Pulmonary adenofibroma: clinicopathological study of 3 cases of a rare benign lung lesion and review of the literature.

Pulmonary adenofibroma is a rare benign biphasic tumor of the lung composed of epithelial and stromal components. We report 3 cases of this unusual lesion of lung in a male (25 years old) and 2 female (40 and 55 years old) patients. Breathlessness on exertion and mild left-sided chest pain of 1 month's duration were the main concerns in 2 patients, whereas the third had cough and hemoptysis for 3 months. Chest radiograph and computed tomography scan revealed a well-circumscribed, subpleural homogenous mass in left lower chest fields in 2 cases and solid-cystic lesion in left upper lobe in the third patient. All 3 patients underwent lobectomy, following biopsy in 2 cases. Histology revealed a well-circumscribed lesion composed of complex glandlike spaces lined by cuboidal to columnar epithelium surrounded by a hyalinized spindle-cell fibroblastic proliferation reminiscent of adenofibroma of the female genital tract or fibroadenoma of the breast. Immunohistochemical examination supported the diagnosis of a benign pulmonary adenofibroma. All 3 patients were are alive and doing well with no evidence of recurrent or metastatic disease. Diagnosis on biopsy can be challenging and may be misinterpreted as well-differentiated adenocarcinoma with extensive fibrosis or low-grade sarcoma. Frozen-section consultation will be a valuable adjunct in planning for limited lung resection of this benign lung lesion. Although we described 3 cases of pulmonary adenofibroma, still this is the largest published series of this rare entity till date. The possible histogenesis and various differential diagnoses are discussed along with literature review.

Toward an evidence-based proposal for the best minimal immunohistochemical panel to infer lung carcinoma in metastatic supraclavicular lymph node.

Carcinomas from either pulmonary or extrapulmonary sites can metastatise to supraclavicular lymph nodes. Immunohistochemistry (IHC) is invaluable to comment on the possible primary site. However, the optimal number of antibodies to be tested is debatable. Seven antibodies were tested on 135 metastatic supraclavicular lymph node biopsies to propose a "best minimal" IHC panel to infer lung carcinoma, incorporating the principles of "evidence-based medicine." The 135 cases were divided into the following: category I (110 cases), wherein the primary was in the lung based on histologic analysis (Ia, n = 14 [12.7%]), cytologic analysis (Ib, n = 43 [39.1%]), or strong clinicoradiologic evidence (Ic, n = 53 [48.2%]), and category II (25 cases) with a histologically proven extrapulmonary primary site. Categories Ia and Ib were together designated as the "control group," and category Ic was designated as the "test group." The antibodies tested were cytokeratin (CK 7, CK20), epithelial membrane antigen, carcinoembryonic antigen, thyroid transcription factor-1 (TTF-1), surfactant protein B (SPB), and vimentin. Results of both individual and panels of antibodies were statistically evaluated. The sensitivity and specificity of single antibodies for inferring a lung primary was as follows: CK7 (90%/56%), CK20 (98%/40%), epithelial membrane antigen (90.9%/4%), carcinoembryonic antigen (80.9%/36%), TTF-1 (62.7%/100%), SPB (65.6%/100%), and vimentin (60.9%/60%). The highest sensitivity (85%) and specificity (100%) were seen with a 4-antibody panel: CK7, CK20, TTF-1, and SPB. This panel revealed the highest binomial probability (.8), for diagnosing lung cancer. The results were validated using a "split sample method," and a high concordance was noted between the control and test groups. To conclude, such evidence-based validated studies analyzing IHC results would be invaluable to guide the practice of surgical pathology in the future.

Primary extranodal histiocytic sarcoma of lumbar spine.

A 17-year-old male patient presented with lower back pain and weakness of lower limbs. On radiological investigation, a destructive bony lesion involving the third lumbar vertebra was seen associated with soft tissue extension and an extradural component. The lesion was surgically excised in view of the rapidly progressing symptoms. The histologic diagnosis was histiocytic sarcoma. Further investigations did not reveal any other lesion elsewhere. The case is being presented in view of the uncommon occurrence of a primary extranodal histiocytic sarcoma of the lumbar spine, which simulated a primary bone tumor.

Osteosarcoma of the femur mimicking Ewing sarcoma/primitive neuroectodermal tumour on biopsy and metastatic carcinoma on resection.

Osteosarcoma (OS) is known to have several morphological appearances, small cell osteosarcoma and epithelioid osteosarcoma being two well recognized patterns. The former can be mistaken for a Ewing sarcoma/primitive neuroectodermal tumour (ES/PNET), whereas the latter mimics metastatic carcinoma. Herein we present an osteosarcoma in a 17-year-old girl that was diagnosed as an ES/PNET on biopsy; however, the resected specimen revealed a very unusual morphology mimicking a metastatic carcinoma with a sex cord stromal tumour-like pattern.

Rhinosporidiosis isolated to the distal clavicle: a rare presentation clinicoradiologically mimicking a bone tumor.

Rhinosporidiosis is a chronic granulomatous disease caused by Rhinosporidium seeberi, which commonly affects young men and predominantly involves the mucous membranes of the nose, nasopharynx and eyes. Involvement of extranasal sites including bone has been reported, but rarely. We present a case of a 32-year-old farmer, who presented with a non-tender, fixed swelling over his right shoulder. Radiography and CT imaging showed an expansile, lytic, destructive lesion involving the lateral end of the right clavicle with soft tissue extension. The clinicoradiological impression was that of a primary bone tumor. Biopsy and wide excision of the lesion revealed features of rhinosporidiosis. There were no mucocutaneous lesions. Involvement of bone without associated mucocutaneous lesions is exceedingly rare in rhinosporidiosis. Involvement of the clavicle, as seen in the present case, has not been reported in the English language-peer reviewed literature, to the best of our knowledge.

Phosphaturic mesenchymal tumor with chondromyxoid fibroma-like feature: an unusual morphological appearance.

Phosphaturic mesenchymal tumor (PMT) is a rare and distinctive tumor almost always associated with oncogenic osteomalacia. This tumor is often misdiagnosed due to its widely varied histomorphological spectrum. More recently the term PMT or its variants has been used whatever the histomorphological features. Herein, we present a case of a 32-year-old woman who presented with a 2-year history of oncogenic osteomalacia. The clinical examination failed to detect any tumor. The F-18 FDG PET scan and subsequent MRI revealed a tumor in the soft tissues of the right popliteal fossa. The histological features resembled a chondromyxoid fibroma (CMF), a feature documented only in two cases so far.

ALK+ anaplastic large cell lymphoma with cohesive, perivascular arrangements on cytology, mimicking a soft tissue sarcoma: a report of 2 cases.

BACKGROUND: An accurate recognition of a lymphoma at an extranodal site is essential to avoid unnecessary excisions. Fine needle aspiration cytology (FNAC) has been recognized as a useful tool in the primary diagnosis of soft tissue tumors. An anaplastic large cell lymphoma (ALCL), occurring in soft tissues, poses a diagnostic challenge. We present the cytomorphology of 2 cases of anaplastic lymphoma kinase (ALK)+ ALCL that displayed a perivascular arrangement, thereby mimicking a sarcoma. CASES: The patients were aged 16 and 9 years. While the former presented with multiple nodular soft tissue and bony lesions over the body, the latter complained of an axillary lump. FNAC smears in both cases showed pleomorphic cells, arranged in loosely cohesive groups around blood vessels and scattered singly, with prominent nucleoli and abundant, finely vacuolated cytoplasm. Interspersed were a few cells with embryoid nuclei. Differential diagnoses included a rhabdomyosarcoma and a lymphoma. On biopsy and immunohistochemistry, tumor cells were positive for vimentin, LCA, EMA, CD30 and ALK. CONCLUSION: ALCL should be considered in the differential diagnosis of pediatric soft tissue tumors, especially in cases with multifocal involvement. The presence of cohesive, perivascular arrangements on FNAC should not detract a cytologist for keeping this possibility in mind. Further, a careful search for the typical "hallmark" cells should be made.

Immunohistochemistry in surgical pathology practice: a current perspective of a simple, powerful, yet complex, tool.

Immunohistochemistry (IHC) is a powerful tool in the surgical pathologists' armamentarium. The requests for IHC and the list of monoclonal antibodies have increased tremendously in the past decade. Issues concerning technical reproducibility, uniformity of interpretation, inter-laboratory comparability, and quality assurance are assuming greater importance due to the increased availability of IHC and its impact on diagnosis and therapy. An attempt has been made to give a current perspective of this simple and yet, in some aspects, a complex tool.

Sclerosing epithelioid fibrosarcoma - a report of two cases with cytogenetic analysis of FUS gene rearrangement by FISH technique.

Sclerosing epithelioid fibrosarcoma (SEF) is a rare soft tissue sarcoma. Recently, a link has been suggested between SEF and low-grade fibromyxoid sarcoma (LGFMS) on the basis of the finding of the characteristic translocation t(7;16) (FUS-CREB3L2) of LGFMS in a small number of studied cases of SEF. The frequency of this translocation in SEF is still unknown. We present 2 cases of SEF with cytogenetic analysis for FUS rearrangement. The tumors occurred in 12 and 58 year old patients, respectively and consisted of a well to partially circumscribed, non-encapsulated mass, comprising monomorphic, polygonal cells arranged in aggregates, cords and single file arrays in a variably sclerotic stroma. The cells exhibited minimal nuclear atypia with moderate amount of clear to eosinophilic cytoplasm and rare mitotic figures. One case also showed bland spindle cell areas with myxoid change, as seen in LGFMS. By immunohistochemistry (IHC), the tumor cells were diffusely positive for vimentin, focally for S-100 in 1 case and negative for cytokeratin (CK), epithelial membrane antigen (EMA), HMB-45, desmin, smooth muscle actin (SMA), H-caldesmon, Myo D-1, CD34 and CD 168. By fluorescent in-situ hybridization (FISH) technique, the case with mixed SEF and LGFMS histology was positive for FUS rearrangement. Our study reinforces the previously reported relationship between SEF and LGFMS, and suggests that SEF may represent a variant of LGFMS in at least some cases, rather than an entirely distinct fibrosarcoma variant.

Primary endobronchial synovial sarcoma confirmed by SYT-SSX1 fusion gene transcript by reverse transcriptase polymerase chain reaction.

Primary sarcomas of lung are rare compared to metastatic sarcomas. Herein, we report a rare case of primary pulmonary synovial sarcoma with polypoid endobronchial growth in a 35-year-old lady who presented with cough and dyspnea. A malignant pulmonary tumor was suspected and left pneumonectomy was performed. Grossly, a non-encapsulated polypoidal endobronchial tumor measuring 6 cm in greatest diameter, with a solid, tan-white cut surface was identified. Microscopically, tumor was characterized by a proliferation of oval to spindle-shaped cells arranged in sheets and fascicles. Focal hemangiopericytomatous pattern was noted. Immunohistochemically, tumor cells were positive for vimentin, BCL-2, MIC-2 and calponin and focally positive for pancytokeratin and epithelial membrane antigen. A subsequent molecular analysis performed using reverse transcriptase-polymerase chain reaction with RNA extracted from paraffin-embedded tissue, revealed SYT/SSX1 fusion gene which confirmed the diagnosis of synovial sarcoma. The utility of immunohistochemistry and molecular techniques in diagnosis of such a rare case is stressed and the relevant literature is discussed.