Otorhinolaryngologic examination showed a 3.8 cm x 2.5 cm growth right pyriform sinus (PFS), biopsy from which revealed pleomorphic
spindle cell tumor with large hyperchromatic nuclei, prominent nucleoli with frequent mitosis with a mitotic rate of 4 per high-power-field arranged in intersecting fascicles.
The fine needle aspiration biopsy of the mass showed
spindle cell lesion.
Histologically, GISTs are classified as
spindle cell tumors (70%), epithelioid cell tumors (20%), and mixed-type tumors, which are rarely observed.
Microscopically, GIST can show either
spindle cell morphology or epithelioid cell morphology.
Histopathologic examination showed hyperplasia of
spindle cells with tendency toward the pulmonary inflammatory myofibroblastic tumor (IMT) [Figure 1]f1 and [Figure 1]f2.
Cutaneous
spindle cell lesions encompass a heterogeneous group of tumors that range from reactive to benign, borderline, and malignant tumors.
MSP should be considered in the differential diagnosis of tumours with
spindle cell proliferation.
Poorly differentiated
spindle cell neoplasms pose a diagnostic challenge to histopathologists because of a lack of specific morphologic features on standard histopathology.
The
spindle cell variant was included within the embryonal category along with botryoid and anaplastic variants.
Holler et al., "Differential diagnosis of laryngeal
spindle cell carcinoma and inflammatory myofibroblastic tumor--Report of two cases with similar morphology," Diagnostic Pathology, vol.
Authors have emphasized that the most common diagnostic difficulty arises with other benign and malignant
spindle cell tumors (including
spindle cell carcinomas and sarcomas) and fibromatosis [1].
It has multiple subtypes, out of which monophasic (
spindle cell carcinoma) has close histological resemblance to other tumors including fibrosarcoma, leiomyosarcoma, and
spindle cell variant of squamous cell carcinoma that are relatively more common.