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The Pathohistology Laboratory at Nadezhda Hospital
“Pathology is the core unit where the diagnostic process takes place — it is here that the final diagnosis is established, determining the therapeutic strategy.” Interview with Dr. Dimitar Metodiev.
05.01.2026 | 10:10
The Pathohistology Laboratory is a specialized unit at Nadezhda Hospital that provides tissue and cytological diagnostics — a key step in establishing a definitive medical diagnosis and ensuring successful treatment.
All types of tissue and cellular materials obtained through biopsies, surgical interventions, and diagnostic procedures are examined here. The team’s conclusions provide precise information about the nature of the disease, its stage, and its prognosis, which are crucial for selecting the appropriate therapeutic approach. Behind every result stands the team’s expert experience and world-class technological equipment, which together ensure that patients receive the most reliable foundation for their treatment.
To discuss the work and role of the Pathohistology Laboratory at Nadezhda Hospital, as well as the opportunities it provides, we speak with its Head, Dr. Dimitar Metodiev.
Dr. Dimitar Metodiev graduated in Medicine from Medical University – Sofia in 2009. In 2016, he obtained his specialty in General and Clinical Pathology and Cytopathology, following advanced training in General and Clinical Pathology.
Since 2012, he has served as an assistant and later as a lecturer for Bulgarian- and English-speaking medical students at the Faculty of Medicine of Sofia University St. Kliment Ohridski in Sofia. In 2013, he won a competitive position as an assistant in the Department of Forensic Medicine and Deontology at Alexandrovska University Hospital.
Since 2022, Dr. Metodiev has been pursuing independent doctoral research at the Department of Neurosurgery of St. Ivan Rilski University Hospital in Sofia, where he is developing a dissertation focused on neuropathology in cases of pharmacoresistant epilepsy.
From 2017 to the present, he has been working in the Pathohistology Laboratory of Nadezhda Hospital, and since June 2023 he has led the department. His scientific interests include gynecological pathology and placental disorders, neuropathology, gastrointestinal pathology, and dermatopathology.
1. Dr. Metodiev, you are the Head of the Pathohistology Laboratory at Nadezhda Hospital. What does the laboratory’s work involve?
Our main activities include morphological diagnostics of biopsy materials, cytological examinations, and intraoperative consultations (frozen sections). Pathology is the central unit where the diagnostic process is realized — it is here that the final diagnosis is established, determining the therapeutic strategy. Neoplastic processes differ significantly, and therefore treatment approaches must also differ. These decisions are based on our detailed diagnoses.
2. What kind of team works in the laboratory? Given the shortage of professionals in this medical specialty, is the department at Nadezhda Hospital adequately staffed?
Our team consists of physicians specialized in General and Clinical Pathology, highly qualified laboratory technicians, and technical staff. Despite the nationwide shortage of pathology specialists, we have managed to maintain a stable and motivated team.
This is due to efficient work organization, modern equipment, and the professional development opportunities offered by Nadezhda Hospital. We encourage continuous education, exchange of expertise, and the annual implementation of new diagnostic approaches.
3. Does the laboratory’s equipment meet all standards required to guarantee result accuracy?
Our equipment is on par with leading European and global laboratories. We have automated tissue processors, high-precision microtomes (including semi-automated systems), immunohistochemistry instruments, a cryostat for intraoperative diagnostics, and advanced light microscopes capable of capturing images of rare and interesting biopsy cases at any time.
All equipment undergoes regular maintenance and internal quality control in accordance with good laboratory practice and international accreditation standards. Recently, we were visited by a professor from Paris, who was genuinely impressed by our laboratory’s equipment and structure. Recognition at such a high level is highly motivating for us.
4. Which hospital departments do you work with most actively?
We receive materials from all hospital departments, with particularly active collaboration with oncology, gynecology, obstetrics, and surgery. The cooperation is two-way — clinicians provide us with complete clinical information, while we ensure timely morphological verification and substrate for further precision medical studies.
Together with the Medical Genetics Laboratory, we provide patients with integrated diagnoses that are crucial for therapy personalization — ensuring each patient receives the most effective treatment at the right time. We also discuss our analyses with colleagues from the hospital’s Virology and Microbiology Laboratories.
In recent years, we have introduced expanded immunohistochemical diagnostic panels, enabling highly detailed diagnoses without requiring patients to seek additional testing elsewhere.
Our laboratory offers a broad range of immunohistochemical markers, including some available only in a few laboratories across Eastern Europe, such as INI1, Myogenin, PAX2, and PTEN.
Together with specialists in Medical Genetics, we are actively developing molecular techniques for identifying predictive and prognostic biomarkers — essential in decisions regarding targeted and immunotherapy for oncology patients.
We provide rapid molecular classification of endometrial cancer, which stratifies patients into prognostic groups and guides decisions regarding radiotherapy, chemotherapy, and emerging immunotherapy approaches.
We also perform molecular-genetic studies such as FISH, PCR, and NGS for breast cancer, glial brain tumors, and colorectal cancer.
The implementation of digital pathology methods is forthcoming, enabling remote consultations with specialists from reference centers. We are also preparing to establish a consultancy agreement with a distinguished professor in neonatal and placental pathology from the United States.
6. What should patients know about histological and cytological test results? Why can they not be completed “within a day”?
The histological examination process includes several stages: fixation (6–72 hours), dehydration, paraffin embedding, preparation of ultra-thin sections (typically 3.5–5 µm), and staining using standard hematoxylin and eosin. Each stage requires time and precision to avoid artifacts and ensure diagnostic reliability. Therefore, a turnaround time of several days is both necessary and justified — result quality is directly linked to the time dedicated to each step.
A crucial part is also the microscopic analysis, which may require additional histochemical, immunohistochemical, or molecular-genetic studies. The era when histological diagnoses simply stated “tumor/no tumor” is over. Today, our diagnoses are integrated, supported by imaging studies, properly processed tissue samples, and multiple advanced tests. This comprehensive approach requires one to two weeks to establish an integrated diagnosis that provides oncologists with the necessary basis for the most effective therapeutic strategy.
7. Is the workload in this field increasing?
Each year, we observe a clear rise in the number of examinations — including cytology smears, biopsies, and second-opinion cases. This reflects both the trust of colleagues and patients, and the growing need for highly specialized morphological diagnostics in clinical practice.
We examine dozens of cytological materials daily, which provide crucial guidance for patient management. Biopsy materials from surgical interventions performed in the hospital are also reviewed regularly, while second-opinion materials arrive daily.
The number of precision molecular-genetic tests is also increasing. Any patient seeking professional care, a detailed diagnosis, and expert guidance is welcome to turn to us.
Our specialists undergo annual advanced training in gynecological, gastrointestinal, breast, and neuropathology, among other areas.
8. Are there opportunities for young professionals to specialize at Nadezhda Hospital?
The laboratory is an accredited training base for residents in General and Clinical Pathology and Cytopathology. Future specialists will have access to diverse cases across pathology fields, including biopsy and cytology materials from the hospital and second-opinion cases.
We also maintain an extensive archive of pathological images and presentations showcased at scientific forums in Bulgaria and abroad.
I believe investing in young specialists is a key factor in advancing the specialty in our country. We already have candidates interested in specializing with us, and one future colleague has demonstrated both commitment and talent for this demanding field.
Pathology was once underestimated and placed in the background, but this is no longer the case — at least not in major pathology laboratories such as ours.
9. Beyond clinical work, do you also have opportunities for scientific research at Nadezhda Hospital?
Yes, we actively participate in scientific projects made possible through collaboration with the hospital’s medical research department. We are proud of completed projects in areas such as endometriosis, adenomyosis, COVID-19 morphology, cortical developmental malformations, and chronic endometritis. We are also part of international collaborations that provide access to new diagnostic technologies and methodologies that may support future therapeutic strategies for oncology patients.
I am particularly excited about my current work with distinguished researchers from Paris and our neurosurgeons on cases involving bone metastases. I cannot share further details, as our results have not yet been published, but I hope they will receive deserved recognition from the scientific community.
10. What is your personal motivation for working at Nadezhda Hospital?
My motivation comes from a professional environment that combines high standards of medical practice with a humane approach to patient care.
Nadezhda Hospital places the patient at the center of the diagnostic and therapeutic process, and for a pathologist this means being part of real clinical dynamics and contributing to the ultimate goal — a detailed diagnosis that supports effective, personalized treatment.
Thanks to the support of the hospital’s leadership, we have the opportunity to implement the latest diagnostic methods in pathology, enriching us as clinical pathologists and securing our place in Bulgarian pathomorphological practice and science.
