Aim: To analyze age and sex distribution of the cardiac tumors, the most common clinical symptoms, POSTER SESIJA 70 MATERIA MEDICA • Vol. 34 • Issue 1, suplement 1 • april 2018. pathohistological types, tumor localization and compare the echocardiographic with the pathohistological size of the tumor. Introduction: The incidence of primary cardiac tumors are very rare and amounts to about 0.02%. Incidence of secondary cardiac tumors are significantly higher. Primary malignant cardiac tumors are very rare and represent to the rarest tumors in the human organism. Materials and Methods: The study covered 49 patients who were operated in the period from 2008 to 2017. Patients data are obtained from the history of the disease, the information system and pathohistological findings. Results: The average age of the patients is 53.9 years. The most common symptoms were light fatigue, heart palpitations, vertigo, dizziness, dyspnea, exhaustion, cough and stenocardia. The most commonly diagnosed are myxomas (67.3%), papillary fibroelastomas 28.6%, cavernous hemangiomas 4.1%, and metastatic tumors 2.04%. The most common tumor localization is in the left atrium 63.3%, aortic cusps 16.3%, right atrium 8.2%, mitral valve 8.2%, left ventricle 2.04% and interventricular septum 2.04%. The difference in mean echocardiographic tumor size and tumor size after surgical extirpation was not statistically significant (p = 0.706). Conclusion: Although, cardiac tumors are rare, they have a large clinical importance, primarily because of the potential for severe complications such as embolization of the arteries of the brain with the development of cerebral infarction and even the appearance of sudden death. However, timely diagnosis and surgical removal of tumors lead to patient curing in most cases.

Aim: Purpose of this report is to present metastasis of lymph nodes melanoma with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) as an example of collision tumor of an uncommon synchronic occurrence in the lymph node. Introduction: Synchronic, composite tumors are rare and their simultaneous and synchronic occurence within the same tissue/organ is even more rare. CLL/SLL is an indolent, clonal disease of mature B-lymphocytes which occurs mostly with adults. After the treatment with chemotherapeutic agents the occurence of the secondary malignancies (melanoma,squamous-cell carcinoma). Material and Methods: We present a 77 year old male who, after right sided nephrectomy caused by clear-cell carcinoma was diagnosed with CLL/SLL with bone marrow and lymph node infiltration. After three years and chemotherapy, skin changes were excised which histomorphologically resembles melanoma. After the immunotherapy for melanoma, the enlarged lymph nodes were extripated from the neck and histomorphologically and immunohistochemically treated. Results: Histomorphologically, a diffused infiltration of small B-lymphocytes was found in the lymph node, with round nuclei, condensed chromatin, inconspicuous nucleoli, scant cytoplasm unique immunophenotype: CD20 ,PAX-5 ,CD5 ,CD23 ,Cyclin D1-,CD3-. A part of lymph node was infiltrated by epitheloid cells with immunohistochemic profile: S-100 ,Melan A ,HMB-45 . Histomorphological and immunohistochemical CLL/SLL with melanoma infiltration as an example of a collision tumor was proved. Conclusion: Lymphoproliferative neoplasms including CLL/SLL represent an risk of synchronous, metachronous development of secondary malignancies including melanoma itself and they can uncommonly present themselves as synchronic collision tumors within the same organ.

Aim: We present the case of a patient aged 68 years who died of chronic heart failure caused by untreated cardiac sarcoidosis (CS). Introduction: Sarcoidosis is a multisystem disorder of unknown etiology, characterized by granulomatous infiltration and the development of noncaseating granulomas in many organ systems. Although the lungs, eyes, and skin are most commonly affected, virtually any body organ can be involved. Clinical evidence of CS is seen only in 5% of patients and the disease may present with tachyarrhythmias, conduction disturbance, heart failure, or sudden cardiac death. Case report: The patient was received in the hospital due to symptoms and signs of global cardiac decompensation with difficulties in the form of dyspnea, orthopnea, and edematous legs. Echocardiographic, cardiac cavities are very dilated with globally reduced systolic function, severe mitral regurgitation and ejection fraction about 20%. Very soon after receiving the patient is died. At autopsy, the heart was dilated, primarily the left ventricle. Histologically, the myocardium was infiltrated by numerous granulomas built of lymphocytes, epitheloid cells, and giant multicellular cells of the Langhans type. As a consequence of severe chronic heart failure, the lungs were edematous with both sides of massive plural effusions. The coronary arteries were non-significantly stenosed. Conclusion: Early diagnosis and treatment can prevent significant morbidity and mortality in patients with CS. It is very important that patients with CS in the early stage of the disease be treated with corticosteroids.

Aim: Immunohistochemistry findings along with clinical features, are significantly important in differentiating the Extrapleural SFT in the neck, from other well-circumscribed mesenchymal neoplasms at this locations. Introduction: We present a rare case of a Extrapleural SFT in a 57 years old man in the neck, without significant past medical history. Material and Methods: The patient had a painless slow growing tumor, in right sight of the neck, diagnosed with physical examination. Total excision with local anesthesia was done, without previously biopsy of the tumor and other clinical investigations. Standard procedures for histology and immunohistochemical stains were done. Results: Tumor was well circumscribed, encapsulated measuring 5,5x4x4 cm. On section, the cut surface had a multinodular, whitish and firm appearance. On microscopic examination tumor was composed of alternating hypocellular and hypercellular areas separated from each other by thick bands of collagen and branching haemangiopericitoma like vessels. The tumor cells were round to spindle-shaped with little cytoplasm, indistinct borders, dispersed chromatin within vesicular nuclei. Area of myxoid change and subcapsular focus of hemorrhage was present, and 2 mitoses/10 HPF were found. Immunohistochemistry revealed diffuse positivity for CD34, Vimentin and BCL2, focal positivity for CD99, S100, SMA, and negativity for CKWS and EMA. Ki67 showed low proliferating index 3-5%. Conclusion: Although most cases of SFT are benign, there is no strict correlation between morphology and behavior, so patients with extrapleural solitary fibrous tumor have need of long-term post-resection follow-up. Further studies are needed to determine the optimal management of these neoplasms.

Aim: We present an illustrative autopsy case of thrombosed giant bilateral vertebral artery aneurysms. Introduction: A 61-year-old male died at Department of Infective disease with a clinical diagnosis for bilateral bronchopneumonia, cerebral aneurism, fibro muscular dysplasia, CVI, HTA, chronic CMP, cardiac arrest. Material and Methods: Standard autopsy technic with neuropathology brain dissection and standard procedure of paraffin embedded section routinely stained with HE was performed. Results: Gross examination of the brain at the autopsy showed saccular giant bilateral vertebral artery aneurysms that measured 58 mm on the right and 40 mm on the left artery. They were tumor-like and compressed the medulla and pons. Both were thrombosed. The right was ruptured with subacute subarachnoid bleeding. Sections of the cerebral vessels exhibited minimal atherosclerotic plaques, with mild stenosis (focally up to 10%) of the left internal carotid artery. We found mild dilatation on ventricles and minimal cortical atrophy of the brain. During the microscopic examination angiodysplasia with abnormally dilated blood vessels on visceral organs, predominantly on brain and heart was detected. The cause of death was central type of cardiopulmonary insufficiency with pulmonary edema. Conclusion: We presented an extremely rare case with bilateral giant vertebral aneurysms. Giant cerebral aneurysms are ones that measure >25 mm in greatest dimension and account for ~5% of all intracranial aneurysms. They occur in the 5th-7th decades and are more common in females. Vertebral artery aneurysms constitute 0.5 to 3% of intracranial aneurysms and 20% of posterior circulation aneurysms.

To present pathological processes of the TG with histological detection of granulomas, analysis of morphological forms of granulomas, and their diagnostic significance. This paper is based on literature review and insight into the archival materials of the Institute of Pathology and Forensic Medicine of the Military Medical Academy.The presence of granulomas in the thyroid gland (TG) includes specific pathological processes such as subacute thyroiditis (SAT) and palpation thyroiditis (PT). The clinical manifestations of the granulomas may be accompanied by symmetrical or asymmetrical enlargement and palpatory pain in the gland, which requires further clinical examination. Granulomas in the TG can be associated with various benign and malignant processes. There are two large groups of granulomas: foreign-body giant cell granulomas (FBG) and immune granulomas (IGR). FBG are histiocytic reactions to chemically inert, exogenous or endogenous materials. Etiologically, IGRs arise in the framework of infectious, autoimmune, toxic, drug-induced or pathological processes of unknown etiology. According to the presence of necrosis IGRs can be further divided as necrotizing or non-necrotizing type. TG granulomas of the infectious, autoimmune or inflammatory nature of the unknown etiology are extremely rare. 1. Granulomas in specific pathological processes of the TG Subacute (de Quervain’s) thyroiditis or granulomatous thyroiditis is an inflammatory process that is clinically presented as enlarged and painful TG. In most cases, the result is a complete recovery of the TG function. Permanent hypothyroidism is found in about 5% of patients. SAT is usually preceded by upper respiratory tract infection. The disease is etiologically related to viral infections, genetic predisposition and the use of immuno therapy. Macroscopically, TG is usually symmetrically enlarged, but there are also localized forms with nodular morphology, which imitate neoplastic lesions. The microscopic characteristic is the presence of multifocal and diffusely distributed folliculocentric granulomas. They are found in different phases and consist of epitheloid histiocytes, lymphocytes, plasma cells, neutrophils, and multinuclear giant cells (MGC). At the center of the granuloma, the colloid is reduced or absent. In later phases, fibrosis can develop perifollicularly. In terms of differential diagnosis (DDG), it is important to differentiate SAT from other granulomatous inflammations. Palpation thyroiditis (Multifocal granulomatous folliculitis) is the most common pathological process in TG with microscopic detection of granulomas. It is an incidental microscopic finding involving individual or minor follicular groups. Changes arise as a result of mechanical microtrauma after the palpation of the TG. Microscopic changes are characterized by damage to the follicles with interfollicular APSTRAKTI 73 MATERIA MEDICA • Vol. 34 • Issue 1, suplement 1 • april 2018. accumulation mainly of histiocytes in the presence of lymphocytes, plasma cells and MGCs. In the DDG of PT, the following conditions must be considered: SAT, primary and secondary microscopic foci of papillary microcarcinoma, C-cell hyperplasia, and focal forms of Langerhans histiocytosis. 2. Foreign-body giant cell granuloma is frequent incidental microscopic finding in TG. It arises as a reaction to the accumulation of endogenous substances in the areas of spontaneous or degenerations induces by fine-needle aspiration biopsy (FNAB). The most common forms of FBGs on endogenous material are cholesterol granulomas. These FBGs are composed of MGCs, foamy histiocytes, and hemosiderophages arranged around crystal deposits. Depending on how old the lesion is, there may be a focal necrosis, a different degree of fibrosis, extracellular deposits of hemosiderin, and other inflammatory cells. The presence of FBGs and histiocytic aggregates is not only important in the preoperative cytological diagnostics, but also in the post-operative pathohistological analysis of TG nodules. Large nuclei of histiocytes with hypochromasia, nuclear membrane irregularities and the presence of MGC can imitate the cytological features of papillary thyroid carcinoma (PTC). Exogenous biomaterials are rarely cause of FBGs in TG. After thyroidectomy, in cases of diagnosed TG malignancies, the presence of suture FBGs in thyroid bed imitates recurrence or the rest of malignancy and is the cause of repeated surgeries. 3. Necrotizing granulomas (NGR) in TG Granulomas with necrosis may be of infectious and noninfectious etiology. Tuberculosis is the most common cause of NGR in TG. Tuberculosis in TG can be presented as a solitary nodal lesion, diffuse microlesions, nodular goiter, and rarely as an abscess or a chronic skin sinus. As a infectious cause of NGR in TG, sporadically reported cases have been caused by histoplasmosis, coccidioidomycosis and nocardiosis. Rare non-infectious NGR in TG or in the TG bed, of autoimmune etiologies, have been described as part of Wegener’s granulomatosis and rheumatoid arthritis. Post-operative necrotizing granulomas also represent NGR of non-infectious cause. Microscopically, there is a morphology that matches post biopsy granulomas in other organs (prostate, urinary bladder). 4. Non-necrotizing granulomas (NNGR) in TG Sarcoidosis is a multi-systemic chronic granulomatous inflammation of unknown etiology. Thyroid is rarely affected by sarcoidosis. Macroscopically, the gland is diffusely or nodularly enlarged or reduced in volume. Interstitially localized NNGR represent a typical histological presentation. Sarcoidosis of TG should be distinguished from the sarcoid-like stromal reactions of PTC in the gland or regional lymph nodes. In these cases, it is necessary to clinically exclude the systemic disease. 5. Granulomas and histiocytic reactions in neoplastic processes of TG Apart from the described FBGs, PT and sarcoid-like reactions, in epithelial tumors of the TG histiocytic aggregates (not granulomas) may also be seen as secondary changes after FNAB. Interfollicular/ intraluminal presence of MGCs with or without the presence of histiocytes and granuloma-like morphology represents a characteristic finding in PTC. The cytological and histological detection of MGCs is one of the diagnostic criteria for PTC. Their presence in tumors may be due to a reaction to an altered colloid produced by PTC or as a non-specific immune response to due tumor cells. Conclusion: Granulomas in the TG are not rare. Knowing the morphology of granulomas, pathological processes and the circumstances in which they occur is significant in DDG of primary tumors of the TG, their recurrence and metastases in the cervical lymph nodes. The diagnosis of granulomatous inflammation in TG can be based on the histological characteristics of granulomas in correlation with clinical and laboratory findings.

Ova mala kliničko-patološka kategorija tumora se odlikuje nepredvidljivošću kliničkog toka i/ili ishoda bolesti, a tome u prilog često govore i patohistološka obeležja tumora koja pružaju samo neke odlike maligniteta, sugerišu mogući maligni potencijal ili pokazuju odlike između benignih i malignih proliferacija1. Boljim definisanjem dijagnostičkih kriterijuma danas su ovi tumori smanjeni na manje od 5% svih tumora u GI i HBP sistemima, a njihov maligni potencijal se često posredno izražava kao proliferativni, recidivni ili metastatski potencijal2,3. Najveći broj njih odnosi se na dobro diferentovane neuroendokrine tumore (NET), gastrointestinalne stromalne tumore (GIST) i mucinozne cistične neoplazije (MCN). Od epitelnih neoplazija nejasnog malignog potencijala u digestivnoj cevi se posebno izdvajaju mucinozne neoplazije apendiksa i cekuma (do 0,2% tumora GIT) često praćene rupturom i peritonealnim pseudomiksomom kao tzv. „diseminovana peritonealna mucinoza“4. One se odlikuju „cistadenomskom“ morfologijom, ponekad kompleksne acinusne i mikrocistične organizacije sa displastičnim epitelom i mucinoznom (pseudo)invazijom zida, ali bez invazivnosti epitelnih elemenata5. Slična histološka obeležja vide se u kod mucinoznih cističnih neoplazija (MCN) u biliopankreatičnom traktu i jetri, gde se displastične epitelne promene duktusa pankreasa (analogne pankreasnoj intraepitelnoj neoplaziji PanIN I-III), i bilijarnih duktusa (analogne bilijarnoj intraepitelnoj neoplaziji BilIN I-III) u perifernim zonama razgranavanja moraju jasno razlikovati od rane invazije, tj. od adenokarcinoma6. Kad su u pitanju adenomatozni polipi sa pseudoinvazijom u digestivnom traktu, oni se moraju razlikovati od pravih „malignih polipa“ tj. adenomatoznih polipa sa ranom invazijom koji pokazuju disekciju stromalnih elemenata mukoze i submukoze i izazivaju dezmoplastičnu reakciju. Pseudoinvazija se odlikuje odsustvom infiltrativnog tipa rasta, dezmoplazije, uočavanjem strome (lamine proprije) oko prolabiranih glandularnih struktura, hemoragijom, hemosiderofagijom, a nekada i invertnim rastom, bilo pulzionim ili limfovaskularnim, kao i stvaranjem limfoglandularnih kompleksa sa fokalnim limfoidnim agregatima7. Kada su u pitanju dobro diferentovani NET, danas se pored klasične i imunohistohemijske dijagnostike obavezno moraju odrediti i korelirati mitotski indeks (MI) izražen na 10 polja velikog mikroskopskog uveličanja, ali određen na najmanje 50 polja, kao i procentualni proliferativni Ki-67 indeks određen u području najveće aktivnosti na najmanje 500 ćelija. Na taj način određuje se stepen maligniteta NET koji po novoj klasifikaciji iz 2017. godine koji pored NET-G1 i NET-G2 podrazumeva i novouvedeni dobro diferentovani NET visokog stepena (NET-G3) za tumore sa MI preko 20 /10HPF i Ki-67 indeks preko 20%, ali koji se moraju razlikovati od slabo diferentovanih neuroendokrinih karcinoma (NEC) istih ili viših vrednosti ovih parametara8. Značajna je i grupa visceralnih mezenhimalnih tumora nejasnog malignog potencijala koji se pojavljuju u digestivnom sistemu, posebno za GIST kao najčešći od njih i koji čini oko 2% klinički značajnih tumora u abdomenu. Danas su jasno definisani AFIP kriterijumi malignog potencijala (Miettinen, 2005) i NIH kriterijumi metastaskog potencijala (Fletcher, 2002) koji čine i sastavni deo aktuelnih TNM klasifikacija. Oni uključuju obavezne podatke o preciznoj lokalizaciji i veličini tumora i mitotskom indeksu izraženom na 50 polja velikog mikroskopskog uveličanja9. Na osnovu toga se prepostavljaju stepeni rizika malignog toka bolesti i uključivanja adjuvantnih terapijskih protokola, dok je za lečenje metastatske i/ili neresektabilne bolesti neophodno određivanje mutacionog statusa KIT, PDGFRA, SDHA i SDHB gena. Takođe je značajno prepoznavanje i nalčin dijagnostike inflamatornog miofibroblastnog tumora (IMT) koji najčešće zahvata adolescente i mlade ženske odrasle osobe (75% intra-abdominalno i ponekad multinodularno), a histološki se odlikuje karakterističnom mešavinom inflamatornih (posebno limfoplazmocitnih i histiocitnih) i stromalnih (posebno miofibroblastnih) elemenata10. Karakteristična nuklearna imunoreaktivnost za ALK-1 protein se vidi samo u oko 50% slučajeva. Ovaj tip tumora ima nepredvidiv tok, ali se recidivi (29%) i metastaze (4%) češće javljaju kod epiteloidnih hipercelularnih i mitotski aktivnijih tumora sa pojavom nuklearne atipije stromalnih ćelija11. Hepato-biliopankreatični tumori nejasnog malignog potencijala osim pomenutih MCN podrazumevaju i intraduktalne papilarne mucinozne neoplazme (IPMN) sa teškom epitelnom displazijom (analogne BilIN III, PanIN III) ali bez pridružene mikroinvazije ili jasnih adenokarcinoma12. Takođe, hepatomi nejasnog malignog potencijala su hepatoidni tumori koji odgovaraju hepatocelularnim adenomima (HCA) s ati- 75 MATERIA MEDICA • Vol. 34 • Issue 1, suplement 1 • april 2018. pijom neoplastičnih ćelija i koji ne ispunjavaju sve ostale parametre maligniteta (elementi invazivnosti, trabekularna dezorganizacija i povećanje broja gredica, evidentna mitotska aktivnost) a po pravilu su “beta-katenin aktivišući tip” HCA koji se imunohistohemijski može dokazati i koji pokazuje visok stepen maligne transformacije13. Usled toga je neophodno ekstezivno uzorkovanje velikih HCA tumora da se ne bi previdela fokalna maligna alteracija. U jetri se retko može videti i epiteloidni hemangioendoteliom (EHE), nepredvidivog kliničkog toka, koji se često pogrešno interpretira kao (adeno)karcinom. Po pravilu se javlja kod osoba srednjeg životnog doba, kao multipla nodularna promena (80%) i javlja se s ekstrahepatičnim širenjem u 50% slučajeva. Neophodno je da se kod mladih jasno razlikuje od infantilnog hemangioendotelioma. Mikroskopski se odlikuje zonalnošću sa centralnom miksohondroidnom i sklerotičnom promenom u kojoj se vide dendritične tumorske ćelije, dok se periferno uočavaju delom obliterisani a delom prošireni sinusoidi sa papilarnim projekcijama atipičnog endotela14. Često se u tumorskim ćelijama vide intracitoplazmatske vakuole koje mogu sadržati eritrocite. Mora se razlikovati od dobro diferentovanog angiosarkoma visokom celularnošću i jačom atipijom, što je povezano i sa malignom alteracijom EHE. Pankreasna solidno-pseudopapilarna neoplazija se odlikuje češćim benignim kliničkim tokom nego recidivima i veoma retkim metastaziranjem. Opisala ju je Virginia Franz (1959) kao pedijatrijski benigni tumor, ali se danas izdvaja boljom mikroskopskom karakterizacijom kod adolescenata i mladih (10-45 god.). Obilno se javlja u distalnom pankreasu, promera od 3-15 cm kao jasno ograničen, lobuliran, hemoragičan tumor. Histološki ga odlikuju papilarnost, pseudorozete, holegranulomi i fokalna hijalinizacija15. Maligni potencijal i rizik metastaziranja se povezuju sa hipercelularnošću, atipijom i izraženijom mitotskom aktivnošću. 

Aim: Reporting a patient with unusual metastatic site of invasive lobular breast cancer (ILC) as initial presentation of the disease. Introduction: Due to specific growth pattern, ILC rarely forms an apparent tumor, which makes diagnosis very challenging at early stage. ILC is also known for unconventional metastatic spread, with deposits being discovered prior to the primary tumor in 3-10% of cases. Case report: While evaluating renal function in 51-year old female patient hospitalised at the Urology Clinic (Clinical centre of Montenegro), static scintigraphy revealed left kidney functional capacity of 7-8%. Nephrectomy was indicated. Kidney, 11x6x4cm in size, with slightly reduced, paler parenchyma, firmly attached fatty capsule and pyelocaliceal system and ureter of regular gross appearence, was delivered to the Centre for Pathology. Analysis of H E sections revealed chronic pyelonephritis. In a few sections taken from urether, pyelon and subcapsular parts of parenchyma, infiltrates of small, cuboid, atipical cells, mostly arranged in one-cell-thick files, were noted. Immunohistochemistry reveiled strong pozitivity for EMA, CK(ae1/ae3), CK7, estrogen and mammaglobin, with Ki67<10%. A few cells were progesteron positive, while vimentin, CK20 and neuroendocrine markers were negative. ILC metastasis was suspected. ILC, with axillary lymph POSTER SESIJA 66 MATERIA MEDICA • Vol. 34 • Issue 1, suplement 1 • april 2018. node involvement, was confirmed later, although there was no macroscopically apparent tumor in the breast. Tumor cells were estrogen and progesterone positive, HER2 negative, with Ki67 of 3%. Conclusion: While assessing metastatic deposits in unconventional sites in women, primary ILC should be considered. Special diagnostic algorhytm is required for efficient initial detection of the primary tumor.

Aim: We present the case of a woman with endobronchial pulmonary synovial sarcoma. Introduction: Primary pulmonary synovial sarcoma is an extremely rare tumor that has the same histomorphological characteristics and chromosomal translocations as the synovial sarcoma of soft tissue origin. Material and Methods: A woman aged 58 years, the smoker, without the current symptoms of the disease, came to our institution because of the nodus that was seen on the CT chest. The polip (26 mm) was located in the lumen of the lower right lobar bronchus. The mediastinal and hilar lymph nodes were not increased. The radiological examination was done as part of a routine control after the meningeoma surgery three years ago. Right lower lobectomy and resection of regional lymph nodes were performed. Results: By a macroscopic examination, in the lumen of the bronchus for the lower right lobes, a clearly limited, nonencapsulated, grayish-white node of 2.6 x 2.6 x 1 cm was found. Histologically, the tumor was showed interweaving fascicular uniform spindle cell with ovoid, pale staining nuclei, and inconspicuous nucleoli, scant cytoplasm and the cell borders indistinct. Immunohistochemical tumor cells were positive for CD99, bcl2 and vimentin. Surgical margins and regional lymph nodes were not affected. A detailed clinical and radiological examination confirmed the primary lung origin of the diagnosed synovial sarcoma. A year after surgery the patient feels good. Conclusion: Morphological and immunohistochemical analysis with detailed clinical and radiological examination confirms the primary lung origin of synovial sarcoma

Aim: To evaluate surgical lung biopsies in patients with a clinically and radiologically set diagnosis of ILD. Introduction: Interstitial lung diseases (ILDs) are a group of lung diseases affecting the lung interstitium. These entities share similar clinical and radiological features and are distinguished primarily by the histopathologic patterns on surgical lung biopsy. Material and Methods: The study included 30 patients with a surgical lung biopsy performed in 10-year period at the Institute for Pulmonary Diseases of Vojvodina in Sremska Kamenica. Standard H E stain, special stains for conective tissue and smooth muscle, as well as immunohistochemistry in some cases were used. The patient’s age, sex, clinical symptoms, surgical biopsy type and histological findings were analyzed. Results: Of the 30 patients who underwent surgical lung biopsy, an open lung biopsy according to Claassen was performed in 14 patients, in 12 biopsies biopsy according to Maassen was obtained, while in 4 patients material for histopathological analysis was taken by VATS (Video - Assisted Thoracoscopic Surgery). The most common biopsy site was upper lobe in 16 cases, then lingula in 10, middle lobe in 2, and lower lobe and lung base in 1 patient. By histopathological analysis, diagnosis of UIP in 8, PLCH in 7, sarcoidosis in 6, hypersensitivity pneumonitis in 3, NSIP in 2, LAM, LIP, DIP and ACIF in 1 patient. Conclusion: Diagnosis of ILD is based on history, physical examination, high-resolution CT imaging, pulmonary function tests, and lung biopsy which presents golden standard in diagnostic approach.