the schwannoma of nenonate in the domestic and the abroad except two cases in the childhood age group. We experienced a schwannoma which diagnosed by microscopic and immunohistochemical S-100 protein stain in neonate who does not open his eye and present a case with a review of the literature.
Humans ; Infant, Newborn* ; Neurilemmoma* ; Orbit* ; S100 Proteins

An immunohistochemical and electron microscopic study of an atypical fibroxanthoma of the skin (AFX) was reported. The lesion developed on the left scapulararea in a 70-year-old man. The result using antibody to S-100 protein was negative and the tumor cells observed with electron microscope were undifferentiated, fibroblast-like, histiocyte-like and multinucleated giant cells. But Langerhans-like cells or Langerhans were not found.
Aged ; Giant Cells ; Humans ; S100 Proteins ; Skin*

Cellular schwaninoma is a variant of schwannoma, which is characterized by predominance of cellular Antoni A area, presence of mitotic activity, nuclear hyperchromasia, pleomorphism, and absence of Verocay body. These pathologic features often prompted a misdiagnosis of malignancy. However, the clinical outcome has indicated the benignity of the tumor. We have experienced a case of cellular schwannoma arising from right facial nerve with right hemifacial weakness and erosion of mastoid process. Grossly, it was a 3.5 x 3 cm sized and relatively well encapsulated mass with yellowish, friable cut surface. Microscopically, cellular growth with moderate cellular pleomorphism and some mitotic activity (5/40 HPFS, up to 2/HPF) were noted. Immunostaining for S-100 protein showed diffuse strong positive reaction.
Diagnostic Errors ; Facial Nerve* ; Mastoid ; Neurilemmoma* ; S100 Proteins

We report a case of congenital self-healing reticulohistiocytosis in a newborn male, who showed numerous reddish brown papulonodules on the whole of his body and an extremely large tumor mass on the left sole. No extracutaneous involvement was found. All lesions involuted spontaneously within two months. Histopathologically, multiple histiocytes with abundant eosinophilic cytoplasm, multinucleated cells, and eosinophils were observed in the dermis. Immunohistochemical staining with S-100 protein showed positive.
Cytoplasm ; Dermis ; Eosinophils ; Histiocytes ; Humans ; Infant, Newborn ; Male ; S100 Proteins

PURPOSE: To report one case of neurilemoma of the bulbar conjunctiva with a review of the relevant literature. CASE SUMMARY: A 15-year-old girl presented with a bulbar conjunctival mass in the right eye. There were no other medical or ophthalmologic problems. The patient wanted to remove the mass for cosmetic reasons. We performed an excisional biopsy and simple wound closure. The mass was composed of bipolar spindle shaped cells that were arranged in bundles and fascicles in dense fibrous tissue. Immunohistochemical staining for the S-100 protein was positive. Two months after mass excision, there was no evidence of recurrence. CONCLUSIONS: We successfully treated a case of bulbar conjunctival neuriliemoma by simple excision.
Adolescent ; Biopsy ; Conjunctiva ; Cosmetics ; Eye ; Humans ; Neurilemmoma ; Recurrence ; S100 Proteins

Fibrosarcoma of the kidney is rare and usually developed from renal capsule. In the past, this diagnosis was made more frequently and was easily mistaken for leiomyosarcoma. With improved histochemical techniques and a better understanding of mesenchymal derived tumors, the diagnosis of fibrosarcoma of the kidney is made rarely. Microscopically, this tumor discloses fascicular arrangement and herringbone appearance of spindle cells. Positive immunohistochemistry for vimentin along with nonreactivity of tumor cells for cytokeratin, S-100 protein, actin, and CD34 supported the diagnosis of fibrosarcoma. Herein, we report a case of fibrosarcoma of kidney with a brief review of the literatures.
Actins ; Diagnosis ; Fibrosarcoma* ; Immunohistochemistry ; Keratins ; Kidney* ; Leiomyosarcoma ; S100 Proteins ; Vimentin

Primary malignant melanoma arising from the ovarian mature cystic teratoma is extremely rare, with only 31 cases have been described in the literature. It is one of the rarest forms of malignant transformation of ovarian mature cystic teratoma and usually develops unilaterally after menopause. Recently, we experienced a case of primary malignant melanoma arising from ovarian mature cystic teratoma in 71-year-old woman. The diagnosis was confirmed by positive immunohistochemical results of S-100 protein and HMB 45. Here we report the rare case with review of literature.
Aged ; Female ; Humans ; Melanoma ; Menopause ; S100 Proteins ; Teratoma

Papillary eccrine adenoma is a rare cutaneous tumor which occurs most commonly on the distal portion of extremities as a small solitary nodule. Histopathologically, the tumor consists of multiple dilated or branching tubular structures that are lined by two or more layers of epithelial cells and shows papillary projection into the lumina. Positive staining with S-100 protein, CEA, EMA and keratin in papillary eccrine adenoma is consistent with differentiation toward the secretory epithelium of eccrine sweat gland. Herein we report four cases of papillary eccirine adenoma and review the literature.
Adenoma* ; Epithelial Cells ; Epithelium ; Extremities ; S100 Proteins ; Sweat Glands