ALK-negative lung inflammatory myofibroblastic tumor in a young adult: A case report and literature review of molecular alterations

RATIONALE

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor that is prevalent among children and adolescents. Surgery is the most important therapeutic approach for IMT and complete resection is recommended. Although 50% of IMTs show anaplastic lymphoma kinase (ALK) rearrangements, crizotinib has proven an effective therapeutic approach. However, the genetic landscape of this tumor is still not fully understood and treatment options are limited, especially in the majority of ALK-negative tumors.

PATIENT CONCERNS

We describe the clinical case of a healthy 18-year-old female in whom a pulmonary nodule was incidentally detected.

DIAGNOSES

Following a small increase in the size of the nodule, the patient underwent both 18FDG-PET/CT and 68Ga-PET/CT, resulting in a suspicion of bronchial hamartoma.

INTERVENTIONS

The patient underwent surgery and a salivary gland-like lung tumor was diagnosed.

OUTCOMES

After surgery, the patient was referred to our cancer center, where a review of the histology slides gave a final diagnosis of ALK-negative lung IMT. Given the histology, it was decided not to administer adjuvant therapy and the patient was placed in a 3-monthly follow-up program. The patient is still disease-free 2 years post-surgery.

LESSONS

Although there is no standard of care for the treatment of IMT, identifying genomic alterations could help to redefine the management of patients with negative-ALK disease. Our review of the literature on IMT and other kinase fusions revealed, in addition to ALK rearrangements, the potential association of ROS1, NTRK, RET, or PDGFR beta alterations with the tumor.

Perianal mammary-type myofibroblastoma

We report a unique case of an extramammary mammary-type myofibroblastoma of the perianal region. The patient was a 40-year old female with no significant past history, who presented with a right side painless perianal mass. Gross examination of the excised mass showed a well-circumscribed, apparently encapsulated, nodular mass weighing 30 g and measuring 5 cm. in the greatest dimension. The cut surface showed solid, yellow homogenous tissue. Microscopically, the neoplasm was composed of bland spindled cells generally arranged into short fascicles with abundant myxoid stroma. The cells stained strongly for desmin and CD34. To our knowledge, a review of the literature discloses only ten cases of extramammary, mammary-type myofibroblastoma.

Inflammatory myofibroblastic tumor of mesentery: a case report

INTRODUCTION

Inflammatory myofibroblastic tumor occurring at intra-abdominal sites in children has rarely been described. In the abdomen, mesentery is a rare location for an inflammatory myofibroblastic tumor.

CASE REPORT

A case report of inflammatory myofibroblastic tumor of mesentery presenting as painless abdominal swelling is presented. Histopathological study of specimen documented the diagnosis. Complete resection of tumor was done with no recurrence seen in follow-up.

Proliferation, ploidy and prognosis in uterine smooth muscle tumours

DNA ploidy, mitotic rate (per 10 high power fields), mitotic index (per 1000 tumour nuclei), Ki-67 labelling index and S phase fraction were measured in 23 uterine leiomyosarcomas and 10 tumours of uncertain malignant potential. Correlations were calculated by Spearmann rank correlation. Univariate survival analysis was performed by log rank analysis and multivariate analysis performed by the Cox linear regression method. Ki-67 index and S phase fraction were significantly higher in leiomyosarcomas than in tumours of uncertain malignant potential. There was significant correlation between mitotic rate, mitotic index, Ki-67 index and S phase fraction in cases of leiomyosarcoma. Fifteen of 22 leiomyosarcomas and one of 10 tumours of uncertain malignant potential were DNA aneuploid. On univariate analysis of all the smooth muscle tumours, DNA ploidy, presence of significant nuclear atypia and presence of coagulative tumour cell necrosis were associated with outcome. Only DNA ploidy was associated with outcome in the group of leiomyosarcomas. On multivariate analysis of all of the smooth muscle tumours, DNA ploidy, age and grade of atypia were independently associated with outcome. No single factor was independently predictive of outcome in the group of leiomyosarcomas. Alternative indices of cell proliferation correlate with mitotic rate in uterine leiomyosarcoma and do not provide additional useful prognostic information. DNA ploidy, age and grade of atypia are independently associated with outcome in uterine smooth muscle tumours and measurement of DNA ploidy may be useful in identification of cases with an adverse prognosis.

Gastrointestinal stromal tumours: correlation of immunophenotype with clinicopathological features

Stromal tumours of the gastrointestinal tract remain a persistent source of controversy with regard to both their proposed lines of differentiation and the difficulty in predicting their biological behaviour. We have examined 60 cases with a panel of seven antibodies directed at the identification of smooth muscular or neural differentiation. In our hands, 36 per cent of cases showed neural differentiation (although only 6.6 per cent expressed S-100 protein); 31 per cent appeared smooth muscular; 20 per cent manifested bidirectional differentiation; and 13 per cent were negative for all the markers used. Histological appearances do not reliably reflect immunophenotype. We have attempted to correlate immunophenotype with the site of the lesions and with their clinical behaviour. Mean follow-up of 5 years was obtained in 42 cases. Tumours with a neural phenotype have the best prognosis. Gastric tumours expressing both desmin and smooth muscle actin (in the absence of other markers) with up to 4 mitoses per 30 HPF behave in a benign fashion. Larger studies are required to substantiate the value of immunophenotyping this complex group of tumours.

Granular cell tumor of the stomach coincident with two early gastric carcinomas

In a 64-yr-old Japanese man, granular cell tumor of the stomach plus two early gastric carcinomas were detected. The granular cell tumor was a 1.5 x 1.5-cm submucosal nodule located in the posterior wall of the fundus. The mucosa adjacent to the granular cell tumor showed two well-differentiated adenocarcinomas restricted to the mucosa, but there was no continuity among these three conditions. This seems to be the first report of this type of association. Immunohistochemical study revealed S-100 protein in the component cells of the granular cell tumor, thereby supporting the proposal that this granular cell is derived from Schwann cells.

Expression of the common acute lymphoblastic leukemia antigen (CD10) in mesenchymal tumors

The expression of the CD10 antigen, formerly designated as common acute lymphoblastic leukemia antigen and recently identified as neutral endopeptidase, was examined immunohistochemically in 26 benign and in 55 malignant mesenchymal tumors. CD10 expression was found in 4 of 4 leiomyomas, 7 of 10 leiomyosarcomas, 1 of 6 rhabdomyosarcomas, 2 of 2 Triton tumors, 1 of 2 aggressive fibromatoses, 1 of 3 fibrosarcomas, 1 of 4 synovial sarcomas, 1 of 1 giant cell tumors of tendon sheath, 4 of 4 malignant fibrous histiocytomas, 3 of 3 Ewing's sarcomas, and 2 of 3 osteosarcomas. Furthermore, CD10 was expressed consistently in the myoepithelial compartment of 12 fibroadenomas and, in 7 of these cases, in a minor stromal cell population, probably of (myo-) fibroblastic origin. Tumors of adipose tissue (4 lipomas, 5 liposarcomas), tumors of autonomic ganglia (2 ganglioneuromas, 1 ganglioneuroblastoma, 2 neuroblastomas), tumors of peripheral nerves with purely schwannian differentiation (7 malignant schwannomas), and tumors of disputed origin were consistently CD10-negative, however, as were single cases of fibroma and chondrosarcoma. These findings indicate that the expression of CD10 is a frequent but not obligatory feature in some mesenchymal tumors. Therefore CD10 is of value in the differential diagnosis of mesenchymal tumors.

Alveolar soft part sarcoma: immunological evidence of rhabdomyoblastic differentiation

Two cases of alveolar soft part sarcoma have been studied immunocytochemically using antisera against epithelial membrane antigen, lysozyme, keratins, S-100 protein, desmin, vimentin, fetal myosin, slow myosin, alpha-skeletal muscle actin, alpha-smooth muscle actin and myoglobin. The neoplastic cells were negative with all antisera employed with the exception of the alpha-skeletal muscle actin antiserum which stained the cytoplasm of numerous neoplastic elements, including the crystalloid rods, typical cytoplasmic inclusions of these tumours. It is suggested that the presence of this protein indicates rhabdomyoblastic differentiation of these tumours.

Granular cell tumours revisited. An immunohistological and ultrastructural study

Twenty-five granular cell tumours were stained with a panel of antibodies to histiocytic, muscle, neural, neural crest, epithelial and endothelial markers. Electron microscopy was also performed in six cases. Twenty-four of the cases were similar morphologically and immunocytochemically. One case with features of an endothelial origin is described. The present study strongly supports the viewpoint that granular cell tumours are a distinct entity rather than being the common appearance of a group of lesions of differing histogenesis. Origin from a neural crest-derived peripheral nerve-related cell is favoured.

Granular cell tumors: evidence for heterogeneous tumor cell differentiation. An immunocytochemical study

Eighteen granular cell tumors from various sites were examined with antisera directed against protein S-100, neuron specific enolase (NSE), alpha-1-antichymotrypsin, and alpha-1-antitrypsin, glial fibrillary acidic protein (GFAP), lysozyme, factor VIII-related antigen, myoglobin and vimentin, as well as with a monoclonal antibody (lu-5) directed against a panepithelial marker. The immunocytochemical reaction pattern of the tumors was heterogeneous. The brain and pituitary tumors and one thyroid tumor reacted for alpha-1-antichymotrypsin and alpha-1-antitrypsin, but not for S-100 protein and NSE. However, tumors from other sites showed immunoreactions for S-100 protein and NSE and some also for vimentin. Reactions for alpha-1-antichymotrypsin and alpha-1-antitrypsin were not observed. All other reactions were similarly negative. We conclude that the morphologically homogeneous group of granular cell tumors is biologically heterogeneous.

Locally aggressive granular cell tumor causing priapism of the crus of the clitoris. A light and ultrastructural study, with observations concerning the pathogenesis of fibrosis of the corpus cavernosum in priapism

A case of focal priapism of the clitoris caused by a microscopic granular cell tumor (GCT) is described. This neoplasm is considered locally aggressive because it invades the lumens of peripheral cavernous sinuses of the crus of the clitoris. Caverns adjacent to those invaded by tumor exhibit stasis, telangiectasia, and necrosis of the smooth muscle of the trabecular wall. These alterations lead to telescoping collapse and compression of the cavernous spaces and culminate in fibrosis. Ultrastructurally, replicated basal lamina is found surrounding clusters of granular cells. We suspect that the multilayered lamina, in addition to being produced by tumor cells, is derived from the trabecular endothelium surrounding the caverns invaded by the GCT. The replication of the basal lamina may be provoked by cycles of injury and repair to these vessels caused by repeated episodes of prolonged vascular stasis. A peculiar large vein with perforating branches was observed in the center of the cavernous spaces of the crus. This vein is not found in normal crura and, therefore, represents a morphologic adaptation created to drain the cavernous spaces.

Granular cell tumors of the breast. Steroid receptor analysis and localization of carcinoembryonic antigen, myoglobin, and S100 protein

Granular cell tumors occur in a variety of sites, including the breast (6%). Origins from histiocytic, myogenic, fibroblastic, and neurogenic elements have been proposed. Female predominance suggests that estrogenic hormones are involved. Four granular cell tumors of the breast and one in an axillary lymph node were studied for sex steroid receptor content, myoglobin, carcinoembryonic antigen, and S100 protein localization. Antimyoglobin antibody did not localize in these tumors. Carcinoembryonic antigen and S100 protein localized in the cytoplasm of these tumors. Neither estrogen nor progesterone receptor protein were present in these tumors in detectable amounts. Ultrastructural features of these granular cell tumors in the breast are similar to those described for extramammary granular cell tumors. These studies agree with previous data that suggest a neurogenic origin for granular cell tumors.

Histogenesis of granular cell tumour--an immunohistochemical and ultrastructural study

Fifteen cases of granular cell tumour of superficial soft tissues or tongue were immunohistochemically evaluated for different types of intermediate filament proteins and for laminin, a glycoprotein of basal laminae. Four of the tumours were studied ultrastructurally. The tumour cells appeared to contain only vimentin-type of intermediate filament protein. The lobules of tumour cells were surrounded by laminin-positive material, but in contrast to schwannomas and neurofibromas, the individual tumour cells were not covered by laminin. In line with the immunohistochemical observations, by electron microscopy basal lamina-like material could not be demonstrated between individual cells, but only surrounding groups of cells. Lysozyme, a histiocytic marker, was absent in the tumour cells. Our results do not confirm any particular cell type for the histogenetic origin of granular cell tumour, but suggest that it may rather be derived from uncommitted possibly nerve-related mesenchymal cells.

Carcinoembryonic antigen like antigen in granular cell myoblastomas. An immunohistochemical study

A series of granular cell myoblastomas (GCM) and other benign and malignant tumours of soft tissue were examined for cytoplasmic content of carcinoembryonic antigen (CEA) by the two-layer conjugated immunoperoxidase technique. Using a commercial rabbit anti-CEA serum only granular cell myoblastomas showed positive cytoplasmic reaction. Pretreatment with periodic acid made this reaction less intense, but when the commercial rabbit anti-CEA serum was absorbed with tissue powder from normal human spleen the positive reaction was totally abolished. It is concluded that the positivity of GCM for CEA using commercial rabbit anti-CEA serum is due to the content of non-specific cross-reacting antigen (NCA) and maybe other cross-reacting glycoproteins in this tumour, and not to CEA as claimed in a previous study.

Granular cell myoblastoma: an immunoperoxidase study using a variety of antisera to human carcinoembryonic antigen

Immunoperoxidase staining using five antisera to human carcinoembryonic antigen (CEA), including a mouse monoclonal antibody, was performed to investigate the expression of CEA reactivity in ten cases of granular cell myoblastoma. The granular cells were negative with four of the antisera although control sections of CEA producing colon carcinoma were positive. The single positive antiserum gave intense granular cytoplasmic staining of all tumour cells in the ten specimens studied. This reactivity was abolished after absorption of the antiserum with a perchloric acid extract of human lung to remove cross-reacting antibodies against non-specific cross-reacting antigen (NCA); a procedure which did not affect the staining of colon carcinoma specimens. The results indicate that the granular cells do not contain CEA but express a related antigen and that care in the choice of primary antiserum is important if the immunocytochemical detection of this antigen is to be used as a diagnostic aid.

Malignant granular cell tumor. Report of a case with special reference to carcinoembryonic antigen

A case of malignant granular cell tumor and its histochemical and electron-microscopic characteristics are reported. This case showed, in addition to the well-known distribution of this type of tumor in subcutaneous fat, mediastinum, retroperitoneum and lungs, multiple foci in the myocardium. Contrary to recent studies reporting the presence of carcinoembryonic antigen (CEA) in benign and malignant granular cell tumors, this case is CEA-negative. We suggest that the reported CEA-reactivity in this type of tumor is probably due to cross-reacting antibodies against antigens, presumably associated with lysosomes.

Oral granular cell myoblastoma: an immunohistochemical study

Immunoperoxidase staining for a variety of antigens was performed on 15 cases of granula cell myoblastoma occurring within the oral tissues. All tumours gave intense intracytoplasmic granular staining for a CEA-related antigen with one rabbit antiserum to CEA (Dakopatts) whereas all were negative with a sheep antiserum to CEA (Seward). None of the tumours were positive for lysozyme, alpha 1 antitrypsin to cathepsin B whereas 12 lesions gave a granular reaction for cathepsin D. All granular cells showed a weak reaction for actin in contrast to the strong cytoplasmic staining found in smooth striated muscle and muscle derived tumours.

Granular cell myoblastoma: positive staining for carcinoembryonic antigen

An immunoperoxidase technique for the detection of carcinoembryonic antigen was applied to 10 cases of granular cell myoblastoma. Consistent, strong, intracytoplasmic granular staining, which can be easily interpreted, was obtained in all cases. Schwannomas, neurofibromas, dermatofibromas, and leiomyomas were negative. The test is helpful in confirming doubtful cases. The results tend to support the suggestion that granular cell myoblastoma is derived from perineural rather than endoneural cells.