Toshimi Hidaka

Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma: A case report with an immunohistochemical study

A rare example of malignant transformation in an ancient schwannoma arisng in the right side of the neck of a 51‐year‐old man without any clinical manifestations suggesting neurofibromatosis is described. The tumor, approximately 4 cm at its largest dimension, was well circumscribed and had a direct connection with the sympathetic nerve. Microscopically, the central portion of the tumor showed features of ancient schwannoma characterized by extensive hyalinization with cystic degeneration, scattered spindle cells with hyperchromatic and tapered nuclei, and some symplastic changes. However, predominantly in the outer portion, a proliferation of spindle‐shaped cells with enlarged nuclei was present. The nuclei of these cells showed irregular contours, coarse granular chromatin texture, and conspicuous nucleoli. Mitotic figures and small necrotic foci with scattered apoptotic bodies were also seen. Immunohistochemically, S‐100 protein was almost negative in areas consisting of overtly atypical cells where the mitotic index evaluated with MIB‐1 antibody was 30.5%. In contrast, S‐100‐positive bland spindle cells were scattered in an extensively hyalinized area with a labeling index less than 3%. P53 protein was strongly positive in atypical spindle cells. Although it is a very uncommon event, definite nuclear atypia, frequent mitotic figures, and the existence of small necrotic foci should be recognized as indicating a diagnosis of malignant degeneration of benign schwannoma. Immunohistochemistry would be useful as an ancillary technique in such a setting.

Congenital Cytomegalovirus Infection and Sensorineural Hearing Loss

Cytomegalovirus (CMV) is the most common cause of congenital viral infection with a reported incidence of 0.29-0.42% of live births. Bilateral and unilateral sensorineural hearing loss of varying degrees has been reported in children with symotomatic and asymptomatic congenital CMV infections. In this paper, case studies from three infants with hearing impairments diagnosed by pediatricians as symptomatic congenital CMV infections are reported. The follow-up hearing assessments were performed by ABR and pure tone audiography. According to their ABR thresholds, the three cases had severe, severe and moderate bilateral sensorineural hearing impairment, respectively. We administered acyclovir and anti-CMV r-globlin, and the ABR thresholds of all three cases improved. However, in two cases, delayed progressive hearing loss and vestibular impairment were found.

Parapharyngeal Space Tumors; A Clinical Study of 7 Cases.

A 67-year-old man was admitted to our hospital because of general fatigue and pancytopenia. The patient had a past history of total laryngectomy for cancer of the larynx at age 64. Following that operation Tegaful 642.0g was administered for about three years. Hematological examinations revealed a hemoglobin of 7.6 g/dl, a white cell count of 2300/μl, and a platelet count of 34000/μl. A diagnosis of myelodysplastic syndrome (RAEB-t) was made from bone marrow, which contained myeloblasts and atypical cells, and peripheral blood cells (65%). A chromosomal banding study of the bone marrow cells was normal. We speculated that the preceding adjuvant chemotherapy was probably related to the occurrence of myelodysplastic syndrome.

Myelodysplastic Syndrome Occurring after Adjuvant Chemotherapy for Laryngeal Cancer.

A 67-year-old man was admitted to our hospital because of general fatigue and pancytopenia. The patient had a past history of total laryngectomy for cancer of the larynx at age 64. Following that operation Tegaful 642.0g was administered for about three years. Hematological examinations revealed a hemoglobin of 7.6 g/dl, a white cell count of 2300/μl, and a platelet count of 34000/μl. A diagnosis of myelodysplastic syndrome (RAEB-t) was made from bone marrow, which contained myeloblasts and atypical cells, and peripheral blood cells (65%). A chromosomal banding study of the bone marrow cells was normal. We speculated that the preceding adjuvant chemotherapy was probably related to the occurrence of myelodysplastic syndrome.