Lung cancer histologic and immunohistochemical heterogeneity in the era of molecular therapies: analysis of 172 consecutive surgically resected, entirely sampled pulmonary carcinomas.

On the basis of seminal studies in the 1980s, appreciable histologic heterogeneity, ranging from 45% to 70% of cases, may be encountered in lung cancer. However, the epidemiologic and histologic landscape of lung cancer in the last 3 decades has radically changed. In this study, 172 consecutive surgically resected primary lung carcinomas evaluated from 2010 to 2012 were entirely sampled and examined according to current histologic classifications. In 129 cases, a positive preoperative biopsy was also available. Major histologic heterogeneity (a single tumor showing at least 2 different histologic types) and minor histologic heterogeneity (a single tumor showing just 1 histologic type but at least 2 different growth patterns) were evaluated in all cases. Immunohistochemical heterogeneity (ie, "aberrant" staining) was also assessed using a panel of markers of adenocarcinoma (TTF-1, napsin, and CK7), squamous cell carcinoma (p63, CK5/6), and neuroendocrine differentiation (chromogranin and synaptophysin), both on positive biopsies and surgical specimens. Overall, major and minor histologic heterogeneity on resections were disclosed in 4% (7 cases) and 50.6% (87 cases), respectively, whereas just 1 case of minor heterogeneity (pleomorphic carcinoma) was observed on biopsies. Minor heterogeneity was limited to adenocarcinomas (82.6%, 81/98 cases) and sarcomatoid carcinomas (6 pleomorphic types among 8 sarcomatoid carcinomas). Immunohistochemical heterogeneity was recorded in 22.6% of the cases, with expression of p63 and CK5/6 in a subset of adenocarcinomas (25 cases, 25.5%), CK7 in 17.4% of squamous cell carcinomas, and synaptophysin in 6 cases of non-neuroendocrine tumors (4%, 6/155). The high rate of adenocarcinomas, accounting for 57% (98 cases) of 172 consecutively resected lung cancers, reflects the new scenario of thoracic oncology and may explain the significant lower rate of major histologic heterogeneity (4%) and the higher frequency of different architectural patterns (minor heterogeneity) that we found in lung cancer compared with previous studies.

A case of frozen pelvis: primary actinomycosis of urinary bladder in a young boy.

We report a case of urinary bladder actinomycosis in childhood. In children abdominal actinomycosis is rare and unlikely involves the urinary tract, so it is often misdiagnosed. An 7-year-old boy was referred to a secondary level hospital because of abdominal pain and dysuria. Physical examination revealed a left hypochondrial mass. Hypothesizing a pelvic rhabdomyosarcoma, a biopsy with mini-laparotomy access was performed. The first histopathological analysis did not show any malignant cells, and a 14-day antibiotic course was ineffective. Reoperation and biopsy was needed, and the histopathological examination made the diagnosis possible.

Primary pulmonary cancer colliding with metastatic breast carcinoma: hitherto unreported cases of cancer-to-cancer metastasis focusing on clinical implications.

Lung is one of the main sites of metastatic tumors, but collision neoplasms consisting of a primary lung cancer and metastatic breast carcinoma have never been so far reported. We describe here 2 cases of primary non-small cell lung cancers (squamous cell and adenocarcinoma, respectively) colliding with metastatic breast carcinomas (ductal and lobular carcinomas, respectively). Clinico-pathologic features characterizing this challenging diagnosis and the important therapeutic implications are discussed.

EGFR and K-ras mutations along the spectrum of pulmonary epithelial tumors of the lung and elaboration of a combined clinicopathologic and molecular scoring system to predict clinical responsiveness to EGFR inhibitors.

We tested 418 neoplasms along the whole spectrum of primary lung tumor histotypes for epidermal growth factor receptor (EGFR) and K-ras mutations. Clinicopathologic data from 154 patients undergoing treatment with EGFR tyrosine kinase inhibitors (TKIs) were retrospectively studied. A scoring system assigning a score for each positive or negative characteristic (+1, female sex, nonsmoking status, adenocarcinoma histotype, Asian ethnicity, and EGFR mutation; -1, current smoker and K-ras mutation; and 0, male sex, ex-smoker, nonadenocarcinoma histotype, and no mutations) was elaborated and tested with EGFR-TKI response. Salivary gland-type, mucin-rich, and neuroendocrine tumors do not harbor EGFR mutations. A subset of nonmucinous adenocarcinomas, not necessarily of the bronchioloalveolar type, is related to EGFR mutations. Three probability groups significantly correlating with response to EGFR-TKIs were identified. Of note, the addition of molecular results did not significantly change the predictive value obtained by the combination of clinicopathologic characteristics alone in this scoring system. K-ras mutations, significantly associated with the mucin-secreting type of adenocarcinoma, consistently predict lack of response in white patients.

Heavily pigmented renal cell carcinoma: a case report, with review of the literature and differential diagnosis.

Clear cell carcinoma is the most common histotype among renal cell tumors. The prominent vascular network of sinusoidal vessels lined by delicate endothelial cells may often lead to hemorrhagic areas with secondary deposition of chunky birefringent hemosiderin granules. The finding of pigmentation other than iron, and in particular melanin deposits, in renal tumors is a rare occurrence that should lead to differential diagnosis with other primary and metastatic tumors of the kidney.

Double synchronous pulmonary lymphatic-related lesions.

A wide range of pathologies may primarily affect the lymphatic vessels in the lungs. In this article, a unique case of pulmonary silicosis associated with a subtle lymphangitic carcinomatosis from an unknown prostate cancer is reported and discussed.