ES1, a new lung carcinoma antibody--an immunohistochemical study.

AIMS: To characterize a single domain antibody (sdAb), AFAI, obtained by panning a naive phage display library of single domain antibodies against the non-small cell lung carcinoma cell line A549. AFAI recognizes a variant form of carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6 or CEA6). METHODS AND RESULTS: Various normal tissues and 139 neoplastic lesions from lung and other organs were immunostained with ES1 antibody, a pentameric and highly avid form of AFAI. ES1 was immunoreactive with 34 of 35 non-squamous large cell lung carcinomas with staining intensities ranging from focal to extensive and from moderate to strong. Importantly, ES1 stained poorly differentiated lung adenocarcinomas and many undifferentiated large cell lung carcinomas that typically show negative immunoreactivity with an antibody specific for thyroid transcription factor-1. Non-lung adenocarcinomas showed more focal and weaker immunoreactivity than for lung adenocarcinoma. Other carcinomas showed negative or weak immunoreactivity and normal tissues showed no immunoreactivity. CONCLUSIONS: Compared with other antibodies used in the clinical evaluation of lung adenocarcinomas, ES1 is more lung carcinoma sensitive, more sensitive in immunostaining of poorly differentiated adenocarcinomas that are usually associated with distant metastasis and less immunoreactive with normal tissues.

Endometrioid adenocarcinoma of the uterus with a minimal deviation invasive pattern.

AIMS: Minimal deviation adenocarcinoma of endometrioid type is a rare pathological entity. We describe a variant of typical endometrioid adenocarcinoma associated with minimal deviation adenocarcinoma of endometrioid type. METHODS AND RESULTS: One 'pilot' case of minimal deviation adenocarcinoma of endometrioid type associated with typical endometrioid adenocarcinoma was encountered at our institution in 2001. A second case of same type was received in consultation. We reviewed 168 consecutive hysterectomy specimens diagnosed with 'endometrioid adenocarcinoma' specifically to identify areas of minimal deviation adenocarcinoma of endometrioid type. Immunohistochemistry was done with the following antibodies: MIB1, p53, oestrogen receptor (ER), progesterone receptor (PR), cytokeratin 7 (CK7), cytokeratin 20 (CK20), carcinoembryonic antigen (CEA), and vimentin (VIM). Four additional cases of minimal deviation adenocarcinoma of endometrioid type were identified. All six cases of minimal deviation adenocarcinoma of endometrioid type were associated with superficial endometrioid adenocarcinoma. In two cases with a large amount of minimal deviation adenocarcinoma of endometrioid type, the cervix was involved. The immunoprofile of two representative cases was ER+, PR+, CK7+, CK20-, CEA-, VIM+. MIB1 immunostaining of four cases revealed little proliferative activity of the minimal deviation adenocarcinoma of endometrioid type glandular cells (0-1%) compared with the associated 'typical' endometrioid adenocarcinoma (20-30%). The same four cases showed no p53 immunostaining in minimal deviation adenocarcinoma of endometrioid type compared with a range of positive staining in the associated endometrioid adenocarcinoma. CONCLUSIONS: Minimal deviation adenocarcinoma of endometrioid type more often develops as a result of differentiation from typical endometrioid adenocarcinoma than de novo. Due to its deceptively benign microscopic appearance, minimal deviation adenocarcinoma of endometrioid type may be overlooked and may lead to incorrect assessment of tumour depth and pathological stage. There was a tendency for tumour with a large amount of minimal deviation adenocarcinoma of endometrioid type to invade the cervix.

Pagetoid variant of actinic keratosis with or without squamous cell carcinoma of sun-exposed skin: a lesion simulating extramammary Paget's disease.

BACKGROUND: Extramammary Paget's disease usually occurs in anogenital skin. We present five cases of squamous cell carcinoma in situ of sun-exposed skin and non-squamous cell carcinoma in situ actinic keratosis that displayed atypical keratinocytes disposed in intraepithelial cell nests and immunohistochemical staining simulating extramammary Paget's disease. METHODS AND RESULTS: Two pilot cases--one squamous cell carcinoma in situ and one non-squamous cell carcinoma in situ actinic keratosis with formation of intra-epidermal nests of atypical keratinocytes with a pagetoid spread pattern--were encountered at our institution. Fifty-four consecutive cases of squamous cell carcinoma in situ including bowenoid actinic keratosis and 34 cases of non-squamous cell carcinoma in situ actinic keratosis were reviewed to identify pagetoid spread of atypical cells. Representative sections of all cases with pagetoid spread of atypical keratinocytes were submitted for special stains for mucin, and immunostaining for cytokeratin 7 (CK7), cytokeratin 20 (CK20), cytokeratin CAM 5.2 (CAM 5.2), carcinoembryonic antigen (CEA), vimentin and S100 protein. In the group of squamous cell carcinoma in situ, 10 cases displayed pagetoid spread of atypical keratinocytes with cytoplasm ranging from clear to pale and atypical hyperchromatic nuclei. One review squamous cell carcinoma in situ was multicentric with three separate lesions. The atypical keratinocytes tended to form well to poorly defined cell groups extending from the basal cell layer to the corneal layer. No similar cases were identified in the group of non-squamous cell carcinoma in situ actinic keratosis. Two pilot cases and three of 10 review cases with a total of seven separate lesions displayed a moderate to marked immunohistochemical reactivity for CK7 similar to extramammary Paget's disease. CEA immunoreactivity was also detected in two of these cases. In addition, two of 44 squamous cell carcinomas in situ without pagetoid spread of atypical keratinocytes showed a moderate reactivity for CK7 in very occasional atypical keratinocytes. The remaining seven squamous cell carcinomas in situ with pagetoid spread of atypical keratinocytes were not immunoreactive for CEA and CK7. Immunostaining for CK20, vimentin, S100 protein was negative in all atypical cells in all study cases. CONCLUSIONS: Actinic keratosis, particularly squamous cell carcinoma in situ of sun-exposed skin, may have histopathological and immunohistochemical features similar to extramammary Paget's disease and probably represents a variant of actinic keratosis. Awareness of the pagetoid variant of actinic keratosis arising in sun-exposed skin is helpful to avoid the over-diagnosis of extramammary Paget's disease.

Resection margin status in lumpectomy specimens for duct carcinoma of the breast: correlation with core biopsy and mammographic findings.

BACKGROUND: The strategy for surgical treatment of breast carcinoma proven by biopsy is mainly based on the physical and mammographic examinations. To investigate if the pathological findings in core biopsy are contributory to planning the surgical strategy, we correlated the status of ductal carcinoma in situ (DCIS) in the core needle biopsy of breast, the mammographic changes and the status of resection margins in the subsequent lumpectomy. STUDY DESIGN: Consecutive 130 core needle biopsies with prior mammography and subsequent lumpectomy were reviewed. Biopsies were divided into: group I, DCIS; group II, DCIS and infiltrating carcinoma (IC); and group III, IC. Mammographic findings were categorized into four groups: (a) nonspecific findings; (b) calcification (Ca(++)); Ca(++) and mass, and mass only. The status of margins in correlating lumpectomy specimens was reviewed. Close margin was defined as a free margin at less than 0.1cm from the carcinoma. RESULTS: The rates of positive or close margins in three groups I, II, and III were 13/18, 18/48, and 2/64 (P < 0.001); and in mammography groups of nonspecific finding, Ca(++), Ca(++) mass and mass only were 5/6, 7/15, 8/37, and 13/72 (P < 0.001), respectively. Of the total of 14 cases with positive margins of more than 0.5 cm in length, 8, 4, and 2 cases were from group I, II, and II, respectively. In addition, 13 of 21 cases with nonspecific changes or with only Ca(++) in mammograms belonged to the group I; 10 of these 13 cases were associated with positive margins. Forty-one of 72 cases presenting as a mass only in mammograms belonged to the group III; only 2 of these 41 cases were associated positive margins. CONCLUSIONS: Correlation of the extent of carcinoma with pre-operative histopathological findings was better than with mammography. Core biopsies containing only DCIS, particularly in cases with nonspecific findings or with only Ca(++) in mammograms, represent a group of breast carcinoma that pose the high risk for incomplete resection in lumpectomy. Surgical management of patients having these cores includes wider resection margins than would otherwise be taken. Most core biopsies with only IC were associated with negative margins.

Ret oncogene protein expression in papillary thyroid carcinoma and related lesions.

BACKGROUND: Activation of Ret oncogenes, particularly Ret/PTC, has been identified in papillary thyroid carcinoma (PTC). The purpose of this study was to investigate the immunostaining pattern of Ret oncogene protein in PTC and nodular non-PTC lesions with a fine chromatin pattern. MATERIALS AND METHODS: Ninety-three PTC and 139 nodular non-PTC lesions were microscopically reviewed to identify the nuclear changes of "limited nuclear features of PTC" (focal nuclear grooves, nuclear inclusions or optically clear nuclei) and areas of infiltrating carcinoma (IC) and were submitted for immunostaining with Ret oncogene protein antiserum. RESULTS: Immunoreactivity for Ret protein ranged from negative in follicular adenoma (FA) with a coarse chromatin pattern, to negative or weak reactivity in FA with a fine chromatin pattern, to strong reactivity in PTC with areas of infiltrating carcinoma (IC). In FA with fine chromatin, FA and follicular carcinoma (FC) containing an admixture of areas of coarse and fine chromatin, areas with nuclear changes with "limited nuclear features of PTC" displayed varying degrees of immunoreactivity. The intensity of immunostaining varied with the degree of nuclear change. The noninvasive component of PTC with IC usually showed more extensive and stronger reactivity than PTC without IC. PTCs with and without IC were associated with a rate of lymph node metastasis of 48% and 3%, respectively. CONCLUSIONS: The expression of Ret oncogenes (Ret/PTC, other unknown variants or wild type) is focally or extensively present in all PTC with IC. The degree of immunoreactivity is likely to be proportional to the potential for lymph node metastasis of PTC. In the context of this study and due to the specificity of Ret oncogenes, it is likely that nodular non-PTC lesions with a fine chromatin pattern and focal positive reactivity for Ret oncogene represent PTC-related lesions.

Glomus tumor of the trachea.

Extracutaneous glomus tumors are uncommon and rarely occur in the trachea. We describe a 73-year-old man with a glomus tumor of the trachea who presented with cough, dyspnea, chest pain, and hemoptysis. A curative segmental tracheal resection with primary reconstruction was performed with no recurrence at 6-year follow-up. The clinicopathologic features of this unusual neoplasm are discussed with a review of the literature.

Fine needle aspiration biopsy of epithelioid angiomyolipoma. A case report.

BACKGROUND: Epithelioid angiomyolipoma (AMYL) is a variant of angiomyolipoma characterized by sheets of epithelioid cells that may mimic renal cell carcinoma. This is the first report describing the fine needle aspiration biopsy features of this lesion. CASE: A 47-year-old man with a history of epithelioid angiomyolipoma of the kidney treated with nephrectomy nine months previously presented with a recurrent retroperitoneal mass and multiple nodular liver lesions. Fine needle aspiration biopsy of one of the liver lesions showed fragments and sheets of noncohesive epithelioid cells with thin cytoplasm, markedly atypical nuclei, and scattered bizarre and multinucleated forms. The epithelioid cells focally expressed HMB-45 and were nonimmunoreactive, with epithelial markers. CONCLUSION: Epithelioid AMYL may pose differential diagnostic problems with high grade carcinoma, especially renal cell, hepatocellular and metastatic carcinoma. An awareness of this entity and its characteristic cytologic features and immunoreactivity with HMB-45 is helpful in its identification.

Incidental prostatic adenocarcinomas and putative premalignant lesions in TURP specimens collected before and after the introduction of prostrate-specific antigen screening.

BACKGROUND: Since the introduction of prostate-specific antigen (PSA) screening for the detection of prostatic adenocarcinoma (PCA), there has been an increase in the incidence of stage T1c PCA. The purpose of this study was to compare the frequency of incidental PCA found in transurethral resection of prostate (TURP) specimens for a 14-month period during 1989-1990 (before PSA screening was available) with the incidence of PCA for a 32-month period during 1997-1999 (after PSA screening became available). DESIGN: Consecutive TURP specimens from the 2 time periods were reviewed to identify incidental PCA, prostatic intraepithelial neoplasia (PIN), and atypical adenomatous hyperplasia (AAH). Cases of TURP for palliative treatment of known advanced PCA were excluded from the study. All TURP specimens were fixed in 10% buffered formalin and were processed according to the same protocol. RESULTS: We reviewed 533 and 449 TURP specimens for the time periods 1989-1990 and 1997-1999, respectively. Comparison of the results for these 2 time periods revealed that the combined prevalence of T1a and T1b PCA decreased over time from 12.9% to 8.0% (P =.06) with the introduction of PSA screening. A new group of T1c PCA was established in the post-PSA screening period of 1997-1999. There were no statistically significant differences in the incidences of T1a PCA, PIN, and AAH in TURP specimens for the 2 time periods. CONCLUSION: The decreased incidence of T1b PCA in TURP specimens for the 1997-1999 period represents a shift in PCA staging. Some PCAs previously staged as T1b are now staged as T2 carcinomas, as a result of PSA screening and earlier clinical detection. The introduction of PSA screening has had no influence on the incidence of T1a PCA, PIN, or AAH in TURP specimens.

Immunohistochemical study of papillary thyroid carcinoma and possible papillary thyroid carcinoma-related benign thyroid nodules.

Recent immunohistochemical studies have identified different antisera that have various degrees of sensitivity and specificity for papillary thyroid carcinoma (PTC). In this study, we performed immunostaining for CK, EMA, HBME, CD57 and CD15 in PTC, and benign thyroid nodular lesions to compare the sensitivity and the specificity of these antisera for PTC. In addition, we studied the patterns of immunostaining of these antisera in benign nodular thyroid lesions displaying a fine chromatin pattern, foci of cells with nuclear grooves, and optically clear nuclei. Fifty-five PTC (composed of 30 papillary variants and 25 follicular variants), 5 follicular carcinomas, 30 follicular adenomas, and 20 thyroid nodular lesions (5 papillary variants and 15 follicular variants) were submitted for immunostaining with CK, EMA, HBME, CD57, and CD15. CK and HBME showed the highest sensitivity and specificity for PTC when an arbitrary cutoff of more than 10% positive cells was considered as positive diagnostic immunostaining for these sera. The other antisera were less sensitive and less specific. One case of PTC showed negative HBME but positive CD15, whereas three papillary variants and two follicular variants of benign thyroid nodules revealed a positive diagnostic HBME immunostaining for PTC and negative CK immunostaining. Any combination of positive diagnostic immunostaining with CK+ HBME, CK+ CD57 or CK+ CD15 has a sensitivity of 95% and specificity of 90% for PTC. Thyroid nodules with a diffuse or focal fine chromatin pattern and focal areas with nuclear grooves or optically clear nuclei displayed immunoreactivity ranging from 0% to 50% of cells. Three of five follicular carcinomas showed negative reactivity for HBME, CD57, and CD15. A combination of immunostaining with CK, HBME and CD57 (or CD15) is a sensitive and specific test for PTC. This panel can be used to rule out thyroid nodules posing a diagnostic problem with PTC. Follicular adenoma and nodules of the thyroid, with a fine chromatin pattern and focal nuclear grooves or optically clear nuclei, displayed an intermediate range of reactivity between reactive thyroid tissue and PTC.

Papillary thyroid carcinoma and related thyroid neoplastic lesions: a light microscopic study with emphasis on nuclear changes.

A total of 187 thyroid lesions consisting of 2 cases of Grave's disease, 21 cases of multinodular goiter, 40 follicular adenomas and 124 low-grade papillary thyroid carcinomas were studied to identify intermediate neoplastic lesions in the spectrum of nuclear changes between benign reactive thyroid follicles and low-grade thyroid papillary carcinoma. The lesions were examined and classified on the basis of the following nuclear features: fine chromatin seen in the thyroid papillary carcinomas and coarse chromatin seen in follicular carcinomas. Cases with Hürthle cell changes were excluded from the study. Cases with nuclei containing coarse chromatin were classified in the group of follicular adenomas with a coarse chromatin pattern. The neoplastic thyroid lesions containing fine chromatin showed a spectrum of nuclear changes ranging between reactive follicular lesions and papillary thyroid carcinoma with lymph node metastasis. Such lesions were classified as follicular adenomas with a fine chromatin pattern. The nuclei of these lesions were graded into mild to marked "nuclear atypia with a fine chromatin pattern". The degree of atypia depended on the degree and extent of nuclear changes. Encapsulated follicular adenomas with a fine chromatin pattern and with mild atypia (11 cases), moderate atypia (13 cases), marked atypia (27 cases), and encapsulated or nonencapsulated papillary thyroid carcinoma were characterized by uniform nuclei; with mild, moderate and marked nuclear atypia in less than 2/3 of the cell population and marked nuclear atypia in more than 2/3 of the cell population; and measuring 5.4-6.3, 6.0-7.2, 6.3-9 and 7.2-10 microns in diameter, respectively. Follow-up of cases of papillary thyroid carcinoma fulfilling the above criteria showed lymph node metastasis in 33% of cases, whereas follicular adenomas with a fine chromatin pattern, including cases originally diagnosed as papillary carcinoma, showed no evidence of lymph node or distant metastasis in a follow-up period of 30 months to 15 years. In the thyroid tissue surrounding papillary thyroid carcinoma or encapsulated follicular adenoma with a fine chromatin pattern and marked atypia, adenomatous nodules with a fine chromatin pattern and with low-grade nuclear atypia were identified. The adenomatous nodules with a fine chromatin pattern and with mild, moderate and marked atypia showed architectural, cytoplasmic and nuclear features similar to those of follicular adenoma with a fine chromatin pattern of the same grade. Of interest, a large number of cases of follicular adenoma with a fine chromatin pattern had areas with features of follicular adenoma with a coarse chromatin pattern.

Pattern of distribution of intraductal and infiltrating ductal carcinoma: a three-dimensional study using serial coronal giant sections of the breast.

The purpose of this study was to establish the 3-dimensional (3D) structure of the breast tissue and to study the distribution and relationship between the intraductal and infiltrating components of ductal carcinoma and other proliferative epithelial lesions of the breast. Thirty mastectomy specimens with infiltrating carcinoma less than 3.0 cm in diameter were serially cut in the coronal plane. Each giant section was divided into small sections for routine processing. Using Photoshop (Adobe) and PowerPoint (Microsoft) software programs, the routinely stained sections were scanned and assembled to reestablish complete giant sections of the breast and subsequently the 3D structure. Intraductal and infiltrating ductal carcinomas, epithelial hyperplasia with atypia, and marked epithelial hyperplasia without atypia were mostly confined to a single duct (27 cases), resulting in an increase in size of the involved breast segment. Three remaining cases included a case of Paget's disease with tumor appearing to spread from one duct system to another system through the epidermis and two cases with multiple separate foci of carcinomas located in different quadrants and accompanied by ductal spread in different lactiferous ducts. Both intraductal and infiltrating carcinomas were often located in the superficial segments (near the subcutaneous tissue) (28 cases). The infiltrating components were often located adjacent to area of pure intraductal carcinoma and were often peripheral (nearer the chest wall than the nipple). Intraductal carcinomas showed a "fanned out" pattern of distribution, frequently extended toward the nipple (with involvement of the nipple or subareolar tissue in 7 cases), and occasionally were seen in the breast tissue peripheral to the infiltrating carcinoma. Multiple ducts with intraductal carcinoma could be seen to be connected with each other with serial sections. However, in at least 6 cases, foci of intraductal carcinomas were separated from each other by segments of duct with benign epithelium. Breast carcinoma often arise from the breast segment close to the subcutaneous tissue. Infiltrating carcinoma lesser than 3.0 cm in diameter is usually located adjacent to the area of pure intraductal. The pattern of spread of intraductal carcinoma has a pyramid-like shape, with the summit toward and occasionally extending up to the nipple. These findings should be considered in the surgical strategy for segmental resections of breast carcinomas.

Mammary Paget's disease: evidence of diverse origin of the disease with a subgroup of Paget's disease developing from the superficial portion of lactiferous duct and a discontinuous pattern of tumor spread.

The pattern of spread of intraductal carcinoma associated with mammary Paget's disease has not been well studied. The purpose of this study was to examine the site of origin and the pattern of tumor spread with a three-dimensional view by serial sectioning of the tissue blocks from 19 cases of Paget's disease. Intraductal carcinoma in the superficial portion of the lactiferous ducts was seen in continuity with the overlying epidermis with Paget's disease in all 19 cases. In seven cases that had adequate tissue sampling, five showed a continuous pattern of the intraductal carcinoma within the superficial as well as the deep breast tissue. In the remaining two cases, a portion of benign duct was identified between the intraductal carcinoma in the superficial lactiferous duct and the deep breast tissue. This discontinuous pattern of spread of the intraductal carcinoma was also identified in the foci of carcinoma in deep tissue. In the five cases in which the tumor involved the skin and only the superficial portions of the lactiferous duct, the leading edge of the intraductal carcinoma was seen orientated in the direction of the nipple towards the deep breast tissue. Our study of Paget's disease demonstrated that in addition to tumor spread along the lactiferous ducts from intraductal carcinoma in the deep tissue towards the nipple, there was a group of Paget's disease arising from the nipple. These lesions included: (i) lesions limited to the areolar tissue; and (ii) lesions with intraductal carcinoma involving the duct system in both superficial and deep breast tissue with and, possibly, without skip areas pattern of spread. Although certain cases of Paget's disease may appear superficial, an independent associated carcinoma in deep breast tissue has to be ruled out.

Neoplastic non-papillary thyroid carcinoma lesions with a fine chromatin pattern.

In papillary thyroid carcinoma (PTC) in cytological and surgical specimens, fine chromatin, nuclear grooves and nuclear pseudoinclusions are the hallmarks of diagnosis. We investigated the significance of these nuclear changes in neoplastic non-PTC lesions. Fine needle aspiration biopsies (FNAB) of thyroid lesions were reviewed with histologic correlation. Twenty-five low-grade PTC and 35 neoplastic non-PTC lesions with a fine chromatin pattern in cytology specimens were identified. These lesions were studied along with five multinodular goiters and five follicular adenomas with a coarse chromatin pattern. The neoplastic non-PTC lesions were selected from cases with a histopathologic diagnosis of follicular neoplasm (accompanied by cytopathologic examination) but lacking a coarse chromatin pattern. The nuclear changes were separated into three grades of nuclear atypia with a fine chromatin pattern, depending on the degree of nuclear enlargement and nuclear membrane thickening, or the presence of nuclear grooves or pseudoinclusions. Thyroid lesions with a higher grade of nuclear atypia with a fine chromatin pattern were associated with larger nuclei and more readily visible nucleoli. These lesions correlated histologically with PTC and follicular adenomas with a fine chromatin pattern. The latter could be divided into three grades: grade 1 lesions having a fine chromatin pattern similar to that of nuclei with open chromatin seen in areas of nodular goiter; grade 3 lesions having nuclear features closest to those of PTC; and grade 2 lesions showing intermediate changes. In conclusion, there is a spectrum of nuclear changes in neoplastic non-PTC lesions with a fine chromatin pattern. These lesions are often diagnosed as follicular adenomas in surgical pathology and pose cytopathologic diagnostic problems between nodular goiter, follicular adenoma and PTC. The significance of follicular adenomas with a fine chromatin pattern will be discussed.

Adenomatoid tumor of the genital tract: evidence of mesenchymal cell origin.

The objective of this study was to re-examine the histogenesis of adenomatoid tumors. This benign neoplasm is characterized by gland-like structures with a pseudodinfiltrative pattern, usually involving fibromuscular tissue at a certain distance from an overlying surface mesothelium. Twenty cases of adenomatoid tumors and four cases of reactive submesothelial lesions, characterized by marked proliferation of subserosal mesenchymal cells, were reviewed. Nineteen of twenty adenomatoid tumors, including lesions with ill-defined borders, showed no connection with surface mesothelium. At the periphery of small tumors, isolated glands, clusters of epithelioid cells and single epithelioid, and spindled cells showing no connection to adjacent glands or cell clusters were identified. The tumor cells shared features with reactive subserosal stromal cells including an infiltrative pattern and histochemical and immunohistochemical properties. The differences between adenomatoid tumors and reactive submesothelial tissue are quantitative in nature: predominant amount of spindled cells in reactive submesothelial lesions, and predominant amount of gland-like structures in adenomatoid tumors. It is proposed that adenomatoid tumors arise from pluripotent mesenchymal cells that differentiate toward submesothelial cells and eventually mesothelial cells. This differentiation is probably induced by the adjacent submesothelial cells.

Basaloid carcinoma of the lung with bronchiolo-alveolar cell differentiation. A case report.

AIMS: We report a case of pulmonary basaloid carcinoma with bronchiolo-alveolar cell differentiation. PATIENTS AND RESULTS: A 75 year-old presented with a tumor measured 2.0 cm and was located in the periphery of the left upper lobe. Histologically, the lesion consisted of nests of basaloid cells, and lumina and clefts lined by tumor cells with features of mucous cells or type II pneumocytes or with mixed features. CONCLUSIONS: Previously reported basaloid carcinomas of the upper aero-digestive tract and lung have been purported to have an aggressive behavior. The tumor in the present study had features of a histopathological low grade tumor including a low mitotic rate, no tumor necrosis and a growth pattern at the periphery similar to that of bronchiolo-alveolar carcinoma.

Composite renal cell carcinoma and angiomyolipoma: a study of the histogenetic relationship of the two lesions.

The purpose of the present study was to investigate the possible histogenetic relationship of renal cell carcinoma (RCC) and angiomyolipoma (AMYL) occurring in the same renal nodule by examining two cases of composite RCC and AMYL in patients without stigmata of tuberous sclerosis and by reviewing the medical literature of similar cases. Case 1 represents an epithelioid variant of AMYL with multiple additional nodules of typical AMYL in a surgically removed kidney. The patient subsequently developed a lesion consisting of a mixture of epithelioid variant of AMYL and RCC 24 months later in the retroperitoneum and, an additional 4 months later, in the liver. The RCC cells resembled mononucleated epithelioid cells of the epithelioid AMYL except that they were focally reactive with epithelial membrane antigen (EMA) in the retroperitoneum and focally reactive with both EMA and cytokeratin (CK) in the liver. Case 2 consisted of a typical AMYL admixed with a chromophil cell RCC. A review of the medical literature revealed seven additional cases with histopathological findings similar to this case. All cases had multiple foci of typical AMYL. Immunostaining results are available in five tumors. Chromophil RCC showed variable reactivity with CK and EMA. In addition, RCC in the two cases in the present study also displayed a positive reaction with mucin staining and a positive reactivity with carcinoembryonic antigen. There appears to be a spectrum of histopathological and immunohistochemical changes from the epithelioid variant of AMYL through a mixed epithelioid AMYL/RCC to chromophil RCC in three successive specimens in case 1. Moreover, the intimate admixture of AMYL and RCC and the similar expression of epithelial markers of RCC in the two cases in the present study, as well as other cases in the literature, suggest that some RCC develop from the same precursor cell as AMYL or from a component of AMYL.