Undifferentiated tumors: an immunohistochemical analysis on biopsies

Undifferentiated sarcoma of the sphenoid sinus

Paranasal sinuses sarcomas are rare and no treatments have been established. We report a young-adult case of sphenoid sinus sarcoma treated by carbon-ion radiotherapy. The patient presented with progressive left-sided visual impairment. A tumor was then identified and partial resection by transnasal approach was performed. The resected mass showed typical morphology of mesenchymal tumor, and morphological and molecular analyses ruled out a predominant-differentiation phenotype. The pathological diagnosis was undifferentiated sarcoma. The residual lesion was treated with carbon-ion radiotherapy, and tumor progression was absent for one year. The patient died of the tumor regrowth 20 months after initial diagnosis. Although this case had a poorer outcome compared with cases of the more-common sarcoma types, our experience suggested that carbon-ion radiotherapy is potentially beneficial in unresectable undifferentiated sarcomas cases of sphenoid sinus.

Undifferentiated sarcoma of the sellar region

Malignancies lacking specific features of cellular maturation are termed "undifferentiated" and represent 5-10% of all human tumors. They are encountered at a variety of sites but do not, as a rule, arise in the sellar region. A 39-year-old male with a history of testicular seminoma and an unsuccessful biopsy of a third ventricular neoplasm, presented with visual disturbances and memory loss. Light microscopically, the tumor consisted entirely of undifferentiated spindle cells. No germ cell component was noted. An exhaustive immunohistochemical study found immunoreactivity for vimentin and desmin, but for no other myoid markers. Polymerase chain reaction showed no X;18 translocation. Based upon these studies, a diagnosis of "undifferentiated sarcoma" was made. Our case, being highly unusual among reported sellar neoplasms, underscores the difficulties inherent in the differential diagnosis of undifferentiated neoplasms.

Clinico-pathological profile of head and neck malignancies at University College Hospital, Ibadan, Nigeria

INTRODUCTION

This retrospective study analysed head and neck malignancies seen over a 19-year period at the University College Hospital, Ibadan.

METHODOLOGY

One thousand, one hundred and ninety two patients with head and neck malignancies were analysed according to age, gender, topography and histology.

RESULTS

There was an annual hospital frequency of 62 cases per year. The overall mean age for these malignancies was 43.9 (SD ± 19.3) years. The lesions from the respiratory tract were the most frequent (43.2%) of all cases. The palate was the most frequent intra-oral site (13.8%). Epithelial malignancies constituted 73.4% of all cases with a male: female ratio of 2:1, a mean age of 48.1 (SD ± 17.5) years and were mostly located in the larynx (19.7%). Lymphomas constituted 17.5% of all head and neck cancers with a male: female ratio of 1.6:1, a mean age of 35.1 (SD ± 20.6) years and nodal involvement (39.7%) was most common. Sarcomas constituted 8.9% of all malignancies with a male: female ratio of 1.5:1, mean age of 27.1 (SD ± 16.7) years and the maxillofacial bones (42.5%) were most commonly involved. Neuroendocrine malignancies accounted for 0.2% of head and neck malignancies with a male: female ratio of 1:1, a mean age of 28.5 (SD ± 6.4) years and both cases involved the nose.

CONCLUSION

This study has further confirmed that carcinomas remain the most frequent cancers of the head and neck region in south-western Nigeria.

Diagnosis of metastatic neoplasms: an immunohistochemical approach

CONTEXT

It is important to determine the type and/or site of origin of metastatic tumors for optimal clinical management.

OBJECTIVE

To summarize the use of currently available immunohistochemical markers in the evaluation of metastatic tumors.

DATA SOURCES

Review of relevant literature on immunohistochemical evaluation of tumors and the author's personal experience.

CONCLUSIONS

Immunohistochemistry is an important ancillary technique for evaluation of metastatic tumors and should be used in the context of routine morphology and clinical information. While a single marker may be used to support a known or suspected site of origin, a carefully constructed panel is strongly recommended, particularly for tumors of morphologically uncertain lineage or origin.

Undifferentiated tumor: true identity by immunohistochemistry

CONTEXT

"Undifferentiated tumor" refers to a heterogeneous group of neoplasms with little or no evidence of differentiation on routine light microscopic morphology.

OBJECTIVE

To identify the true identity of undifferentiated tumors by immunohistochemical analysis.

DATA SOURCES

Review of the pertinent literature and the authors' experience.

CONCLUSIONS

For treatment and prognostic evaluation, it is crucial to delineate whether an undifferentiated neoplasm is epithelial, mesenchymal, melanocytic, or hematopoietic in nature. Application of a screening panel to demonstrate the expression of markers of major lineages is fundamental for determination of the broad category of neoplasia. Because poorly differentiated carcinomas and in particular sarcomatoid carcinomas are known to be heterogeneous in their antigen expression, several epithelial markers in combination may be required to establish the carcinomatous nature of tumor. A diagnostic misinterpretation as a consequence of occasional aberrant or unexpected antigen expression is best avoided by using a broad panel that includes both antibodies that are anticipated to be positive and those that are expected to be negative. In this treatise, the immunohistochemical dissection of undifferentiated tumors on the basis of their morphologic features is outlined, supplemented with algorithmic immunohistochemical analysis for each morphologic category of small round cell tumors, carcinomatous tumors, sarcomatous (or sarcoma-like) tumors, and tumors with histologically overlapping features, including hematolymphoid malignancies, melanoma, and sarcomas with epithelioid appearance. The utility of several organ- or tissue-specific markers in the context of undifferentiated tumors is reviewed.

Undifferentiated head and neck tumors: the contribution of immunohistochemical technique to differential diagnosis

CONTEXT

Undifferentiated head and neck and skull base tumors are not unusual. They can arise in mucosa as well as in salivary glands, soft tissues or lymph nodes. Suitable therapy and prognosis for each case depends upon precise histopathological diagnosis.

OBJECTIVE

To evaluate the role of immunohistochemical techniques in determining the conclusive diagnosis. The occurrence of these tumors in our service and the way in which they were distributed according to cell pattern, patient's age and tumor location was also evaluated.

TYPE OF STUDY

Cross-sectional study.

SETTING

Hospital das Clínicas, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil.

PARTICIPANTS

43 biopsies performed between January 1990 and December 1997, diagnosed as undifferentiated head and neck tumors.

PROCEDURES

We applied an immunohistochemical panel in accordance with the avidin-biotin-peroxidase complex method. The final diagnosis was achieved after new analysis in conjunction with biopsies stained using the hematoxylin-eosin technique.

MAIN MEASUREMENTS

This study evaluated undifferentiated tumors in head and neck, and the way in which they were distributed, according to cell pattern, patient's age and tumor location.

RESULTS

The most frequent locations for undifferentiated tumors were the lymph nodes, 20.9%; pharynx and neck, 16.3%; paranasal sinus, 14%; and nose, 11.6%. They were most prevalent during the seventh decade of life (34.9%), and twice as prevalent in men as in women. The immunohistochemical technique allowed conclusive diagnosis for 60.5% of the tumors and was suggestive for 20.9% of the biopsies. The most prevalent cell pattern was round cells (51.2%), followed by epithelioid cells (20.9%), spindle cells (16.3%), myxoid pattern (9.3%) and pleomorphic cells (2.3%).

CONCLUSION

Our results demonstrate the fundamental role of the immunohistochemical technique for conclusive diagnosis of undifferentiated tumors.