Background. Alpha‐fetoprotein (AFP) is a useful tumor marker for hepatoma and yolk sac tumor. Recently, elevations of serum AFP were reported in patients with other malignancies, especially gastric cancers. Two distinct tumor morphologies, hepatoid and clear cell, have been correlated with AFP production. Methods. Two patients with AFP‐producing gastric carcinoma were evaluated with immunohistochemical, ultrastructural, and biochemical studies. Results. In Patient 1, the primary and metastatic carcinomas consisted homogeneously of tubulopapillary carcinoma with clear cytoplasm. In Patient 2, the cancer was composed of three different areas: tubulopapillary carcinoma with clear cytoplasm, tumor cartilage, and so‐called hepatoid carcinoma. The morphologic characteristics of tubulopapillary carcinoma with clear cytoplasm were similar to those of the developing gut epithelium at the stage of 2–4 months' gestation. The elution patterns of the serum AFP on lectin‐affinity sepharose column study also suggested a correlation with fetal gut differentiation. Conclusions. AFP‐producing clear cell gastric carcinomas are differentiated into fetal intestine. One patient also had hepatocytic and cartilaginous differentiation, indicative of a blastomatous characteristic of the tumor. These tumors arose in association with intestinal metaplasia.

A surgical case of an aggressive form of adenoid squamous cell carcinoma of the penis was studied. The histological features of the tumor originating from the coronal region of the penis showed a well differentiated keratinized squamous cell carcinoma in the superficial area, which transformed into, with a zone of transition in between, an alveolar structure in the deep invading portion and in the metastatic tumor in the inguinal lymph nodes. The alveolar lining cells exhibited an undifferentiated appearance with prominent nucleoli, frequent mitotic figures, and vascular invasion. These cells were neither dyskeratotic nor acanthotic as described in the literatures. Mucin was negative in the tumor cells and angiosarcoma was ruled out with a sliver impregnation technique. The patient took a rapid downhill course for the ordinary squamous cell carcinoma of the penis, and he expired eight months after penile amputation with a radiological evidence of lung metastasis. These unusual pathological features and an aggressive behavior of this tumor which were not hitherto described for adenoid squamous cell carcinomas necessitated this report. Autopsy was not performed.

Four surgical cases of acquired cystic disease of the kidney in the third decade are reported, which include renal cell carcinoma in three patients and multiple adenomas and cystadenomas in all patients. The intervening parenchyma of these kidneys was disorganized as end stage kidney and numerous cysts were found in both kidneys. Some of the cysts were lined by hyperplastic epithelium consisting of clear and granular cells arranged in piled up and papillary fashion. These cysts were diagnosed as cystadenoma. Multiple solid adenomas of a 28‐year‐old male on hemodialysis for 6 years were of various size as if arranged in developing stage of the growth. Summing up all cases included in the literature, the mean duration of hemodialysis of the cases with renal tumor was 5.2 years, while 2.9 years without tumor. With increase of duration of hemodialysis, acquired cystic disease of the kidney is exposed to a high risk of developing malignancy.

A 57-year-old man presented with a pulmonary mass and subacute onset of paraplegia. Laboratory examination revealed an increased protein content in the cerebrospinal fluid and a normal myelogram. Autopsy disclosed epidermoid carcinoma in the left lower lobe of the lung, intramedullary metastasis at the midthoracic level, and a central pencil-shaped softening above and below the metastatic lesion. The pencil-shaped softening was an ischemic infarct rather than of hemorrhagic or congestive origin. The pathogenesis of this rare association may be explained by the hypothesis of a tumor embolus in the arterial circulation that feeds the center of the cord, producing metastasis. This embolus was followed later by a second embolus to a radicular artery, causing the pencil-shaped softening of the spinal cord.

An autopsy case of a 62-year-old woman with a poorly differentiated, aggressive form of adenoid squamous cell carcinoma arising in the skin overlying the right breast was studled. The tumor, 9 x 8 cm in diameter, had rapidly enlarged since one year before admission from a verrucous lesion of 20 years duration. The histologic features of the tumor showed a welldifferentiated squamous cell carcinoma mainly in the superficial areas, which transformed into, with a zone of transition in between, an alveolar or adenoid structure in the deep invading portion. The adenoid tumor cells exhibited an undifferentiated appearance with prominent nucleoli and frequent mitotic figures. These cells partly showed dyskeratotic or acantholytic features. Much was negative. The patient died at 8 months after the operation.Autopsy revealed widely spreading metastases in which an adenoid structure was outstanding. These unusual pathological features and an aggressive behavior of this tumor, which were hitherto rarely described for adenoid squamous cell carcinoma, seemed to be a poorly differentiated variant of the tumor. This malignant transformation might be derived from loss of cohesion of the pre-existing usual well-differentiated squamous cell carcinoma in the basal and parabasal layers, inparting marked invasiveness of these cells into the supporting connective tissue. ACTA PATHOL.