Pearl Formation Research Articles

ORAL SQUAMOUS CELL CARCINOMA ARISING FROM A MAXILLARY RESIDUAL ODONTOGENIC CYST: A CASE REPORT

A 65-year-old male patient, drinker, ex-smoker, was referred to a stomatology clinic for evaluation of a lesion located in the upper alveolar ridge that had appeared 15 days previously. Intraoral examination revealed a reddish sessile nodule with yellowish-white spots. A swelling of hardened consistency in the hard palate was also observed. Radiographic examination and computed tomography showed an expansive bone lesion in the right maxilla and a disruption in the cortical lower margin, connecting the bone lesion to oral mucosal nodule. A biopsy of the nodular lesion was performed and histopathologic examination indicated squamous cell carcinoma (SCC). The patient underwent partial maxillectomy and surgical specimen showed cystic epithelium with malignant transformation, numerous keratin pearl formation, and atypical mitosis. Final diagnosis was a primary intraosseous SCC arising in a residual odontogenic cyst. After 2-year follow-up, the patient has been in good general health without signs of recurrence.

Functional Prioritization and Hydrogel Regulation Phenomena Created by a Combinatorial Pearl-Associated Two-Protein Biomineralization Model System.

In the nacre or aragonitic layer of an oyster pearl, there exists a 12-member proteome that regulates both the early stages of nucleation and nanoscale-to-mesoscale assembly of nacre tablets and calcitic crystals from mineral nanoparticle precursors. Several approaches to understanding protein-associated mechanisms of pearl nacre formation have been developed, yet we still lack insight into how protein ensembles or proteomes manage nucleation and crystal growth. To provide additional insights, we have created a proportionally defined combinatorial model consisting of two pearl nacre-associated proteins, PFMG1 and PFMG2 (shell oyster pearl nacre, Pinctada fucata) whose individual in vitro mineralization functionalities are distinct from one another. Using scanning electron microscopy, atomic force microscopy, Ca(II) potentiometric titrations, and quartz crystal microbalance with dissipation monitoring quantitative analyses, we find that at 1:1 molar ratios, rPFMG2 and rPFMG1 co-aggregate in specific molecular ratios to form hybrid hydrogels that affect both the early and later stages of in vitro calcium carbonate nucleation. Within these hybrid hydrogels, rPFMG2 plays a role in defining protein co-aggregation and hydrogel dimension, whereas rPFMG1 defines participation in nonclassical nucleation processes; both proteins exhibit synergy with regard to surface and subsurface modifications to existing crystals. The interactions between both proteins are enhanced by Ca(II) ions and may involve Ca(II)-induced conformational events within the EF-hand rPFMG1 protein, as well as putative interactions between the EF-hand domain of rPFMG1 and the calponin-like domain of rPFMG2. Thus, the pearl-associated PFMG1 and PFMG2 proteins interact and exhibit mineralization functionalities in specific ways, which may be relevant for pearl formation.

Donor and recipient contribution to phenotypic traits and the expression of biomineralisation genes in the pearl oyster model Pinctada margaritifera

Grafting associates two distinct genotypes, each of which maintains its own genetic identity throughout the life of the grafted organism. Grafting technology is well documented in the plant kingdom, but much less so in animals. The pearl oyster, Pinctada margaritifera, produces valuable pearls as a result of the biomineralisation process of a mantle graft from a donor inserted together with a nucleus into the gonad of a recipient oyster. To explore the respective roles of donor and recipient in pearl formation, a uniform experimental graft was designed using donor and recipient oysters monitored for their growth traits. At the same time, phenotypic parameters corresponding to pearl size and quality traits were recorded. Phenotypic interaction analysis demonstrated: 1) a positive correlation between recipient shell biometric parameters and pearl size, 2) an individual donor effect on cultured pearl quality traits. Furthermore, the expressions of biomineralisation biomarkers encoding proteins in the aragonite or prismatic layer showed: 1) higher gene expression levels of aragonite-related genes in the large donor phenotype in the graft tissue, and 2) correlation of gene expression in the pearl sac tissue with pearl quality traits and recipient biometric parameters. These results emphasize that pearl size is mainly driven by the recipient and that pearl quality traits are mainly driven by the donor.

Influence of preoperative food and temperature conditions on pearl biogenesis in Pinctada margaritifera

Trophic conditions and water temperature strongly influence bivalve physiological processes and metabolism. In black-lip pearl oyster Pinctada margaritifera, these parameters have been shown to affect shell biomineralization. The present study investigated the effect of preoperative food level (i.e., microalgal concentration) and temperature on pearl biomineralization. Donor and recipient oysters were conditioned at different levels of food and temperature during the preoperative phase to evaluate the influence of these factors on 1) pearl retention rate (grafting success), 2) expression of genes involved in biomineralization in the mantle and pearl sac and 3) pearl quality traits. Our study confirmed the influence of both microalgal concentration and temperature on shell growth. Food level of donor oysters was decisive for pearl biomineralization, with donors that had been fed at a high microalgal concentration producing pearl sacs with significantly higher biomineralization capabilities and faster nacre establishment during early stages of pearl formation. However, food level showed no effects on quality traits of the pearls harvested 12months postgrafting, while preoperative temperature only influenced the relative expression of two genes in pearl sacs at 12months postgrafting. No significant effects of the preoperative conditioning of recipient oysters were detected in either experiment considering gene expression measurements and pearl quality traits. However, mortality was significantly lower in grafted recipient oysters fed at an intermediate trophic level. Finally, pearl weight was shown to be positively correlated with recipient oyster growth.

Physiological response to relaxation as pre-operative therapy to pearl formation in the winged pearl oyster Pteria sterna

This study expands on the criteria for selecting relaxants used in commercial production of pearls, based on the hypothesis that relaxation, before acting at a cellular level, is a stressor that triggers a battery of physiological responses. Four relaxants at two concentrations each were tested for survival, relaxation and recovery, incidence of spawning, condition index, glycogen index, mucopolysaccharide index, and lipofuscin index in the winged pearl oyster Pteria sterna. The relaxants are: propylene phenoxetol (1.5 and 2.5mLL−1), benzocaine (0.15 and 0.25gL−1), magnesium chloride (15 and 30gL−1), and clove oil (0.25 and 0.50mLL−1). Benzocaine (0.25gL−1) and propylene phenoxetol (2.5mLL−1) promoted >85% relaxation in <45min, but induced the oysters to spontaneously spawn. The poorest efficiency for relaxation and recovery of oysters occurred with magnesium chloride at both concentrations. In all treatments, the glycogen index decreased in adductor muscle and increased in the gonad >50% with benzocaine, suggesting mobilization of energy reserves likely tied to spawning. In the digestive gland, the glycogen index also decreased by 30% with clove oil (0.5mLL−1), but the response with this relaxant is attributed to oxidative stress and use of glycogen reserves to cover other physiological needs, such as immune protection. Relaxing with benzocaine caused a significant accumulation of lipofuscins in the gills and mantle, again as possible indicator of oxidative stress. Based on these results, we recommend using propylene phenoxetol at 1.5mLL−1 for maximum relaxation with minimum deleterious effects in P. sterna.

Vulvar Squamous Cell Carcinoma In A Horse : A Case Report

Formalin fixed tumor mass from vulva of mare was received from TVCC, PGIVAS, Akola for histopathological examination and diagnosis. Clinical examination findings reported were large ulcerated, neoplastic mass located at the unpigmented areas on the mucocutaneous junction of the vulva. Histopathologically, the ulcerated growth showed irregular cords of neoplastic squamous epithelial cells surrounded by connective tissue stroma. The tumor showed formation of keratin pearls in the centre of cords and presence of few mitotic figures. The neoplastic squamous cells showed large hyperchromatic nuclei. On the basis of histopathological examination, the present case was diagnosed as vulvar squamous cell carcinoma.

Formation and Quality of Pearls

Formation and Quality of Pearls

Characterization of transcriptome and identification of biomineralization genes in winged pearl oyster (Pteria penguin) mantle tissue

The winged pearl oyster Pteria penguin is a commercially important marine pearl oyster species, with pearls that are quite different from those of other pearl oysters. Among such species, mantle tissue is the main organ responsible for shell and pearl formation, a biomineralization process that is regulated by a series of genes, most of which remain unknown. In this study, we sequenced and characterized the transcriptome of P. penguin mantle tissue using the HiSeq 2000 sequencing platform. A total of 93,204 unique transcripts were assembled from 51,580,076 quality reads, with a mean length of 608bp, and 40,974 unigenes were annotated. The sequence data enabled the identification of 79,702 potential single nucleotide polymorphism loci and 4345 putative simple sequence repeat loci. A total of 71 unique transcripts were identified homologous to known biomineralization genes, including mantle gene, nacrein, pearlin, pif, chitinase, and shematrin, of which only 3 were previously reported in P. penguin. qPCR analysis indicated that 10 randomly selected biomineralization genes were much more highly expressed in mantle tissue than in the other tissues. In addition, 30 unique sequences were identified as highly expressed, with FPKM values of >3000, and most of these were biomineralization-related genes, including shematrin family genes, a jacalin-related lectin synthesis gene, calponin-2, and paramyosin. These findings will be useful for future studies of biomineralization in P. penguin, as well as in other Pteria species.

Elemental analysis of cultured pearls by PIXE

Cultured pearls are formed in pearl sacs comprising epithelial cells transplanted into mother-of-pearl. The formation mechanism is complicated and is still not fully understood. Previous studies have shown that the pearl formation is influenced by aquaculture environment and physiological activity of shellfish. The elemental compositions of seawater and freshwater pearls are significantly different. In this work, we used the particle-induced X-ray emission (PIXE) technique to perform elemental analysis of six types of pearls: ordinary and blue Akoya pearls, black-, gold-, and white-lipped oyster pearls, and freshwater Biwako pearl. We investigate the influence of trace elements in aquaculture environments on formation of mother-of-pearl or color. The Mn/Sr or Fe/Sr ratio for the freshwater pearl was found to be significantly higher than that for the seawater pearl. Comparing the sweater pearls, the gold-lipped oyster pearl has high value of Mn/Sr ratio. The Fe/Sr and Cu/Sr ratios for two Akoya pearls harvested from the Sea of Japan are relatively high compared with black-, gold-, and white-lipped oyster pearls from the South Sea.

Pearls in the ribbed mussel Aulacomya atra caused by polydorin polychaetes (Spionidae) infestation

Aulacomya atra populations of the San Jose gulf, Northern Patagonia, Southwestern Atlantic Ocean, are infested by two polydorin species, Polydora rickettsi and Dipolydora cf. giardi. The infestation by these boring polychaetes causes the formation of pearls which is evidenced by the presence of capsules containing polydorin tissue debris and the elemental composition of organic material inside the pearls. Moreover, a positive relationship between the abundance of perforations of polydorin polychaetes and abundance of pearls was found by applying generalized lineal model analysis. These results constitute the first evidence of pearls formation due to infestation by polychaete.

Chemomodulatory Potential of Flaxseed Oil Against DMBA/Croton Oil-Induced Skin Carcinogenesis in Mice.

The present study was conducted to evaluate the potential of flaxseed oil to prevent chemically induced skin cancer in mice. Cancer was induced on 2-stage skin carcinogenesis model by single topical application of 7,12 dimethylbenz [a]anthracene (DMBA), as, initiator, and two weeks later it was promoted by croton oil treatment thrice a week on the dorsal surface of mice for 16 weeks. Flaxseed oil (FSO; 100µL/animal/d) was orally administered 1 week before and 1 week after DMBA application (Peri-initiation stage). The animals of the FSO-administered group showed a significant reduction in tumor incidence (76.67%), cumulative number of tumors (37), tumor yield (3.7), and tumor burden (4.81) when compared with the carcinogen-treated control animals. Biochemical parameters in skin and liver tissue such as LPO and phase I enzymes were significantly (P < .01) reduced in the FSO-treated experimental group, whereas the phase II enzymes (GST, DT-diaphorase) and antioxidant parameters (GSH, GPx, SOD, catalase, and vitamin C) exhibited a significant (P < .01) elevation when compared with the animals of the carcinogen-treated control group. Histopathological alterations in the carcinogen-treated control animals were also observed in the form of epidermal hyperplasia, keratinized pearl formation, and acanthosis in skin and tumors, whereas these were found to be reduced after FSO administration. The results of the present study demonstrate that the oral administration of FSO has the potential to modulate the levels of LPO, antioxidants, and detoxification enzymes in the DMBA-croton oil–induced skin carcinogenesis in mice.

MP48-07 SUCCESSFUL MANAGEMENT OF CLITORODYNIA CLOSED COMPARTMENT SYNDROME

You have accessJournal of UrologySexual Function/Dysfunction: Surgical Therapy1 Apr 2016MP48-07 SUCCESSFUL MANAGEMENT OF CLITORODYNIA CLOSED COMPARTMENT SYNDROME Sherita King, Joshua Gonzalez, and Irwin Goldstein Sherita KingSherita King More articles by this author , Joshua GonzalezJoshua Gonzalez More articles by this author , and Irwin GoldsteinIrwin Goldstein More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.347AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES 24.7-36.8% of women complain of pain during sexual activity. Clitorodynia, a localized form of vulvodynia, is an uncommon, distressing, often disabling sexual pain syndrome with burning, stinging, and/or sharp pain confined to the glans clitoris, common clitoral shaft and/or prepucial area. The pain may be constant, intermittent or occurring only when provoked. The clitoral pain commonly increases with sexual activity, and is generally chronic. Women with clitorodynia are usually managed ineffectively with the same treatments used for generalized vulvodynia. METHODS We retrospectively reviewed prevalence and clinical management experience of distressing clitorodynia in our multidisciplinary sexual medicine facility in the last 5 years. RESULTS Of 430 women with vulvodynia we identified 15 with clitorodynia. The glans corona of 8 could not be identified on vulvoscopy, despite vigorous retraction maneuvers. Adjacent skin adhesions to the glans clitoris were identified and an oily waxy sebum material exuded through breaks in adhesions. Under higher magnification, keratin or epithelial pearl structures forming concentric layers 0.5-2 mm in diameter were seen under squamous skin epithelial adhesions. These 8 women underwent exploration, dorsal slit surgery and release of localized adjacent skin adhesions to the glans clitoris. In all 8 more than 50% of the glans was involved, balanitis noted below the glans skin adhesions above the corona. Two also had lichen sclerosis concomitantly managed with clobetasol. Six of 8 patients have significant improvement of clitoral pain at least 1 year postop. Of the 7 other women, 3 had clitoral priapism responding to adrenergic agonist treatment or shunt surgery, 2 had suffered blunt perineal trauma, suspected of having pudendal neuropathy, and 2 had blunt perineal trauma with clitoral neuromata on surgical exploration. CONCLUSIONS Clitorodynia, although rare, often appears to be caused by a closed compartment syndrome of adjacent skin adhesions to the glans clitoris, leading to underlying unrecognized balanitis, keratin pearl formation and chronic pain. If the corona of the glans clitoris cannot be visualized despite vigorous retraction, a closed compartment form of treatable chronic clitoral pain should be suspected. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e637-e638 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Sherita King More articles by this author Joshua Gonzalez More articles by this author Irwin Goldstein More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Natural Pearls

A literature less traveled – peaking between 1900-1920 – draws on pre-classical concepts of crystal growth and a trove of field biology, to understand ectopic shell production, the natural source of pearls. By 1907, grafts from the calcifying mantle epithelium on gonads induced nacre mineralization consistently in Pinctada margaritifera, suggesting that anomalously displaced, readily specialized cells are at least a sufficient cause of natural pearl formation. Otherwise, the epithelial sacks wrapping natural nacreous pearls must specialize for nacre production independently from the shell producing mantle – an idea supported by experiments with shell regeneration, but not amenable to a method of inducing pearl formation. At the time, chasing epithelial cell migration was technically unfeasible, signalling was news, stemness was fiction. Boldly, Jameson &amp; Rubbel [1902-1912] marshalled natural pearl nuclei and shell repairs as mineral records of cells specializing de novo into the shell’s secretory regimes. Much of this paper reenacts the historic debate on the origin of pearls: thence bold ideas connect smoothly with new work both on bone or shell. I replicate Jameson’s choice of samples and revisit his proposal to search for an “agency [other than the] shell-secreting mechanism“ acting on ”replacement cells” as the origin of pearls. Much has changed: specialized epithelial cells reportedly migrate; non-differentiated cells remain available throughout and near the calcifying mantle epithelium – both, open possibilities for natural pearl nucleation. Interest in understanding the latter now connects with results sketching the signalling cascade in cell specialization toward bone morphogenesis. Replicating Jameson’s choice of samples, I describe the more spectacular structural changes in the mineralization of pearls associated with two instances of cell specialization: toward producing one shell material – in the event of natural pearl nucleation, or switching between two in later pearl growth. Clusters of cells producing distinctly novel mineralization – nacre over fibrous-prismatic aragonite – could be singled out next to natural pearls by Jameson. The possibility has not been probed in roughly a hundred years. Natural pearl nucleation as a cellular event has never been explored.

Squamous cells and keratin pearls in fine-needle aspiration and frozen section: A pitfall in the diagnosis of ameloblastic carcinoma

Intraosseous involvement of jaw bones are commonly seen with squamous cell carcinoma (SCC) of the oral cavity. Ameloblastic carcinoma (AC) is a rare malignant odontogenic neoplasm that tends to occur in mandible with or without intraosseous involvement. We present one such rare case of, 60-year-old female with gray white growth in the left lower buccal cavity with enlarged lymph nodes. The computed tomography scan showed a mass from the left submandibular salivary gland and fine-needle aspiration was suggestive of malignant salivary gland tumor. The patient was posted for frozen section and mandibulectomy. Frozen section showed squamous cells with keratin pearl formation suggestive of metastatic SCC. The routine histopathology proved it as AC with keratin pearl formation. With this case, we would like to highlight the pitfalls, difficulties, and importance in the diagnosis of AC.

Controlled in Vivo Nacre Formation in Flat Pearls with Hydroxyapatite Bioceramic Nuclei

We carried out in vivo experiments of cultured flat pearl production using disc-like hydroxyapatite (HAp) bioceramics as a nucleus, with and without electric polarization treatment, and evaluated the effects of electric polarization and the quality of HAp materials on flat pearl formation. The thickness of the lamellar structures of the nacreous aragonite layers increased when polarized HAp pellets, instead of nonpolarized HAp pellets, as the nucleus, were used as the nuclei, while the thickness of the columnar structures of the prismatic calcite layers decreased. These phenomena were observed remarkably on the negative potential surface of the polarized HAp pellet. The electric polarization treatment promoted the formation rate of the nacreous lamella structure. It was speculated that electric polarization may control the physiological actions of mantle tissue and regulate the formation of the prismatic calcite and nacreous aragonite layers. The polarization treatment leads to an interference color with ...

The AP-1 transcription factor homolog Pf-AP-1 activates transcription of multiple biomineral proteins and potentially participates in Pinctada fucata biomineralization.

Activator protein-1 (AP-1) is an important bZIP transcription factor that regulates a series of physiological processes by specifically activating transcription of several genes, and one of its well-chartered functions in mammals is participating in bone mineralization. We isolated and cloned the complete cDNA of a Jun/AP-1 homolog from Pinctada fucata and called it Pf-AP-1. Pf-AP-1 had a highly conserved bZIP region and phosphorylation sites compared with those from mammals. A tissue distribution analysis showed that Pf-AP-1 was ubiquitously expressed in P. fucata and the mRNA level of Pf-AP-1 is extremely high in mantle. Pf-AP-1 expression was positively associated with multiple biomineral proteins in the mantle. The luciferase reporter assay in a mammalian cell line showed that Pf-AP-1 significantly up-regulates the transcriptional activity of the promoters of KRMP, Pearlin, and Prisilkin39. Inhibiting the activity of Pf-AP-1 depressed the expression of multiple matrix proteins. Pf-AP-1 showed a unique expression pattern during shell regeneration and pearl sac development, which was similar to the pattern observed for biomineral proteins. These results suggest that the Pf-AP-1 AP-1 homolog is an important transcription factor that regulates transcription of several biomineral proteins simultaneously and plays a role in P. fucata biomineralization, particularly during pearl and shell formation.

Clinical Pearls in perioperative medicine.

At the 2001 annual conference of the American College of Physicians, a new teaching format to aid physician learning, Clinical Pearls, was introduced. Clinical Pearls is designed with the 3 qualities of physician-learners in mind. First, we physicians enjoy learning from cases. Second, we like concise, practical points that we can use in our practice. Finally, we take pleasure in problem solving. In the Clinical Pearls format, speakers present a number of short cases in their specialty to a general internal medicine audience. Each case is followed by a multiple-choice question answered live by attendees using an audience response system. The answer distribution is shown to attendees. The correct answer is then displayed and the speaker discusses teaching points, clarifying why one answer is most appropriate. Each case presentation ends with a Clinical Pearl, defined as a practical teaching point that is supported by the literature but generally not well known to most internists. Clinical Pearls is currently one of the most popular sessions at the American College of Physicians meeting. As a service to its readers, Mayo Clinic Proceedings has invited a selected number of these Clinical Pearl presentations to be published in our Concise Review for Clinicians section. “Clinical Pearls in Perioperative Medicine” is one of them.

Experimental models for posterior capsule opacification research

Millions of people worldwide are blinded due to cataract formation. At present the only means of treating a cataract is through surgical intervention. A modern cataract operation involves the creation of an opening in the anterior lens capsule to allow access to the fibre cells, which are then removed. This leaves in place a capsular bag that comprises the remaining anterior capsule and the entire posterior capsule. In most cases, an intraocular lens is implanted into the capsular bag during surgery. This procedure initially generates good visual restoration, but unfortunately, residual lens epithelial cells undergo a wound-healing response invoked by surgery, which in time commonly results in a secondary loss of vision. This condition is known as posterior capsule opacification (PCO) and exhibits classical features of fibrosis, including hyperproliferation, migration, matrix deposition, matrix contraction and transdifferentiation into myofibroblasts. These changes alone can cause visual deterioration, but in a significant number of cases, fibre differentiation is also observed, which gives rise to Soemmering's ring and Elschnig's pearl formation. Elucidating the regulatory factors that govern these events is fundamental in the drive to develop future strategies to prevent or delay visual deterioration resulting from PCO. A range of experimental platforms are available for the study of PCO that range from in vivo animal models to in vitro human cell and tissue culture models. In the current review, we will highlight some of the experimental models used in PCO research and provide examples of key findings that have resulted from these approaches.

Highly expressed EGFR in pearl sac may facilitate the pearl formation in the pearl oyster, Pinctada fucata

Epidermal growth factor receptor (EGFR) plays an important role in cell growth, proliferation, differentiation and migration. Yet whether it functions in pearl formation or not is not reported. In this study, EGFR was cloned from the pearl oyster Pinctada fucata (named as Pf-EGFR) and its expression profiles were investigated. The cDNA was 2156bp long with an ORF of 1017bp encoding 338 amino acid residues. The deduced polypeptide contained an L domain and a cysteine-rich domain, consistent with the characteristics of ErbB family. The sequence of Pf-EGFR shared 22.78–56.71% identity with other EGFRs. The genomic sequence of Pf-EGFR consisted of six exons and five introns, being 5190bp in total length, and expressed in all the tested tissues with a higher expression level in the pearl sac (P<0.05). In situ hybridization showed that Pf-EGFR was specifically expressed on both the inner side of the outer fold and the outer side of the inner fold of the mantle, as well as on the whole pearl sac including the connective tissues. In addition, Pf-EGFR was markedly increased at larval metamorphosis, significantly higher than other development periods (P<0.05). These results indicated that the Pf-EGFR may facilitate pearl formation as well as larval metamorphosis.

Cytological Features of a Variant NUT Midline Carcinoma of the Lung Harboring the NSD3-NUT Fusion Gene: A Case Report and Literature Review.

Background. Nuclear protein in testis (NUT) midline carcinoma (NMC) is a very rare and aggressive malignancy. In more than two-thirds of these NMC cases, a fusion between NUT and BRD4 or BRD3 has been documented; other variants are rare. The cytology of NMC itself has been sparsely documented and that of variant NMC has never been reported. Case Presentation. A 36-year-old woman was admitted because of a rapidly progressing lung tumor with metastases to the breast and bone. We recently reported this patient as the first case of a variant NMC of the lung harboring an NSD3-NUT fusion, based on immunohistochemical and genetic analyses. Cytological material was available for the present review. A highly cellular smear contained a predominantly noncohesive pattern of monomorphic cells with diameters 2–2.5 times greater than those of small lymphocytes, with a round-to-oval nucleus, slightly irregular nuclear contours, variably prominent nucleoli, scant cytoplasm, and identifiable mitotic figures. Foci of stratification and overt pearl formation, including a dyskeratocyte, were occasionally observed. The necrotic background contained naked nuclei, karyorrhectic debris, apoptotic cells, and macrophages phagocytizing karyorrhectic debris; nuclear crushing was noted. Conclusion. The cytological features of a variant NMC of the lung are described for the first time.