Pathology of lung cancer: Case #1 presentation

38-year-old man, non smoker, unremarkable family and personal clinical history productive cough since November 2009, chest X ray showed multiple opacities in the right lower lobe CT scan showed a 5.4 cm-sized mass in the right hilar region, embracing the right main bronchus and extending to the station 7 and R2-4 LN; multiple opacities in the right lower lobe were interpreted as being inflammatory at bronchoscopy, a fungating mass was detected at the entrance of the right lower bronchus Case #1: Clinics summary

bronchial biopsy was considered as being poorly differentiated carcinoma, maybe squamous, for which the patient underwent two runs of platinum and docetaxel because of the rapid PD, a second bronchial biopsy was repeated, which confirmed the same diagnosis upon further PD, a second opinion was required on both bronchial biopsies five tissue fragments were reviewed Case #1: Clinics summary

H&E-stained section…

Immunohistochemistry p63 CK5/6 CK7 Syn p40

Ki-67 TTF1 SQCC, G3? SCLC, combined variant with SQCC? Adenosquamous carcinoma, G3? Ewing family sarcoma or another small round blue cell tumors? Another tumor type? What is your diagnosis?

Sudden keratinization of small undifferentiated cells…

NUT, nuclear protein in testis, on 15q14

Undiff./G3 carcinoma (SQCC) with NUT fusion genes –70%: NUT-BRD4 –30%: NUT-BRD3 or other still unknown genes (NUT-variants) NUT fusion genes associate with acetylated, active chromatin, preventing epithelial (squamous) differentiation and maintaining continuing cell proliferation

chromatin acetylation may be restored by –histone deacetylase inhibitors (HDACi) - vorinostat –BET protein inhibitors (BRD) - BETi …so engaging a program of squamous differentiation and arresting tumor cell growth in vitro …some response have been obtained in vivo (vorinostat)

NMC Germ cell tumors: dysgerminoma seminoma embryonal carcinoma

NUT protein NUT moAb: WT protein and fusion NUT-BRD4(3) or other still unknown genes WT protein is normally expressed in testis and ovary only NUT protein: testis

FISH analysis for t(15;19)(q14;q13) NUT gene BRD4 gene NUT/BRD4 Fusion gene

NUT midline carcinoma of the lung Final diagnosis the patient died 3 months later because of PD

all ages, especially young people or infants most often in the midline (mediastinum and head-neck), but not exclusively (parotid gland, orbit) extremely uncommon in the lung probably under-recognized and under-diagnosed, so the likelihood of facing with NMC in biopsy is not so negligible clinical outcome unfavorable in most cases, but rare long survivors are on record NUT midline carcinoma

some NMC are heavily keratinizing: think of this tumor if clinics is not completely fulfilling for conventional SQCC (midline or unusual position, young people, no smoking habit, rapid progression upon therapy) MoAB clone C52B1 (Cell Signaling Technology): sensitivity of 87%, specificity of 100%, most tumor cells are positive focal neuroendocrine differentiation may be seen: attention to avoid diagnosing SCLC (p40 and CK 5/6 in small cells) and relaying on p63 that may be detected in SCLC NUT midline carcinoma

SCLC: p40 always -ve SCLC: p63 +ve in 40%

Differential diagnoses: small cell round tumors (neuroblastoma, Ewing sarcoma, rhabdomyosarcoma, desmoplastic small round cell tumor…) high-grade hematologic malignancies melanoma high-grade endocrine carcinoma undifferentiated or poorly differentiated carcinomas (SNUC, EBV-driven non-keratinizing carcinoma of the nasopharynx, salivary gland tumors) extragonadal germ cell tumors NUT midline carcinoma

This diagnosis should be taken into account in any nonsmoking patient with poorly differentiated (squamous) carcinoma Morphology and IHC (excluding antibody to the NUT protein) are not definitively contributory for NMC NUT midline carcinoma

Male, 38-year-old, right lung (present case) Three additional cases –orbit –supraclavicolar region –para-pancreatic mass NUT protein by IHC in almost all tumor cells t(15;19)(q14;q13) NUT/BRD4 gene All cases run unfavorable clinical course despite therapy Original diagnoses had been undifferentiated neoplasms, NOS NUT midline carcinoma

Thank you…