Surgical Pathology

Acquired conjunctival melanocytic lesions include nevi, primary acquired melanoses (PAMs), and melanomas. Conjunctival melanoma is a malignant melanocytic neoplasm with a high metastasis and mortality rate. Usually, the diagnosis can be achieved only with routine microscopic analysis, but in some cases, the samples are small or have artifacts. In these cases, complementary studies will be helpful, but currently, there are no well-understood or studied complementary methods. Objective. To analyze the immunohistochemical expression of p16 in conjunctival melanocytic lesions and to assess its potential for differentiating between benign and malignant melanocytic lesions. Methods. Immunohistochemical study against p16ink4a (p16) was performed on paraffin-embedded sections on 45 melanocytic lesions (9 melanomas, 19 nevi, and 2 PAMs with atypia and 15 without atypia). Expression was scored according to the German immunoreactive score (IRS). Results. Expression of p16 IRS differed between nevi, PAMs, and melanomas. The mean IRS for melanomas was 3.3 ± 1.8 and was lower than those for nevi (7.63 ± 3.24; P < .05), PAM with atypia (12 ± 0; P < .05), and PAM without atypia (11 ± 1.69; P < .05). Lesions with infiltration depths lower than 2 mm showed higher levels of p16. There were no differences between favorable and unfavorable locations. Conclusion. p16 Expression in conjunctival melanocytic lesions showed an expression similar to that in skin and seems to be a good marker to differentiate nevi and PAMs from melanomas. However, additional studies of larger series and follow-up are needed to confirm these findings.

Expression profiling by microarrays and real-time polymerase chain reaction-based assays is a powerful tool for classification and prognostication of disease; however, it remains a research tool, largely reliant on frozen tissue. Limiting the utility of expression profiling is the isolation of quality nucleic acids from formalin-fixed, paraffin-embedded tissue. The collection, handling, and processing of tissue directly impacts the biomolecules that can be recovered from it. High-quality nucleic acids can be obtained from formalin-fixed, paraffin-embedded tissue, but greater attention to all steps in the process of tissue handling and preparation is required. To summarize the current state-of-the-art of preanalytic factors in tissue handling and processing as they impact the quality of RNA obtainable from formalin-fixed, paraffin-embedded tissue. The goals are to provide recommendations that will improve RNA quality for expression profiling from formalin-fixed, paraffin-embedded tis...

Lipomas are common benign tumors most frequently found within the subcutaneous areas of the body. Deep-seated lipomas are rare and tend to be larger than cutaneous ones. Lipomas are rarely seen in the thoracic cavity, and they are usually located in the mediasti-num, bronchiole, and lungs. Diaphragmatic lipomas have been occasionally reported in the literature, the first being described by Clark et al. in 1886. The authors report two rare cases of giant diaphragmatic lipoma incidentally found during forensic autopsies. In the first case, a Cauca-sian 85-year-old woman burned to death with another passenger, after her methane-fueled car collided with another car on a highway near Terni, Umbria, Italy. In the second case, a Caucasian 45-year-old man collapsed while walking through the countryside of Perugia. In either case, a large mass in the thorax was observed. The definitive pathologic diagnosis was giant intrathoracic diaphragmatic lipoma without evidence of malignancy. The authors also review the relevant literature and discuss differential diagnoses. These case reports contribute to the establishment of the actual incidence of diaphragmatic lipomas.

The aim of this study was to describe the clinicopathologic features of 177 keratocystic odontogenic tumors (KCOTs) diagnosed in a Brazilian population. A total of 177 KCOTs were reviewed and affected 158 patients with ages ranging from 5 to 79 years (mean age = 32 years) with a slight female predominance. Mandible was the most common affected site (69.3%), and a unilocular radiolucency was the most common radiographic image. Microscopically, all cases showed at least focal areas of classic KCOT, but several histological aspects were also observed, including diffuse and focal epithelial lining hyperplasia (48.6%), epithelial budding (12.4%), reactive cytological alterations (11.3%), dystrophic calcification (7.9%), daughter cysts (7.8%), odontogenic epithelial remnants (4.5%), focal areas of orthokeratinization (2.8%), and ameloblastomatous epithelium (1.7%). These variations may make KCOT diagnosis challenging in some cases, so careful full-sample analysis and knowledge of these un...

Typically the retro-mandibular vein contributes to formation of common facial and external jugular veins, via its anterior and posterior divisions re-spectively. However, cervico-facial venous variants are rather common. In two successive cadaver dissections the left side of head and neck were unviewable, but the right cervico-facial veins were visible. In both cadavers the right retro-mandibular vein was undivided. The first specimen had right external jugular vein draining into the right subcla-vian vein but did not have a right common facial vein. The second specimen did not have a right external jugular vein, but had a right common faci-al vein draining into the right internal jugular vein.
The first variant was characterized as Posterior Dominant Retromandibular Vein with no Common Facial Vein. The second variant was characterized as Anterior Dominant Retromandibular Vein with no External Jugular Vein. Each was sub-classified as Typical or Atypical based on its final drainage pattern. Cervico-facial venous variants often vary from case to case and side to side. Since external jugular and common facial veins are used for clini-cal and surgical interventions, accurate and struc-tured preoperative classification of variations may preclude intra-operative surprises and consequent complications.