Rare Histologic Pattern Research Articles

Lymphocytic Esophagitis

Background: Lymphocytic esophagitis (LyE) is a rare condition that has been reported in several case studies, but its diagnostic criteria and clinical significance are inconsistent. There are no established clinical associations, except for Crohn’s disease in children. Our study aimed to determine if patients with LyE have distinct demographic or clinical characteristics when compared with patients with increased intraepithelial lymphocytes (IEL) in their esophageal biopsy. Methods: We conducted a retrospective review of all esophageal biopsies between 2008 and 2023 in 2 medical centers. After excluding cases that met criteria for specific disorders, we identified all cases with increased IEL and compared their clinical, demographic, and endoscopic characteristics to those of LyE. Results: We identified 381 cases with increased IEL, of which 15 met the criteria for LyE. Patients diagnosed with LyE showed no distinctive demographic, endoscopic, or associated morbidities. The gradual increase in esophageal IEL was not associated with any differences in demographic, endoscopic, or clinicopathologic findings. Conclusion: Our findings suggest that lymphocytic esophagitis is not a well-defined clinicopathologic entity but rather a rare and nonspecific histologic pattern associated with various esophageal disorders. Further studies should aim to differentiate between the underlying causes of this histologic pattern, rather than defining it as a single clinicopathologic entity.

Airway-centered Interstitial Fibrosis: An Unusual Presentation

Airway-centered interstitial fibrosis (ACIF) is described as one of the interstitial lung diseases (ILDs) with rare histologic patterns. It is characterised by predominant airway involvement with centrilobular fibrosis, peribronchiolar metaplasia and bronchiolocentric inflammatory changes. We report the case of a female who presented with pneumothorax and central diabetes insipidus, diagnosed as ACIF on lung biopsy.

ACUTE FIBRINOUS ORGANIZING PNEUMONIA: A NEW ASSOCIATION

TOPIC: Lung Pathology TYPE: Fellow Case Reports INTRODUCTION: Acute Fibrinous and Organizing Pneumonia (AFOP) is a rare histological pattern of acute lung injury of unclear etiology. It can present with severe hypoxemia and characteristic bilateral basilar infiltrates meeting criteria for acute respiratory distress syndrome(ARDS). We present the case of a 48-year-old female with ARDS who was diagnosed with AFOP after an open lung biopsy. CASE PRESENTATION: A 48-year-old female with a past history of schizophrenia, hypertension, type 2 diabetes, osteoarthritis and monoclonal gammopathy of undetermined significance (MGUS) presented with cough and progressive shortness of breath, worsening acutely over three days. Upon arrival, the patient was hypoxic with oxygen saturation of 47%, on room air so she was emergently intubated. Initial chest X-ray revealed bilateral mid to lower zone infiltrates concerning for severe pneumonia (Picture 1). Chest CT-Angiogram ruled out pulmonary embolism. She was admitted to our intensive care unit and started on empiric broad spectrum antibiotics (Vancomycin/Piperacillin-Tazobactam/Levaquin) and ventilated using a lung-protective strategy for ARDS. Over the next 15 days, she remained ventilator dependent with high FiO2/PEEP requirements and eventually had a tracheostomy. Microbiological studies including bronchoscopic samples remained negative. An open lung biopsy was performed which showed lymphocyte and plasma cell infiltration and intra-alveolar fibrin balls with an absence of neutrophil/eosinophil infiltration and hyaline membrane formation typical of other well-recognized patterns of acute lung injury, leading to a diagnosis of AFOP (Picture 2). She was started on high dose steroids (methyprednisolone 60mg IV q8h) with prompt resolution of infiltrates and improvement in her oxygenation. DISCUSSION: (AFOP) is a rare histologic pattern of acute lung injury with multiple clinical associations but unclear etiology. Two clinical patterns have been described: i) an acute fulminant condition with severe hypoxemia and ii) a subacute respiratory illness. Diagnosis requires biopsy revealing intra-alveolar fibrin balls amidst an organizing pneumonia. AFOP has been described in patients with HIV infection, decitabine exposure, amiodarone toxicity, post hematopoietic stem cell transplantation, connective tissue diseases etc. Patients have been treated with corticosteroids, mycophenolate mofetil, cyclophosphamide, and cyclosporine with variable response. [1] CONCLUSIONS: In this case, monoclonal gammopathy of unknown significance (MGUS) represents a new association of AFOP and thus adds to our understanding of the clinical and pathological characteristics of this disease. REFERENCE #1: 1. Acute fibrinous and organizing pneumonia and undifferentiated connective tissue disease: a case report. Valim V, Rocha RH, Couto RB, Paixão TS, Serrano EV. Case Rep Rheumatol. 2012;2012:549298. doi: 10.1155/2012/549298. Epub 2012 Apr 4. DISCLOSURES: No relevant relationships by Sukhmani Boparai, source=Web Response No relevant relationships by Prangthip Charoenpong, source=Web Response No relevant relationships by Deon Ford, source=Web Response

Clinical features of acute fibrinous and organizing pneumonia: An early histologic pattern of various acute inflammatory lung diseases.

BackgroundAcute fibrinous and organizing pneumonia (AFOP) is a rare histologic pattern of acute lung involvement with intra-alveolar fibrin deposition. However, the clinical significance of the pathological findings of AFOP remains unclear. This study aimed to explore the clinical significance of AFOP through a comprehensive clinical examination.MethodsThe medical records of patients with lung diseases accompanied by the pathological finding of intra-alveolar organization between January 2010 and December 2019 were retrospectively reviewed. The clinical and radiological findings were compared between the groups with and without the histologic pattern of AFOP.ResultsWe identified 34 patients with AFOP (AFOP group) and 143 without AFOP (non-AFOP group). The underlying diseases of the AFOP group were as follows: 19 patients had cryptogenic organizing pneumonia (OP), 5 had connective tissue diseases, 3 had radiation pneumonitis, 3 had chronic eosinophilic pneumonia, 2 had myelodysplastic syndromes, and 2 had drug-induced pneumonia. Fever was more common, the time from symptom onset to biopsy was shorter, and the serum C-reactive protein level was higher in the AFOP group than in the non-AFOP group. On high-resolution computed tomography, 85% of patients had OP pattern, and halo sign was more common in the AFOP group. Corticosteroids were effective in 94% of the patients in the AFOP group; however, recurrences were more frequent, and a higher corticosteroid dose was needed during recurrence.ConclusionsAFOP might be an early phase of a histologic pattern associated with known etiologies. In addition, it could be a marker indicating intense inflammatory diseases with a tendency of recurrence.

Genomic characterization and molecular taxonomy of sarcomatoid variant prostate cancer.

168 Background: Sarcomatoid carcinoma is a rare and aggressive histologic variant pattern of prostate cancer with morphologic features associated with both mesenchymal and epithelial tissue elements. While sarcomatoid cancer can be found concurrently with adenocarcinoma in untreated specimens, it is most often encountered in post-treatment biopsies. Limited data is available to categorize genomic alterations in sarcomatoid prostate cancer or to genetically define any potential relationship between sarcomtaoid and adenocarcinoma patterns from the same patient. Methods: Clinical characteristics, histology, and genomic alterations for 5 cases of sarcomatoid prostate cancer and 2193 cases with adenocarcinoma are presented. All cases were analyzed for genomic alterations against a custom panel via Tempus xT tissue biopsy assay (DNA sequencing of 648 genes in tumor and matched normal samples at 500x depth and whole transcriptome RNA sequencing) for germline and/or somatic mutations. The xT assay detects single nucleotide variants, specific insertion/deletions, amplifications and gene fusions, as well as TMB and MSI status. Results: Patterns of genomic alterations in sarcomatoid cancer are tabulated and compared with adenocarcinoma. Of note, BRCA2 alterations were found in 2 of 5 sarcomatoid cases including 1 example of BRCA2 loss and 1 variant of undetermined significance (p.K2316R). Sequential analysis of samples from the subject with BRCA2 loss demonstrates genomic alterations that are shared across multiple samples despite different histologic patterns and following 14 months of treatment with GnRH antagonist and abiraterone (Table). Conclusions: Sarcomatoid prostate cancer shares many genomic alterations with that found in adenocarcinoma. Genomic characterization of this variant form of prostate cancer may reveal clinically actionable genetic changes. [Table: see text]

Update on Rare Idiopathic Interstitial Pneumonias and Rare Histologic Patterns.

- In 2013, the revised American Thoracic Society and European Respiratory Society classification of idiopathic interstitial pneumonias (IIPs) described 2 rare IIPs and 2 rare histologic patterns. Because of the rarity of the disease, there is limited evidence related to the histology. Because the rare histologic patterns are provisional criteria, no unanimous consensus on histologic diagnostic criteria has yet been reached. - To review the histologic features for rare IIPs and rare histologic patterns, and to provide diagnostic aids and discuss the differential diagnosis. - Published peer-reviewed literature and the authors' personal experience. - Following the publication of the international consensus classification, evidence regarding rare IIPs and rare histologic patterns has accumulated to some extent, although to date the amount remains insufficient and further evidence is required. Because the diagnosis is sometimes challenging, a multidisciplinary approach represents the gold standard in reaching an accurate diagnosis for these rare disorders.

A Rare Case of Idiopathic Interstitial Pneumonia With Good Outcome: Acute Fibrinous and Organizing Pneumonia

SESSION TITLE: Global Case Report Poster - Miscellaneous SESSION TYPE: Global Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Acute fibrinous and organizing pneumonia (AFOP) is a rare form of idiopathic interstitial pneumonia (IIP), which is now increasingly more recognized and has recently been added to the American Thoracic Society/European Respiratory Society international multidisciplinary classification of IIP. It is still regarded as a rare histologic pattern and is not yet classified as a new separate IIP entity. [1] Questions remain whether it is merely a histologic variant of existing IIPs or occurs in relation to other diseases such as hypersensitivity pneumonia or connective tissue disorder. It may also represent a histologic pattern that occurs in the clinical spectrum of diffuse alveolar damage and organizing pneumonia, and may reflect a tissue sampling issue. We report our experience with a case of AFOP treated successfully with corticosteroid and mycophenolate mofetil. CASE PRESENTATION: A 65-year-old Caucasian male, retired school teacher with no significant past medical history presented with progressive dyspnea and dry cough over 2 weeks. He had a 20-pack-year history of smoking, but quit 20 years ago. Regular medications included fish oil and glucosamine for knee osteoarthritis. There is no family history of similar presentation or connective tissue disorders. He was born in Australia and currently lived in a regional area, but with no exposure to farm animals. He had 1 pet dog. Hobbies included woodwork and gardening with regular exposure to mulch hay and potting mix. There were no sick contacts otherwise. There was no sputum production, hemoptysis, fever, night sweats or flu-like illness. He did have intentional weight loss of 6 kilograms over the last 3 months. There were no myalgia, arthralgia, sicca symptoms, abdominal or urinary symptoms. The only pertinent clinical finding was bilateral inspiratory crepitations without accompanying signs of overt heart failure. Initial chest x-ray demonstrated widespread interstitial and alveolar opacities. There was mild leukocytosis with neutrophilia. Interestingly, there was also a transient mild borderline eosinophilia. Urinalysis, renal and liver functions were unremarkable. Antibiotics for community-acquired pneumonia and diuretic therapies resulted in no improvement. A computed tomography pulmonary angiogram (CTPA) showed no pulmonary embolus. However, significant homogeneous bilateral ground-glass opacities and non-specific sub-pleural nodular infiltrates were demonstrated. There were no consolidation or significant lymphadenopathies. Bronchoscopy with transbronchial biopsy revealed no endobronchial abnormalities. Biopsies showed alveolar space filling by fibrin and macrophages, hyperplastic pneumocytes and mildly expanded interstitium with mild chronic inflammatory infiltrates. There were no granuloma, hyaline membrane, oesinophils, inclusion bodies, fibrosis or malignancy. All bacterial, mycobacterial and fungal cultures were negative. Viral PCRs were also negative. Infectious, hypersensitivity and autoimmune serologies were insignificant. A diagnosis of AFOP was made and the patient was commenced on Methylprednisolone followed by long-term prednisolone and additional Mycophenolate mofetil therapy for 6 months. Follow-up for the last 10 months showed complete radiological resolution with normalization and stability of diffusing capacity for carbon monoxide and 6-minute walk test. DISCUSSION: The classification of AFOP as a separate disease entity is still unclear, as it may belong to a spectrum of other interstitial pneumonias. Our experience posed a similar diagnostic challenge. There were risk factors and radiological evidence for hypersensitivity pneumonia, but histological and serological evidence were lacking. There has been a similar case report in which combined corticosteroid and mycophenolate therapy proved successful. [2] Our patient also received a similar therapy with success. CONCLUSIONS: AFOP is a rare form of idiopathic interstitial pneumonia. Combined corticosteroid and mycophenolate therapy may be effective in its treatment. Reference #1: Travis WD, et al. An official American Thoracic Society/European Respiratory Society statement: Update of the international multidisciplinary classification of the idiopathic interstitial pneumonias. Am J Respir Crit Care Med. 2013 Sep 15;188(6):733-48. Reference #2: Bhatti S, et al. Severe acute fibrinous and organizing pneumonia (AFOP) causing ventilatory failure: successful treatment with mycophenolate mofetil and corticosteroids. Respir Med. 2009 Nov;103(11):1764-7. DISCLOSURE: The following authors have nothing to disclose: Anuk Kruavit, Rebecca Pearson, Subash Heraganahally No Product/Research Disclosure Information

Rare idiopathic interstitial pneumonias: LIP and PPFE and rare histologic patterns of interstitial pneumonias: AFOP and BPIP.

In the 2013 reclassification of the idiopathic interstitial pneumonias (IIPs), two rare IIPs (idiopathic lymphoid interstitial pneumonia (LIP), idiopathic pleuroparenchymal fibroelastosis (IPPFE)) and two rare histologic patterns (acute fibrinous and organizing pneumonia (AFOP), bronchiolocentric pattern of interstitial pneumonia (BPIP)) are described. All these entities are rare with small series published to date, mostly containing primary and secondary forms of disease. LIP is histologically characterized by diffuse polyclonal lymphoid cell infiltrate surrounding the airways and expanding the interstitium. Thin-walled cysts and diffuse ground glass are considered the typical radiologic features. The clinical course is highly variable with corticosteroid responsiveness evident in approximately half of cases. IPPFE is defined histologically by coexisting upper lobe pleural and intra-alveolar fibrosis with elastosis. Dense subpleural irregular fibrosis and consolidation are the cardinal radiologic features. A history of recurrent lower respiratory tract infection is frequent. Responses to immunomodulation have not been reported and the rate of progression appears to be highly variable. AFOP is a rare histologic pattern lying within the spectrum of acute/subacute lung injury, characterized by organizing pneumonia and intra-alveolar fibrin deposition without hyaline membranes. BPIP is characterized histologically by fibrosis and/or inflammation confined to the alveolar interstitium around bronchovascular bundles, overlapping with peribronchial metaplasia and fibrosis in some series. Currently, AFOP and BPIP are both best viewed as histological entities rather than true clinical disorders, in the absence of characteristic associated imaging patterns and clinical features.

Pathology of Idiopathic Interstitial Pneumonias.

The updated classification of idiopathic interstitial pneumonias (IIPs) in 2013 by American Thoracic Society/European Respiratory Society included several important revisions to the categories described in the 2002 classification. In the updated classification, lymphoid interstitial pneumonia (LIP) was moved from major to rare IIPs, pleuroparenchymal fibroelastosis (PPFE) was newly included in the rare IIPs, acute fibrinous and organizing pneumonia (AFOP) and interstitial pneumonias with a bronchiolocentric distribution are recognized as rare histologic patterns, and unclassifiable IIP (UCIP) was classified as an IIP. However, recent reports indicate the areas of concern that may require further evaluation. Here, we describe the histopathologic features of the updated IIPs and their rare histologic patterns and also point out some of the issues to be considered in this context.

Rare idiopathic intestinal pneumonias (IIPs) and histologic patterns in new ATS/ERS multidisciplinary classification of the IIPs

The new American Thoracic Society/European Respiratory Society (ATS/ERS) update to the multidisciplinary classification of idiopathic interstitial pneumonias (IIPs) defines both rare IIPs and rare histologic patterns of IIPs. Although these diseases are rare, each has some distinguishing imaging and pathologic characteristics. Common findings for IIPs in computed tomography (CT) include cysts in lymphoid interstitial pneumonia (LIP), upper lobe subpleural consolidation in pleuropulmonary fibroelastosis (PPFE), symmetrical consolidation in acute fibrinous organizing pneumonia (AFOP), and peribronchovascular consolidation or centrilobular nodules in bronchiolocentric pattern of interstitial pneumonia.

The Morphologic and Molecular Characteristics of Pilocytic Astrocytomas and the Role of MAPK Pathway

In recent years, substantial progress has been made in the pathologic and molecular aspects of pilocytic astrocytomas. The advances in the pathologic characterization identified a variant that is currently considered WHO grade II, whereas the classic pilocytic astrocytoma is a WHO grade I neoplasm. Recognition of additional and rare histologic patterns also allowed us to better recognize some tumors that will do "well" in the long run. From a molecular pathologic perspective, recognition of the importance of MAPK pathways in these tumors allowed us to better understand tumors with spontaneous regression or dormant behavior, and tumors that become aggressive, especially those after radiation treatment. As the nature of this highly complex pathway is uncovered, we hope that the findings will allow us to better help the patients with this "chronic" disease.

Interstitial infiltration pattern in early morphea: clinicopathological analysis of 25 cases

Objective To estimate the diagnostic value of interstitial infiltration pattern for early morphea.Methods Twenty-five cases of early morphea pathologically characterized by interstitial infiltration of inflammatory cells were collected from 2010 to 2012.The clinicopathological features of these cases were retrospectively analyzed.Results The average clinical course was 7.5 months.The primary manifestation was edematous dark erythematous plaques,and interstitial or mixed infiltrate of inflammatory cells was the characteristic histopathological presentation.After anti-inflammatory treatment,lesions markedly improved or disappeared in 70％ of these patients.Conclusions Interstitial infiltration of inflammatory cells is a rare histologic pattern in early morphea.To learn and recognize this pattern may be beneficial to the diagnosis and treatment of early morphea. Key words: Scleroderma, localized; Histology; Inflammation; Cells

An Official American Thoracic Society/European Respiratory Society Statement: Update of the International Multidisciplinary Classification of the Idiopathic Interstitial Pneumonias

In 2002 the American Thoracic Society/European Respiratory Society (ATS/ERS) classification of idiopathic interstitial pneumonias (IIPs) defined seven specific entities, and provided standardized terminology and diagnostic criteria. In addition, the historical "gold standard" of histologic diagnosis was replaced by a multidisciplinary approach. Since 2002 many publications have provided new information about IIPs. The objective of this statement is to update the 2002 ATS/ERS classification of IIPs. An international multidisciplinary panel was formed and developed key questions that were addressed through a review of the literature published between 2000 and 2011. Substantial progress has been made in IIPs since the previous classification. Nonspecific interstitial pneumonia is now better defined. Respiratory bronchiolitis-interstitial lung disease is now commonly diagnosed without surgical biopsy. The clinical course of idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia is recognized to be heterogeneous. Acute exacerbation of IIPs is now well defined. A substantial percentage of patients with IIP are difficult to classify, often due to mixed patterns of lung injury. A classification based on observed disease behavior is proposed for patients who are difficult to classify or for entities with heterogeneity in clinical course. A group of rare entities, including pleuroparenchymal fibroelastosis and rare histologic patterns, is introduced. The rapidly evolving field of molecular markers is reviewed with the intent of promoting additional investigations that may help in determining diagnosis, and potentially prognosis and treatment. This update is a supplement to the previous 2002 IIP classification document. It outlines advances in the past decade and potential areas for future investigation.

Nitrofurantoin-Induced Granulomatous Interstitial Pneumonia

Nitrofurantoin-induced lung toxicity is relatively common, but rare histologic patterns sometimes occur that may make diagnosis difficult. We present the case of a 69-year-old woman taking prophylactic nitrofurantoin for urinary tract infections, who developed granulomatous interstitial pneumonia. She improved with cessation of nitrofurantoin, without other therapy. To our knowledge, this is the fourth reported case of granulomatous interstitial pneumonia associated with nitrofurantoin, and the first to show complete resolution with cessation of the drug alone, without steroids. It is important to recognize that idiosyncratic reactions to nitrofurantoin can produce a wide spectrum of histologic patterns. Of these patterns, granulomatous interstitial pneumonia is a rarely evidenced manifestation (possibly because few cases undergo a confirmatory lung biopsy). Recognition of granulomatous interstitial pneumonia as a manifestation of nitrofurantoin toxicity can aid in early identification of the reaction and prompt withdrawal of the drug, both of which are essential to prevent long-term complications.

The Histomorphologic Spectrum of Primary Cutaneous Diffuse Large B-Cell Lymphoma: A Study of 79 Cases

Primary cutaneous large B-cell lymphomas (PCLBCL) have historically been a matter of debate in the literature. The 2005 World Health Organization-European Organization for Research and Treatment of Cancer (WHO-EORTC) classification scheme segregated cutaneous B-cell lymphomas into 3 groups: primary cutaneous marginal zone B-cell lymphoma, primary cutaneous follicle center cell lymphoma, and primary cutaneous diffuse large B-cell lymphoma (PCDLBCL), "leg type" (PCDLBCL-LT). Additionally, the WHO-EORTC classification scheme utilized the term PCLBCL "other" not otherwise specified (NOS) type for rare cases of PCLBCL not belonging to either the "leg type" or the primary cutaneous follicle center cell lymphoma group. In this study, we retrospectively assessed the histomorphologic features of 79 cases of PCDLBCLs, including those of "leg type" and "other" NOS type, to further categorize the histologic spectrum of these unusual cutaneous neoplasms. The histologic diagnosis of PCLBCL usually poses little diagnostic difficulty; however, some cases may adopt unusual or unfamiliar appearances mimicking other lymphoproliferative disorders or other malignant neoplasms. Seventy-nine cases, occurring in 37 men and 42 women, aged 34-94 years, were analyzed. Fifty-three cases were classified as "leg type" and 26 cases were classified as "other" NOS type using the WHO-EORTC classification. Of the 53 cases classified as "leg type," 33 were women and 20 were men; of the 26 cases of "other" NOS type, 9 were women and 17 were men. In the "leg type" category, 31 cases were located on the lower extremities, 5 cases on the face, 5 cases on the arm, 3 cases on the chest, 2 cases on the shoulder, 2 cases on the back, 1 case on the trunk, 1 case on the buttock, 1 case on the supraclavicular area, 1 case on the head, and 1 case on the flank. Of the "other" NOS type category, 8 cases were located on the face, 5 cases on the shoulder, 3 cases on the head, 2 cases on the abdomen, 2 cases on the chest, 1 case on the trunk, 1 on the vulva, 1 on the axilla, 1 on the back, 1 on the neck, and 1 on the hip. Most cases assessed showed the classic morphologic appearance of PCDLBCL, but cases mimicking Burkitt lymphoma (starry-sky pattern), natural killer-cell (NK) lymphoma, mycosis fungoides (epidermotropism), low-grade B-cell lymphomas, epithelial malignancies, and Merkel cell carcinoma were encountered in this series. The high frequency of these rare histologic patterns can be explained by a bias associated with consultation practice. Careful histologic examination and immunohistochemical stains were used to establish the correct diagnosis. The differential diagnosis of PCDLBCL is broad and difficult to define histologically. Knowledge of these rare histologic variants is necessary to avoid misinterpretation of these cases as nonlymphoid malignancies.

Large solitary fibrous tumor of the seminal vesicle

Solitary fibrous tumors show a classic morphologic pattern (“patternless pattern”) consisting mainly of a proliferation of bland spindle cells with varying amounts of thick, often hyalinized or keloid-like, intercellular collagen bundles. Immunohistochemistry shows a strong reactivity for CD34 antigen, vimentin, and, in a variable percentage, bcl-2 antigen. We report the case of a 50-year-old man with a large solitary fibrous tumor located in the pelvic cavity with a rare nonspecific histologic pattern of pseudovascular formations. The patient underwent pelvic exenteration with orthotopic continent urinary diversion and sigmoid- J-pouch bowel reconstruction. No signs of tumor recurrence were noted within 24 months of surgery.

Pure Small-Cell Carcinoma of the Prostate With Fatal Liver Metastasis

A case of small-cell carcinoma (SCC) of the prostate is described with extensive liver metastases in a 60-year-old man. The case is unique because of the rare histologic pattern coupled with death secondary to hepatic failure. A spectrum of neuroendocrine tumors are found in the prostate similar to those found in the lung. Ten cases of prostatic SCC or carcinoid, identified in the English-language literature over a period of 14 years, are summarized. In the absence of an apparent pulmonary lesion, surgical pathologists should also consider the prostate as a primary site for extrapulmonary SCC when confronted with biopsy material of metastatic SCC.