Immunohistochemical differentiation of metastatic tumours

Role of intraoperative touch imprint cytology and immunohistochemistry in the diagnosis of metastatic malignancies in the central nervous system: Cyto-histomorphological findings and differential diagnosis

BACKGROUND

Brain metastases (BMs) are intracranial neoplasms that are more common in adults than primary brain tumors, causing significant mortality and morbidity in cancer patients. This study aimed to evaluate the definitive histopathological diagnosis using touch imprint cytology and the importance and use of immunohistochemistry in the diagnosis of primary origin.

METHOD

Cytological, paraffin section, and immunohistochemical study slides of all metastatic brain tumors consecutively consulted at the pathology department between 2018 and 2023 were evaluated. The sensitivity, specificity, and accuracy of patients' diagnostic results who underwent imprint cytology were compared based on the final diagnosis histopathological report.

RESULTS

A total of 45 patients with and without intraoperative consultation were included in the study. The definitive histopathologic diagnosis and the diagnostic accuracy rate of imprint cytology for distinguishing glial and metastatic tumors on paraffin sections was 100%. Immunohistochemistry was performed in all patients (except one patient; immediate exitus) and histological classification of the primary tumor was performed by analysis of clinical findings and biomarkers. The primary origins of metastatic tumors were often lung and breast, with adenocarcinoma subtype histomorphology, cerebral hemispheres, and discrete foci of metastasis.

CONCLUSION

TPs is a simple and rapid technique that supports diagnosis in intraoperative neuropathology and is a very cost-effective procedure. The pathologist's experience is the key factor in the diagnosis and reduces the need for a frozen section. In our series, the final histopathologic correlation of imprint cytology in the diagnosis of primary and metastatic tumors is 100%.

Papillary hidradenoma of the eyelid margin: clinical and immunohistochemical observations further supporting an apocrine rather than an eccrine origin

A 46-year-old woman was evaluated for a "recurring papilloma" of the left medial upper eyelid margin. Beneath the papillary lesion medial to the punctum was a 5-mm diameter cutaneous mass thought to be cystic. After excisional biopsy, histopathologic analysis documented the presence of an epidermal keratinizing squamous papilloma surmounting a circumscribed dermal papillary hidradenoma composed of deeply eosinophilic columnar cells. Additionally, there was intraductal proliferation of tumor extending toward a subclinical poral opening through the epidermis. Immunohistochemistry proved the apocrine nature of the benign, non-cystic lesion by virtue of its nuclear androgen receptor and cytoplasmic gross-cystic disease fluid protein-15 positivity, along with its smooth muscle actin-positive myoepithelial layer. This and prior cases establish that apocrine tumors, both benign and malignant, are strictly localized at or near the eyelid margin where only apocrine glands are found. These tumors are more often papillary than solid adenomas, and most exceptionally can be malignant. We review the differential diagnosis of simulating eccrine eyelid tumors. We recommend wide local excision for benign lesions, in view of possible intraductal extension that can be eccentric to the main tumor and the miniscule potential for malignant transformation.

Eyelid sebaceous carcinoma: clinicopathologic and multiparametric immunohistochemical analysis that includes adipophilin

PURPOSE

To evaluate the fine cytopathologic features and immunohistochemistry of eyelid sebaceous carcinoma.

DESIGN

Retrospective clinicopathologic study.

METHODS

Clinical records and microscopic glass slides of 12 patients diagnosed with sebaceous carcinoma were reviewed. Paraffin-embedded tissue recuts were immunoreacted for epithelial membrane antigen (EMA), Ber-EP4, p53, Ki-67, and adipophilin for cytoplasmic lipid. Invasive growth and intraepithelial spread were analyzed separately. Cytoplasmic and nuclear characteristics were correlated with the results of the immunohistochemical profiling.

RESULTS

Five patients experienced recurrences, but no metastases or tumor-related deaths were discovered. The nuclei in 11 invasive tumor cells were typically round with finely divided, granular, or smudgy chromatin without prominent margination at the nuclear membrane; they exhibited small punctate nucleoli. Positivity for EMA (both diffuse and focal), p53 (72% of nuclei), and Ki-67 (45% proliferation index) was demonstrated. Adipophilin positivity in vesicular and granular forms was detected in paraffin sections in all invasive tumors, most prominently in moderately differentiated and well-differentiated lesions. Among 9 cases exhibiting intraepithelial extensions, 6 showed mostly granular positivity and 3 vesicular positivity. p53 identified residual atypical intraepithelial cells when conjunctival epithelial sloughing occurred.

CONCLUSIONS

Immunohistochemistry can make significant contributions to the diagnosis of sebaceous carcinoma. p53 and vesicular granular adipophilin positivity were highly reliable in supplementing the routine microscopic diagnosis of infiltrative tumors and both can be used in paraffin sections, thereby obviating cumbersome oil red O staining of frozen sections. The cells found in intraepithelial spread were strongly EMA and p53 positive, with more granular than vesicular adipophilin positivity.

Applying biomarker testing to clinical practice in lung cancer

SUMMARY Until recently, therapeutic options for lung cancer were limited, and the division into non-small-cell lung cancer and small-cell lung cancer and staging of the disease was adequate for treatment decisions in most lung cancer patients. With the discovery of new treatment options, new challenges emerged. This review focuses on recent diagnostic and predictive biomarkers in lung cancer. In addition, new techniques will enable us to perform more molecular analyses in a shorter timespan. These developments require a modern interaction between treating physicians and pathologists for optimal tissue management, allowing more molecular markers to be tested.

Intraosseous carcinoma of the jaws--a clinicopathologic review. Part I: Metastatic and salivary-type carcinomas

This is the first part of a 3-part comprehensive review of intraosseous carcinoma of the jaws. We have outlined 4 groups of intraosseous carcinoma of the jaws (metastatic, salivary-type, odontogenic, and primary intraosseous carcinoma), emphasizing the need for accurate diagnosis and the problems associated with changing classification systems, standardization of diagnostic criteria and nomenclature, and the accuracy of existing literature. In this first part, the features of metastatic and the very rare salivary-type carcinomas of the jaws are examined with particular emphasis on histologic and immunohistochemical characteristics, diagnostic difficulties, and uncertainties.

The challenge of NSCLC diagnosis and predictive analysis on small samples. Practical approach of a working group

Until recently, the division of pulmonary carcinomas into small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) was adequate for therapy selection. Due to the emergence of new treatment options subtyping of NSCLC and predictive testing have become mandatory. A practical approach to the new requirements involving interaction between pulmonologist, oncologist and molecular pathology to optimize patient care is described. The diagnosis of lung cancer involves (i) the identification and complete classification of malignancy, (ii) immunohistochemistry is used to predict the likely NSCLC subtype (squamous cell vs. adenocarcinoma), as in small diagnostic samples specific subtyping is frequently on morphological grounds alone not feasible (NSCLC-NOS), (iii) molecular testing. To allow the extended diagnostic and predictive examination (i) tissue sampling should be maximized whenever feasible and deemed clinically safe, reducing the need for re-biopsy for additional studies and (ii) tissue handling, processing and sectioning should be optimized. Complex diagnostic algorithms are emerging, which will require close dialogue and understanding between pulmonologists and others who are closely involved in tissue acquisition, pathologists and oncologists who will ultimately, with the patient, make treatment decisions. Personalized medicine not only means the choice of treatment tailored to the individual patient, but also reflects the need to consider how investigative and diagnostic strategies must also be planned according to individual tumour characteristics.